linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2 00/63] Introduce strict memcpy() bounds checking
@ 2021-08-18  6:04 Kees Cook
  2021-08-18  6:04 ` [PATCH v2 01/63] ipw2x00: Avoid field-overflowing memcpy() Kees Cook
                   ` (62 more replies)
  0 siblings, 63 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Hi,

This patch series (based on next-20210816) implements stricter (no struct
member overflows) bounds checking for memcpy(), memmove(), and memset()
under CONFIG_FORTIFY_SOURCE. To quote a later patch in the series:

    tl;dr: In order to eliminate a large class of common buffer overflow
    flaws that continue to persist in the kernel, have memcpy() (under
    CONFIG_FORTIFY_SOURCE) perform bounds checking of the destination struct
    member when they have a known size. This would have caught all of the
    memcpy()-related buffer write overflow flaws identified in at least the
    last three years.

As this series introduces various helpers and performs several phases of
treewide cleanups, I'm expecting to carry this series in my tree, so I'd
love to get some Reviews and Acks. Given the size, I've mostly aimed this
series at various mailing lists, otherwise the CC size got really big. :)

I have separated a few things off of this submission, as things continue
to grow:
- run-time bounds checking (which now has a better solution for unknown
			    bounds besides "oh well")
- __alloc_size enablement (sent separately[1])
- -Warray-bounds enablement (several cleanups have been sent)

The remaining portions (here) haven't seen as much change, so I think
it's better to get these compile-time portions landed first -- they're
big enough. My intention is to put this in -next soon via my "overflow"
tree, assuming people are happy with it. :)

Another random thing of note, I'm using the "Enhanced-by:" tag to mean
"this was improved by...", inspired by the existing "Fixed-by:" tag (for
"folded fixes"). "Fixed-by:" seemed inaccurate (it wasn't broken; it is
just better now), and "Suggested-by:" seemed too nebulous (what was
suggested?).

Thanks!

-Kees

[1] https://lore.kernel.org/lkml/20210818050841.2226600-1-keescook@chromium.org/

v2:
- fix CC_IS_CLANG typo (nathan)
- bug.h hunk moved later (ndesaulnier)
- various commit log typos (ndesaulnier)
- omap3isp: fix read source (gustavo)
- struct_group can be variadic (rasmus)
- add struct_group_tagged (dan williams)
- move raw __struct_group() to UAPI (gregkh, dan vetter)
- ibmvscsi: add BUILD_BUG_ON() size checks
- net: use memset_after() instead of struct_group() (jakob)
- swap some memset_after() to memset_startat() for readability
- add missing __NO_FORTIFY to arm boot stub (lkp)
- powerpc signal32 struct_group() added (lkp)
- powerpc sata_fsl struct_group() added
- add fortify failure condition arguments to warning funcs to assist debugging
- add ray_cs compile-time fix
- add flexcan compile-time fix
- add af_iucv compile-time fix
- fix dropped strcpy() compile-time write overflow check
- add missing strscpy() compile-time read overflow check
- fix more boot stub build instances where fortification must be disabled
- add reviewed-bys/acks
v1: https://lore.kernel.org/lkml/20210727205855.411487-1-keescook@chromium.org/

Specifically, this series is logically split into several steps:

Clean up remaining simple compile-time memcpy() warnings:
  ipw2x00: Avoid field-overflowing memcpy()
  net/mlx5e: Avoid field-overflowing memcpy()
  rpmsg: glink: Replace strncpy() with strscpy_pad()
  pcmcia: ray_cs: Split memcpy() to avoid bounds check warning

Introduce struct_group() and apply it treewide to avoid compile-time
memcpy() warnings:
  stddef: Introduce struct_group() helper macro
  cxl/core: Replace unions with struct_group()
  skbuff: Switch structure bounds to struct_group()
  bnxt_en: Use struct_group_attr() for memcpy() region
  mwl8k: Use struct_group() for memcpy() region
  libertas: Use struct_group() for memcpy() region
  libertas_tf: Use struct_group() for memcpy() region
  thermal: intel: int340x_thermal: Use struct_group() for memcpy() region
  iommu/amd: Use struct_group() for memcpy() region
  cxgb3: Use struct_group() for memcpy() region
  intersil: Use struct_group() for memcpy() region
  cxgb4: Use struct_group() for memcpy() region
  bnx2x: Use struct_group() for memcpy() region
  drm/amd/pm: Use struct_group() for memcpy() region
  staging: wlan-ng: Use struct_group() for memcpy() region
  drm/mga/mga_ioc32: Use struct_group() for memcpy() region
  net/mlx5e: Use struct_group() for memcpy() region
  HID: cp2112: Use struct_group() for memcpy() region
  media: omap3isp: Use struct_group() for memcpy() region
  sata_fsl: Use struct_group() for memcpy() region

Prepare fortify for additional hardening:
  compiler_types.h: Remove __compiletime_object_size()
  lib/string: Move helper functions out of string.c
  fortify: Move remaining fortify helpers into fortify-string.h
  fortify: Explicitly disable Clang support
  fortify: Fix dropped strcpy() compile-time write overflow check
  fortify: Prepare to improve strnlen() and strlen() warnings
  fortify: Allow strlen() and strnlen() to pass compile-time known lengths

Add compile-time and run-time tests:
  fortify: Add compile-time FORTIFY_SOURCE tests
  lib: Introduce CONFIG_TEST_MEMCPY

Enable new compile-time memcpy() and memmove() bounds checking:
  fortify: Detect struct member overflows in memcpy() at compile-time
  fortify: Detect struct member overflows in memmove() at compile-time

Clean up remaining simple compile-time memset() warnings:
  scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp

Introduce memset_after() and memset_startat() helpers and apply them
(and struct_group()):
  string.h: Introduce memset_after() for wiping trailing members/padding
  xfrm: Use memset_after() to clear padding
  ipv6: Use memset_after() to zero rt6_info
  netfilter: conntrack: Use memset_startat() to zero struct nf_conn
  net: 802: Use memset_startat() to clear struct fields
  net: dccp: Use memset_startat() for TP zeroing
  net: qede: Use memset_startat() for counters
  mac80211: Use memset_after() to clear tx status
  ath11k: Use memset_startat() for clearing queue descriptors
  iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl
  intel_th: msu: Use memset_startat() for clearing hw header
  IB/mthca: Use memset_startat() for clearing mpt_entry
  btrfs: Use memset_startat() to clear end of struct
  tracing: Use memset_startat() to zero struct trace_iterator
  drbd: Use struct_group() to zero algs
  cm4000_cs: Use struct_group() to zero struct cm4000_dev region
  KVM: x86: Use struct_group() to zero decode cache
  dm integrity: Use struct_group() to zero struct journal_sector
  HID: roccat: Use struct_group() to zero kone_mouse_event
  RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  powerpc/signal32: Use struct_group() to zero spe regs
  ethtool: stats: Use struct_group() to clear all stats at once
  can: flexcan: Use struct_group() to zero struct flexcan_regs regions
  net/af_iucv: Use struct_group() to zero struct iucv_sock region
  powerpc: Split memset() to avoid multi-field overflow

Enable new compile-time memset() bounds checking:
  fortify: Detect struct member overflows in memset() at compile-time

Enable Clang support:
  fortify: Work around Clang inlining bugs

 arch/arm/boot/compressed/string.c             |   1 +
 arch/powerpc/include/asm/processor.h          |   6 +-
 arch/powerpc/kernel/signal_32.c               |   6 +-
 arch/s390/lib/string.c                        |   3 +
 arch/x86/boot/compressed/misc.c               |   3 +-
 arch/x86/boot/compressed/misc.h               |   2 +
 arch/x86/boot/compressed/pgtable_64.c         |   2 +
 arch/x86/kvm/emulate.c                        |   3 +-
 arch/x86/kvm/kvm_emulate.h                    |  19 +-
 arch/x86/lib/memcpy_32.c                      |   1 +
 arch/x86/lib/string_32.c                      |   1 +
 drivers/ata/sata_fsl.c                        |  10 +-
 drivers/block/drbd/drbd_main.c                |   3 +-
 drivers/block/drbd/drbd_protocol.h            |   6 +-
 drivers/block/drbd/drbd_receiver.c            |   3 +-
 drivers/char/pcmcia/cm4000_cs.c               |   9 +-
 drivers/cxl/cxl.h                             |  61 +---
 drivers/gpu/drm/amd/include/atomfirmware.h    |   9 +-
 .../drm/amd/pm/inc/smu11_driver_if_arcturus.h |   3 +-
 .../drm/amd/pm/inc/smu11_driver_if_navi10.h   |   3 +-
 .../amd/pm/inc/smu13_driver_if_aldebaran.h    |   3 +-
 .../gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c   |  12 +-
 .../drm/amd/pm/swsmu/smu13/aldebaran_ppt.c    |   6 +-
 drivers/gpu/drm/mga/mga_ioc32.c               |  27 +-
 drivers/hid/hid-cp2112.c                      |  14 +-
 drivers/hid/hid-roccat-kone.c                 |   2 +-
 drivers/hid/hid-roccat-kone.h                 |  12 +-
 drivers/hwtracing/intel_th/msu.c              |   4 +-
 drivers/infiniband/hw/cxgb4/cm.c              |   5 +-
 drivers/infiniband/hw/mlx5/mlx5_ib.h          |   4 +-
 drivers/infiniband/hw/mthca/mthca_mr.c        |   3 +-
 drivers/iommu/amd/init.c                      |   9 +-
 drivers/macintosh/smu.c                       |   3 +-
 drivers/md/dm-integrity.c                     |   9 +-
 drivers/media/platform/omap3isp/ispstat.c     |   5 +-
 drivers/net/can/flexcan.c                     |  68 ++--
 .../net/ethernet/broadcom/bnx2x/bnx2x_stats.c |   7 +-
 .../net/ethernet/broadcom/bnx2x/bnx2x_stats.h |  14 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c |   4 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h |  14 +-
 drivers/net/ethernet/chelsio/cxgb3/sge.c      |   9 +-
 drivers/net/ethernet/chelsio/cxgb4/sge.c      |   8 +-
 drivers/net/ethernet/chelsio/cxgb4/t4_msg.h   |   2 +-
 drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h |  10 +-
 drivers/net/ethernet/chelsio/cxgb4vf/sge.c    |   7 +-
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |   4 +-
 .../net/ethernet/mellanox/mlx5/core/en/xdp.c  |   4 +-
 .../net/ethernet/mellanox/mlx5/core/en_tx.c   |   2 +-
 drivers/net/ethernet/qlogic/qede/qede_main.c  |   2 +-
 drivers/net/wireguard/queueing.h              |   4 +-
 drivers/net/wireless/ath/ath11k/hal_rx.c      |  13 +-
 drivers/net/wireless/ath/carl9170/tx.c        |  11 +-
 .../net/wireless/intel/ipw2x00/libipw_rx.c    |  56 +---
 .../net/wireless/intersil/hostap/hostap_hw.c  |   5 +-
 .../wireless/intersil/hostap/hostap_wlan.h    |  14 +-
 drivers/net/wireless/intersil/p54/txrx.c      |   6 +-
 drivers/net/wireless/marvell/libertas/host.h  |  10 +-
 drivers/net/wireless/marvell/libertas/tx.c    |   5 +-
 .../marvell/libertas_tf/libertas_tf.h         |  10 +-
 .../net/wireless/marvell/libertas_tf/main.c   |   3 +-
 drivers/net/wireless/marvell/mwl8k.c          |  10 +-
 drivers/net/wireless/ray_cs.c                 |   4 +-
 drivers/rpmsg/qcom_glink_native.c             |   2 +-
 drivers/scsi/ibmvscsi/ibmvscsi.c              |   3 +-
 drivers/staging/wlan-ng/hfa384x.h             |  16 +-
 drivers/staging/wlan-ng/hfa384x_usb.c         |   4 +-
 .../intel/int340x_thermal/acpi_thermal_rel.c  |   5 +-
 .../intel/int340x_thermal/acpi_thermal_rel.h  |  48 +--
 fs/btrfs/root-tree.c                          |   6 +-
 include/linux/compiler-gcc.h                  |   2 -
 include/linux/compiler_types.h                |   4 -
 include/linux/fortify-string.h                | 308 +++++++++++++-----
 include/linux/if_vlan.h                       |   6 +-
 include/linux/skbuff.h                        |   9 +-
 include/linux/stddef.h                        |  47 +++
 include/linux/string.h                        |  43 ++-
 include/linux/thread_info.h                   |   2 +-
 include/net/iucv/af_iucv.h                    |  10 +-
 include/net/mac80211.h                        |   7 +-
 include/uapi/drm/mga_drm.h                    |  22 +-
 include/uapi/linux/omap3isp.h                 |  21 +-
 include/uapi/linux/stddef.h                   |  21 ++
 kernel/trace/trace.c                          |   4 +-
 lib/.gitignore                                |   2 +
 lib/Kconfig.debug                             |   7 +
 lib/Makefile                                  |  35 ++
 lib/string.c                                  | 210 +-----------
 lib/string_helpers.c                          | 201 ++++++++++++
 lib/test_fortify/read_overflow-memchr.c       |   5 +
 lib/test_fortify/read_overflow-memchr_inv.c   |   5 +
 lib/test_fortify/read_overflow-memcmp.c       |   5 +
 lib/test_fortify/read_overflow-memscan.c      |   5 +
 lib/test_fortify/read_overflow2-memcmp.c      |   5 +
 lib/test_fortify/read_overflow2-memcpy.c      |   5 +
 lib/test_fortify/read_overflow2-memmove.c     |   5 +
 .../read_overflow2_field-memcpy.c             |   5 +
 .../read_overflow2_field-memmove.c            |   5 +
 lib/test_fortify/test_fortify.h               |  35 ++
 lib/test_fortify/write_overflow-memcpy.c      |   5 +
 lib/test_fortify/write_overflow-memmove.c     |   5 +
 lib/test_fortify/write_overflow-memset.c      |   5 +
 lib/test_fortify/write_overflow-strcpy-lit.c  |   5 +
 lib/test_fortify/write_overflow-strcpy.c      |   5 +
 lib/test_fortify/write_overflow-strlcpy-src.c |   5 +
 lib/test_fortify/write_overflow-strlcpy.c     |   5 +
 lib/test_fortify/write_overflow-strncpy-src.c |   5 +
 lib/test_fortify/write_overflow-strncpy.c     |   5 +
 lib/test_fortify/write_overflow-strscpy.c     |   5 +
 .../write_overflow_field-memcpy.c             |   5 +
 .../write_overflow_field-memmove.c            |   5 +
 .../write_overflow_field-memset.c             |   5 +
 lib/test_memcpy.c                             | 288 ++++++++++++++++
 net/802/hippi.c                               |   2 +-
 net/core/skbuff.c                             |  14 +-
 net/dccp/trace.h                              |   4 +-
 net/ethtool/stats.c                           |  15 +-
 net/ipv6/route.c                              |   4 +-
 net/iucv/af_iucv.c                            |   2 +-
 net/netfilter/nf_conntrack_core.c             |   4 +-
 net/xfrm/xfrm_policy.c                        |   4 +-
 net/xfrm/xfrm_user.c                          |   2 +-
 scripts/test_fortify.sh                       |  59 ++++
 security/Kconfig                              |   3 +
 124 files changed, 1489 insertions(+), 686 deletions(-)
 create mode 100644 lib/test_fortify/read_overflow-memchr.c
 create mode 100644 lib/test_fortify/read_overflow-memchr_inv.c
 create mode 100644 lib/test_fortify/read_overflow-memcmp.c
 create mode 100644 lib/test_fortify/read_overflow-memscan.c
 create mode 100644 lib/test_fortify/read_overflow2-memcmp.c
 create mode 100644 lib/test_fortify/read_overflow2-memcpy.c
 create mode 100644 lib/test_fortify/read_overflow2-memmove.c
 create mode 100644 lib/test_fortify/read_overflow2_field-memcpy.c
 create mode 100644 lib/test_fortify/read_overflow2_field-memmove.c
 create mode 100644 lib/test_fortify/test_fortify.h
 create mode 100644 lib/test_fortify/write_overflow-memcpy.c
 create mode 100644 lib/test_fortify/write_overflow-memmove.c
 create mode 100644 lib/test_fortify/write_overflow-memset.c
 create mode 100644 lib/test_fortify/write_overflow-strcpy-lit.c
 create mode 100644 lib/test_fortify/write_overflow-strcpy.c
 create mode 100644 lib/test_fortify/write_overflow-strlcpy-src.c
 create mode 100644 lib/test_fortify/write_overflow-strlcpy.c
 create mode 100644 lib/test_fortify/write_overflow-strncpy-src.c
 create mode 100644 lib/test_fortify/write_overflow-strncpy.c
 create mode 100644 lib/test_fortify/write_overflow-strscpy.c
 create mode 100644 lib/test_fortify/write_overflow_field-memcpy.c
 create mode 100644 lib/test_fortify/write_overflow_field-memmove.c
 create mode 100644 lib/test_fortify/write_overflow_field-memset.c
 create mode 100644 lib/test_memcpy.c
 create mode 100644 scripts/test_fortify.sh

-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 01/63] ipw2x00: Avoid field-overflowing memcpy()
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 02/63] net/mlx5e: " Kees Cook
                   ` (61 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Stanislav Yakovlev, Kalle Valo, David S. Miller,
	Jakub Kicinski, linux-wireless, netdev, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

libipw_read_qos_param_element() copies a struct libipw_info_element
into a struct libipw_qos_information_element, but is actually wanting to
copy into the larger struct libipw_qos_parameter_info (the contents of
ac_params_record[] is later examined). Refactor the routine to perform
centralized checks, and copy the entire contents directly (since the id
and len members match the elementID and length members):

struct libipw_info_element {
        u8 id;
        u8 len;
        u8 data[];
} __packed;

struct libipw_qos_information_element {
        u8 elementID;
        u8 length;
        u8 qui[QOS_OUI_LEN];
        u8 qui_type;
        u8 qui_subtype;
        u8 version;
        u8 ac_info;
} __packed;

struct libipw_qos_parameter_info {
        struct libipw_qos_information_element info_element;
        u8 reserved;
        struct libipw_qos_ac_parameter ac_params_record[QOS_QUEUE_NUM];
} __packed;

Cc: Stanislav Yakovlev <stas.yakovlev@gmail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 .../net/wireless/intel/ipw2x00/libipw_rx.c    | 56 ++++++-------------
 1 file changed, 17 insertions(+), 39 deletions(-)

diff --git a/drivers/net/wireless/intel/ipw2x00/libipw_rx.c b/drivers/net/wireless/intel/ipw2x00/libipw_rx.c
index 5a2a723e480b..7a684b76f39b 100644
--- a/drivers/net/wireless/intel/ipw2x00/libipw_rx.c
+++ b/drivers/net/wireless/intel/ipw2x00/libipw_rx.c
@@ -927,7 +927,8 @@ static u8 qos_oui[QOS_OUI_LEN] = { 0x00, 0x50, 0xF2 };
 static int libipw_verify_qos_info(struct libipw_qos_information_element
 				     *info_element, int sub_type)
 {
-
+	if (info_element->elementID != QOS_ELEMENT_ID)
+		return -1;
 	if (info_element->qui_subtype != sub_type)
 		return -1;
 	if (memcmp(info_element->qui, qos_oui, QOS_OUI_LEN))
@@ -943,57 +944,34 @@ static int libipw_verify_qos_info(struct libipw_qos_information_element
 /*
  * Parse a QoS parameter element
  */
-static int libipw_read_qos_param_element(struct libipw_qos_parameter_info
-					    *element_param, struct libipw_info_element
-					    *info_element)
+static int libipw_read_qos_param_element(
+			struct libipw_qos_parameter_info *element_param,
+			struct libipw_info_element *info_element)
 {
-	int ret = 0;
-	u16 size = sizeof(struct libipw_qos_parameter_info) - 2;
+	size_t size = sizeof(*element_param);
 
-	if ((info_element == NULL) || (element_param == NULL))
+	if (!element_param || !info_element || info_element->len != size - 2)
 		return -1;
 
-	if (info_element->id == QOS_ELEMENT_ID && info_element->len == size) {
-		memcpy(element_param->info_element.qui, info_element->data,
-		       info_element->len);
-		element_param->info_element.elementID = info_element->id;
-		element_param->info_element.length = info_element->len;
-	} else
-		ret = -1;
-	if (ret == 0)
-		ret = libipw_verify_qos_info(&element_param->info_element,
-						QOS_OUI_PARAM_SUB_TYPE);
-	return ret;
+	memcpy(element_param, info_element, size);
+	return libipw_verify_qos_info(&element_param->info_element,
+				      QOS_OUI_PARAM_SUB_TYPE);
 }
 
 /*
  * Parse a QoS information element
  */
-static int libipw_read_qos_info_element(struct
-					   libipw_qos_information_element
-					   *element_info, struct libipw_info_element
-					   *info_element)
+static int libipw_read_qos_info_element(
+			struct libipw_qos_information_element *element_info,
+			struct libipw_info_element *info_element)
 {
-	int ret = 0;
-	u16 size = sizeof(struct libipw_qos_information_element) - 2;
+	size_t size = sizeof(struct libipw_qos_information_element) - 2;
 
-	if (element_info == NULL)
+	if (!element_info || !info_element || info_element->len != size - 2)
 		return -1;
-	if (info_element == NULL)
-		return -1;
-
-	if ((info_element->id == QOS_ELEMENT_ID) && (info_element->len == size)) {
-		memcpy(element_info->qui, info_element->data,
-		       info_element->len);
-		element_info->elementID = info_element->id;
-		element_info->length = info_element->len;
-	} else
-		ret = -1;
 
-	if (ret == 0)
-		ret = libipw_verify_qos_info(element_info,
-						QOS_OUI_INFO_SUB_TYPE);
-	return ret;
+	memcpy(element_info, info_element, size);
+	return libipw_verify_qos_info(element_info, QOS_OUI_INFO_SUB_TYPE);
 }
 
 /*
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 02/63] net/mlx5e: Avoid field-overflowing memcpy()
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
  2021-08-18  6:04 ` [PATCH v2 01/63] ipw2x00: Avoid field-overflowing memcpy() Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 03/63] rpmsg: glink: Replace strncpy() with strscpy_pad() Kees Cook
                   ` (60 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Saeed Mahameed, Leon Romanovsky, David S. Miller,
	Jakub Kicinski, Alexei Starovoitov, Daniel Borkmann,
	Jesper Dangaard Brouer, John Fastabend, netdev, linux-rdma, bpf,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use flexible arrays instead of zero-element arrays (which look like they
are always overflowing) and split the cross-field memcpy() into two halves
that can be appropriately bounds-checked by the compiler.

We were doing:

	#define ETH_HLEN  14
	#define VLAN_HLEN  4
	...
	#define MLX5E_XDP_MIN_INLINE (ETH_HLEN + VLAN_HLEN)
	...
        struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(wq, pi);
	...
        struct mlx5_wqe_eth_seg  *eseg = &wqe->eth;
        struct mlx5_wqe_data_seg *dseg = wqe->data;
	...
	memcpy(eseg->inline_hdr.start, xdptxd->data, MLX5E_XDP_MIN_INLINE);

target is wqe->eth.inline_hdr.start (which the compiler sees as being
2 bytes in size), but copying 18, intending to write across start
(really vlan_tci, 2 bytes). The remaining 16 bytes get written into
wqe->data[0], covering byte_count (4 bytes), lkey (4 bytes), and addr
(8 bytes).

struct mlx5e_tx_wqe {
        struct mlx5_wqe_ctrl_seg   ctrl;                 /*     0    16 */
        struct mlx5_wqe_eth_seg    eth;                  /*    16    16 */
        struct mlx5_wqe_data_seg   data[];               /*    32     0 */

        /* size: 32, cachelines: 1, members: 3 */
        /* last cacheline: 32 bytes */
};

struct mlx5_wqe_eth_seg {
        u8                         swp_outer_l4_offset;  /*     0     1 */
        u8                         swp_outer_l3_offset;  /*     1     1 */
        u8                         swp_inner_l4_offset;  /*     2     1 */
        u8                         swp_inner_l3_offset;  /*     3     1 */
        u8                         cs_flags;             /*     4     1 */
        u8                         swp_flags;            /*     5     1 */
        __be16                     mss;                  /*     6     2 */
        __be32                     flow_table_metadata;  /*     8     4 */
        union {
                struct {
                        __be16     sz;                   /*    12     2 */
                        u8         start[2];             /*    14     2 */
                } inline_hdr;                            /*    12     4 */
                struct {
                        __be16     type;                 /*    12     2 */
                        __be16     vlan_tci;             /*    14     2 */
                } insert;                                /*    12     4 */
                __be32             trailer;              /*    12     4 */
        };                                               /*    12     4 */

        /* size: 16, cachelines: 1, members: 9 */
        /* last cacheline: 16 bytes */
};

struct mlx5_wqe_data_seg {
        __be32                     byte_count;           /*     0     4 */
        __be32                     lkey;                 /*     4     4 */
        __be64                     addr;                 /*     8     8 */

        /* size: 16, cachelines: 1, members: 3 */
        /* last cacheline: 16 bytes */
};

So, split the memcpy() so the compiler can reason about the buffer
sizes.

"pahole" shows no size nor member offset changes to struct mlx5e_tx_wqe
nor struct mlx5e_umr_wqe. "objdump -d" shows no meaningful object
code changes (i.e. only source line number induced differences and
optimizations).

Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: bpf@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/en.h     | 4 ++--
 drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 4f6897c1ea8d..8997476c20cc 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -200,7 +200,7 @@ static inline int mlx5e_get_max_num_channels(struct mlx5_core_dev *mdev)
 struct mlx5e_tx_wqe {
 	struct mlx5_wqe_ctrl_seg ctrl;
 	struct mlx5_wqe_eth_seg  eth;
-	struct mlx5_wqe_data_seg data[0];
+	struct mlx5_wqe_data_seg data[];
 };
 
 struct mlx5e_rx_wqe_ll {
@@ -216,7 +216,7 @@ struct mlx5e_umr_wqe {
 	struct mlx5_wqe_ctrl_seg       ctrl;
 	struct mlx5_wqe_umr_ctrl_seg   uctrl;
 	struct mlx5_mkey_seg           mkc;
-	struct mlx5_mtt                inline_mtts[0];
+	struct mlx5_mtt                inline_mtts[];
 };
 
 extern const char mlx5e_self_tests[][ETH_GSTRING_LEN];
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 2f0df5cc1a2d..efae2444c26f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -341,8 +341,10 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
 
 	/* copy the inline part if required */
 	if (sq->min_inline_mode != MLX5_INLINE_MODE_NONE) {
-		memcpy(eseg->inline_hdr.start, xdptxd->data, MLX5E_XDP_MIN_INLINE);
+		memcpy(eseg->inline_hdr.start, xdptxd->data, sizeof(eseg->inline_hdr.start));
 		eseg->inline_hdr.sz = cpu_to_be16(MLX5E_XDP_MIN_INLINE);
+		memcpy(dseg, xdptxd->data + sizeof(eseg->inline_hdr.start),
+		       MLX5E_XDP_MIN_INLINE - sizeof(eseg->inline_hdr.start));
 		dma_len  -= MLX5E_XDP_MIN_INLINE;
 		dma_addr += MLX5E_XDP_MIN_INLINE;
 		dseg++;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 03/63] rpmsg: glink: Replace strncpy() with strscpy_pad()
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
  2021-08-18  6:04 ` [PATCH v2 01/63] ipw2x00: Avoid field-overflowing memcpy() Kees Cook
  2021-08-18  6:04 ` [PATCH v2 02/63] net/mlx5e: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 04/63] pcmcia: ray_cs: Split memcpy() to avoid bounds check warning Kees Cook
                   ` (59 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Andy Gross, Bjorn Andersson, Ohad Ben-Cohen,
	Mathieu Poirier, linux-arm-msm, linux-remoteproc,
	Gustavo A . R . Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

The use of strncpy() is considered deprecated for NUL-terminated
strings[1]. Replace strncpy() with strscpy_pad() (as it seems this case
expects the NUL padding to fill the allocation following the flexible
array). This additionally silences a warning seen when building under
-Warray-bounds:

./include/linux/fortify-string.h:38:30: warning: '__builtin_strncpy' offset 24 from the object at '__mptr' is out of the bounds of referenced subobject 'data' with type 'u8[]' {aka 'unsigned char[]'} at offset 24 [-Warray-bounds]
   38 | #define __underlying_strncpy __builtin_strncpy
      |                              ^
./include/linux/fortify-string.h:50:9: note: in expansion of macro '__underlying_strncpy'
   50 |  return __underlying_strncpy(p, q, size);
      |         ^~~~~~~~~~~~~~~~~~~~
drivers/rpmsg/qcom_glink_native.c: In function 'qcom_glink_work':
drivers/rpmsg/qcom_glink_native.c:36:5: note: subobject 'data' declared here
   36 |  u8 data[];
      |     ^~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-remoteproc@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728020745.GB35706@embeddedor
---
 drivers/rpmsg/qcom_glink_native.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 05533c71b10e..c7b9de655080 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -1440,7 +1440,7 @@ static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
 		}
 
 		rpdev->ept = &channel->ept;
-		strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
+		strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
 		rpdev->src = RPMSG_ADDR_ANY;
 		rpdev->dst = RPMSG_ADDR_ANY;
 		rpdev->ops = &glink_device_ops;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 04/63] pcmcia: ray_cs: Split memcpy() to avoid bounds check warning
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (2 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 03/63] rpmsg: glink: Replace strncpy() with strscpy_pad() Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 05/63] stddef: Introduce struct_group() helper macro Kees Cook
                   ` (58 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Kalle Valo, David S. Miller, Jakub Kicinski,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Split memcpy() for each address range to help memcpy() correctly reason
about the bounds checking. Avoids the future warning:

In function 'fortify_memcpy_chk',
    inlined from 'memcpy_toio' at ./include/asm-generic/io.h:1204:2,
    inlined from 'ray_build_header.constprop' at drivers/net/wireless/ray_cs.c:984:3:
./include/linux/fortify-string.h:285:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
  285 |    __write_overflow_field(p_size_field, size);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/ray_cs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ray_cs.c b/drivers/net/wireless/ray_cs.c
index 590bd974d94f..d57bbe551630 100644
--- a/drivers/net/wireless/ray_cs.c
+++ b/drivers/net/wireless/ray_cs.c
@@ -982,7 +982,9 @@ AP to AP	1	1	dest AP		src AP		dest	source
 	if (local->net_type == ADHOC) {
 		writeb(0, &ptx->mac.frame_ctl_2);
 		memcpy_toio(ptx->mac.addr_1, ((struct ethhdr *)data)->h_dest,
-			    2 * ADDRLEN);
+			    ADDRLEN);
+		memcpy_toio(ptx->mac.addr_2, ((struct ethhdr *)data)->h_source,
+			    ADDRLEN);
 		memcpy_toio(ptx->mac.addr_3, local->bss_id, ADDRLEN);
 	} else { /* infrastructure */
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 05/63] stddef: Introduce struct_group() helper macro
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (3 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 04/63] pcmcia: ray_cs: Split memcpy() to avoid bounds check warning Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18 22:35   ` Dan Williams
  2021-08-18  6:04 ` [PATCH v2 06/63] cxl/core: Replace unions with struct_group() Kees Cook
                   ` (57 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Keith Packard, Gustavo A . R . Silva,
	Rasmus Villemoes, Dan Williams, Daniel Vetter,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, linux-hardening

Kernel code has a regular need to describe groups of members within a
structure usually when they need to be copied or initialized separately
from the rest of the surrounding structure. The generally accepted design
pattern in C is to use a named sub-struct:

	struct foo {
		int one;
		struct {
			int two;
			int three, four;
		} thing;
		int five;
	};

This would allow for traditional references and sizing:

	memcpy(&dst.thing, &src.thing, sizeof(dst.thing));

However, doing this would mean that referencing struct members enclosed
by such named structs would always require including the sub-struct name
in identifiers:

	do_something(dst.thing.three);

This has tended to be quite inflexible, especially when such groupings
need to be added to established code which causes huge naming churn.
Three workarounds exist in the kernel for this problem, and each have
other negative properties.

To avoid the naming churn, there is a design pattern of adding macro
aliases for the named struct:

	#define f_three thing.three

This ends up polluting the global namespace, and makes it difficult to
search for identifiers.

Another common work-around in kernel code avoids the pollution by avoiding
the named struct entirely, instead identifying the group's boundaries using
either a pair of empty anonymous structs of a pair of zero-element arrays:

	struct foo {
		int one;
		struct { } start;
		int two;
		int three, four;
		struct { } finish;
		int five;
	};

	struct foo {
		int one;
		int start[0];
		int two;
		int three, four;
		int finish[0];
		int five;
	};

This allows code to avoid needing to use a sub-struct named for member
references within the surrounding structure, but loses the benefits of
being able to actually use such a struct, making it rather fragile. Using
these requires open-coded calculation of sizes and offsets. The efforts
made to avoid common mistakes include lots of comments, or adding various
BUILD_BUG_ON()s. Such code is left with no way for the compiler to reason
about the boundaries (e.g. the "start" object looks like it's 0 bytes
in length), making bounds checking depend on open-coded calculations:

	if (length > offsetof(struct foo, finish) -
		     offsetof(struct foo, start))
		return -EINVAL;
	memcpy(&dst.start, &src.start, offsetof(struct foo, finish) -
				       offsetof(struct foo, start));

However, the vast majority of places in the kernel that operate on
groups of members do so without any identification of the grouping,
relying either on comments or implicit knowledge of the struct contents,
which is even harder for the compiler to reason about, and results in
even more fragile manual sizing, usually depending on member locations
outside of the region (e.g. to copy "two" and "three", use the start of
"four" to find the size):

	BUILD_BUG_ON((offsetof(struct foo, four) <
		      offsetof(struct foo, two)) ||
		     (offsetof(struct foo, four) <
		      offsetof(struct foo, three));
	if (length > offsetof(struct foo, four) -
		     offsetof(struct foo, two))
		return -EINVAL;
	memcpy(&dst.two, &src.two, length);

In order to have a regular programmatic way to describe a struct
region that can be used for references and sizing, can be examined for
bounds checking, avoids forcing the use of intermediate identifiers,
and avoids polluting the global namespace, introduce the struct_group()
macro. This macro wraps the member declarations to create an anonymous
union of an anonymous struct (no intermediate name) and a named struct
(for references and sizing):

	struct foo {
		int one;
		struct_group(thing,
			int two;
			int three, four;
		);
		int five;
	};

	if (length > sizeof(src.thing))
		return -EINVAL;
	memcpy(&dst.thing, &src.thing, length);
	do_something(dst.three);

There are some rare cases where the resulting struct_group() needs
attributes added, so struct_group_attr() is also introduced to allow
for specifying struct attributes (e.g. __align(x) or __packed).
Additionally, there are places where such declarations would like to
have the struct be typed, so struct_group_typed() is added.

Given there is a need for a handful of UAPI uses too, the underlying
__struct_group() macro has been defined in UAPI so it can be used there
too.

Co-developed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728023217.GC35706@embeddedor
Enhanced-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/lkml/41183a98-bdb9-4ad6-7eab-5a7292a6df84@rasmusvillemoes.dk
Enhanced-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com
Enhanced-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local
---
 include/linux/stddef.h      | 47 +++++++++++++++++++++++++++++++++++++
 include/uapi/linux/stddef.h | 21 +++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/include/linux/stddef.h b/include/linux/stddef.h
index 998a4ba28eba..f2aefdb22d1d 100644
--- a/include/linux/stddef.h
+++ b/include/linux/stddef.h
@@ -36,4 +36,51 @@ enum {
 #define offsetofend(TYPE, MEMBER) \
 	(offsetof(TYPE, MEMBER)	+ sizeof_field(TYPE, MEMBER))
 
+/**
+ * struct_group(NAME, MEMBERS)
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members.
+ *
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @MEMBERS: The member declarations for the mirrored structs
+ */
+#define struct_group(NAME, MEMBERS...)	\
+	__struct_group(/* no tag */, NAME, /* no attrs */, MEMBERS)
+
+/**
+ * struct_group_attr(NAME, ATTRS, MEMBERS)
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members. Includes structure attributes argument.
+ *
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes
+ * @MEMBERS: The member declarations for the mirrored structs
+ */
+#define struct_group_attr(NAME, ATTRS, MEMBERS...) \
+	__struct_group(/* no tag */, NAME, ATTRS, MEMBERS)
+
+/**
+ * struct_group_tagged(TAG, NAME, MEMBERS)
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members. Includes struct tag argument for the named copy.
+ *
+ * @TAG: The tag name for the named sub-struct
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @MEMBERS: The member declarations for the mirrored structs
+ */
+#define struct_group_tagged(TAG, NAME, MEMBERS...) \
+	__struct_group(TAG, NAME, /* no attrs */, MEMBERS)
+
 #endif
diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h
index ee8220f8dcf5..0fbdf2f711aa 100644
--- a/include/uapi/linux/stddef.h
+++ b/include/uapi/linux/stddef.h
@@ -4,3 +4,24 @@
 #ifndef __always_inline
 #define __always_inline inline
 #endif
+
+/**
+ * __struct_group(TAG, NAME, ATTRS, MEMBERS)
+ *
+ * Used to create an anonymous union of two structs with identical layout
+ * and size: one anonymous and one named. The former's members can be used
+ * normally without sub-struct naming, and the latter can be used to
+ * reason about the start, end, and size of the group of struct members.
+ * The named struct can also be explicitly tagged, as well as both having
+ * struct attributes.
+ *
+ * @TAG: The tag name for the named sub-struct (usually empty)
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes (usually empty)
+ * @MEMBERS: The member declarations for the mirrored structs
+ */
+#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
+	union { \
+		struct { MEMBERS } ATTRS; \
+		struct TAG { MEMBERS } ATTRS NAME; \
+	}
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 06/63] cxl/core: Replace unions with struct_group()
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (4 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 05/63] stddef: Introduce struct_group() helper macro Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18 22:36   ` Dan Williams
  2021-08-18  6:04 ` [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group() Kees Cook
                   ` (56 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Alison Schofield, Vishal Verma, Ira Weiny,
	Ben Widawsky, linux-cxl, Dan Williams, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

Use the newly introduced struct_group_typed() macro to clean up the
declaration of struct cxl_regs.

Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: linux-cxl@vger.kernel.org
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/cxl/cxl.h | 61 ++++++++++++++---------------------------------
 1 file changed, 18 insertions(+), 43 deletions(-)

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 53927f9fa77e..9db0c402c9ce 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -75,52 +75,27 @@ static inline int cxl_hdm_decoder_count(u32 cap_hdr)
 #define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
 #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
 
-#define CXL_COMPONENT_REGS() \
-	void __iomem *hdm_decoder
-
-#define CXL_DEVICE_REGS() \
-	void __iomem *status; \
-	void __iomem *mbox; \
-	void __iomem *memdev
-
-/* See note for 'struct cxl_regs' for the rationale of this organization */
-/*
- * CXL_COMPONENT_REGS - Common set of CXL Component register block base pointers
- * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
- */
-struct cxl_component_regs {
-	CXL_COMPONENT_REGS();
-};
-
-/* See note for 'struct cxl_regs' for the rationale of this organization */
-/*
- * CXL_DEVICE_REGS - Common set of CXL Device register block base pointers
- * @status: CXL 2.0 8.2.8.3 Device Status Registers
- * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
- * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
- */
-struct cxl_device_regs {
-	CXL_DEVICE_REGS();
-};
-
 /*
- * Note, the anonymous union organization allows for per
- * register-block-type helper routines, without requiring block-type
- * agnostic code to include the prefix.
+ * Using struct_group() allows for per register-block-type helper routines,
+ * without requiring block-type agnostic code to include the prefix.
  */
 struct cxl_regs {
-	union {
-		struct {
-			CXL_COMPONENT_REGS();
-		};
-		struct cxl_component_regs component;
-	};
-	union {
-		struct {
-			CXL_DEVICE_REGS();
-		};
-		struct cxl_device_regs device_regs;
-	};
+	/*
+	 * Common set of CXL Component register block base pointers
+	 * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
+	 */
+	struct_group_tagged(cxl_component_regs, component,
+		void __iomem *hdm_decoder;
+	);
+	/*
+	 * Common set of CXL Device register block base pointers
+	 * @status: CXL 2.0 8.2.8.3 Device Status Registers
+	 * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
+	 * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
+	 */
+	struct_group_tagged(cxl_device_regs, device_regs,
+		void __iomem *status, *mbox, *memdev;
+	);
 };
 
 struct cxl_reg_map {
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group()
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (5 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 06/63] cxl/core: Replace unions with struct_group() Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-09-01 13:46   ` Jason A. Donenfeld
  2021-08-18  6:04 ` [PATCH v2 08/63] bnxt_en: Use struct_group_attr() for memcpy() region Kees Cook
                   ` (55 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Jason A. Donenfeld, David S. Miller, Jakub Kicinski,
	Jonathan Lemon, Alexander Lobakin, Jakub Sitnicki, Marco Elver,
	Willem de Bruijn, wireguard, netdev, Gustavo A . R . Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Replace the existing empty member position markers "headers_start" and
"headers_end" with a struct_group(). This will allow memcpy() and sizeof()
to more easily reason about sizes, and improve readability.

"pahole" shows no size nor member offset changes to struct sk_buff.
"objdump -d" shows no object code changes (outside of WARNs affected by
source line number changes).

Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Marco Elver <elver@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: wireguard@lists.zx2c4.com
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728035006.GD35706@embeddedor
---
 drivers/net/wireguard/queueing.h |  4 +---
 include/linux/skbuff.h           |  9 ++++-----
 net/core/skbuff.c                | 14 +++++---------
 3 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h
index 4ef2944a68bc..52da5e963003 100644
--- a/drivers/net/wireguard/queueing.h
+++ b/drivers/net/wireguard/queueing.h
@@ -79,9 +79,7 @@ static inline void wg_reset_packet(struct sk_buff *skb, bool encapsulating)
 	u8 sw_hash = skb->sw_hash;
 	u32 hash = skb->hash;
 	skb_scrub_packet(skb, true);
-	memset(&skb->headers_start, 0,
-	       offsetof(struct sk_buff, headers_end) -
-		       offsetof(struct sk_buff, headers_start));
+	memset(&skb->headers, 0, sizeof(skb->headers));
 	if (encapsulating) {
 		skb->l4_hash = l4_hash;
 		skb->sw_hash = sw_hash;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6bdb0db3e825..fee9041aa402 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -801,11 +801,10 @@ struct sk_buff {
 	__u8			active_extensions;
 #endif
 
-	/* fields enclosed in headers_start/headers_end are copied
+	/* Fields enclosed in headers group are copied
 	 * using a single memcpy() in __copy_skb_header()
 	 */
-	/* private: */
-	__u32			headers_start[0];
+	struct_group(headers,
 	/* public: */
 
 /* if you move pkt_type around you also must adapt those constants */
@@ -922,8 +921,8 @@ struct sk_buff {
 	u64			kcov_handle;
 #endif
 
-	/* private: */
-	__u32			headers_end[0];
+	); /* end headers group */
+
 	/* public: */
 
 	/* These elements must be at the end, see alloc_skb() for details.  */
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f9311762cc47..fd5ce57ccce6 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -991,12 +991,10 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
 }
 EXPORT_SYMBOL(napi_consume_skb);
 
-/* Make sure a field is enclosed inside headers_start/headers_end section */
+/* Make sure a field is contained by headers group */
 #define CHECK_SKB_FIELD(field) \
-	BUILD_BUG_ON(offsetof(struct sk_buff, field) <		\
-		     offsetof(struct sk_buff, headers_start));	\
-	BUILD_BUG_ON(offsetof(struct sk_buff, field) >		\
-		     offsetof(struct sk_buff, headers_end));	\
+	BUILD_BUG_ON(offsetof(struct sk_buff, field) !=		\
+		     offsetof(struct sk_buff, headers.field));	\
 
 static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 {
@@ -1008,14 +1006,12 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 	__skb_ext_copy(new, old);
 	__nf_copy(new, old, false);
 
-	/* Note : this field could be in headers_start/headers_end section
+	/* Note : this field could be in the headers group.
 	 * It is not yet because we do not want to have a 16 bit hole
 	 */
 	new->queue_mapping = old->queue_mapping;
 
-	memcpy(&new->headers_start, &old->headers_start,
-	       offsetof(struct sk_buff, headers_end) -
-	       offsetof(struct sk_buff, headers_start));
+	memcpy(&new->headers, &old->headers, sizeof(new->headers));
 	CHECK_SKB_FIELD(protocol);
 	CHECK_SKB_FIELD(csum);
 	CHECK_SKB_FIELD(hash);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 08/63] bnxt_en: Use struct_group_attr() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (6 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group() Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 09/63] mwl8k: Use struct_group() " Kees Cook
                   ` (54 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Michael Chan, David S. Miller, Jakub Kicinski, netdev,
	Gustavo A . R . Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() around members queue_id, min_bw, max_bw, tsa, pri_lvl,
and bw_weight so they can be referenced together. This will allow memcpy()
and sizeof() to more easily reason about sizes, improve readability,
and avoid future warnings about writing beyond the end of queue_id.

"pahole" shows no size nor member offset changes to struct bnxt_cos2bw_cfg.
"objdump -d" shows no meaningful object code changes (i.e. only source
line number induced differences and optimizations).

Cc: Michael Chan <michael.chan@broadcom.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/lkml/CACKFLinDc6Y+P8eZ=450yA1nMC7swTURLtcdyiNR=9J6dfFyBg@mail.gmail.com
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728044517.GE35706@embeddedor
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c |  4 ++--
 drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h | 14 ++++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c
index 8a68df4d9e59..95c636f89329 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c
@@ -148,10 +148,10 @@ static int bnxt_hwrm_queue_cos2bw_qcfg(struct bnxt *bp, struct ieee_ets *ets)
 	}
 
 	data = &resp->queue_id0 + offsetof(struct bnxt_cos2bw_cfg, queue_id);
-	for (i = 0; i < bp->max_tc; i++, data += sizeof(cos2bw) - 4) {
+	for (i = 0; i < bp->max_tc; i++, data += sizeof(cos2bw.cfg)) {
 		int tc;
 
-		memcpy(&cos2bw.queue_id, data, sizeof(cos2bw) - 4);
+		memcpy(&cos2bw.cfg, data, sizeof(cos2bw.cfg));
 		if (i == 0)
 			cos2bw.queue_id = resp->queue_id0;
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h
index 6eed231de565..716742522161 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h
@@ -23,13 +23,15 @@ struct bnxt_dcb {
 
 struct bnxt_cos2bw_cfg {
 	u8			pad[3];
-	u8			queue_id;
-	__le32			min_bw;
-	__le32			max_bw;
+	struct_group_attr(cfg, __packed,
+		u8		queue_id;
+		__le32		min_bw;
+		__le32		max_bw;
 #define BW_VALUE_UNIT_PERCENT1_100		(0x1UL << 29)
-	u8			tsa;
-	u8			pri_lvl;
-	u8			bw_weight;
+		u8		tsa;
+		u8		pri_lvl;
+		u8		bw_weight;
+	);
 	u8			unused;
 };
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 09/63] mwl8k: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (7 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 08/63] bnxt_en: Use struct_group_attr() for memcpy() region Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 10/63] libertas: " Kees Cook
                   ` (53 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Lennert Buytenhek, Kalle Valo, David S. Miller,
	Jakub Kicinski, wengjianfeng, Lv Yunlong, Arnd Bergmann,
	Christophe JAILLET, Allen Pais, linux-wireless, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct mwl8k_cmd_set_key around members
key_material, tkip_tx_mic_key, and tkip_rx_mic_key so they can be
referenced together. This will allow memcpy() and sizeof() to more easily
reason about sizes, improve readability, and avoid future warnings about
writing beyond the end of key_material.

"pahole" shows no size nor member offset changes to struct
mwl8k_cmd_set_key. "objdump -d" shows no object code changes.

Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: wengjianfeng <wengjianfeng@yulong.com>
Cc: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Allen Pais <allen.lkml@gmail.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/marvell/mwl8k.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c
index 3bf6571f4149..a29277d5f9da 100644
--- a/drivers/net/wireless/marvell/mwl8k.c
+++ b/drivers/net/wireless/marvell/mwl8k.c
@@ -4225,9 +4225,11 @@ struct mwl8k_cmd_set_key {
 	__le32 key_info;
 	__le32 key_id;
 	__le16 key_len;
-	__u8 key_material[MAX_ENCR_KEY_LENGTH];
-	__u8 tkip_tx_mic_key[MIC_KEY_LENGTH];
-	__u8 tkip_rx_mic_key[MIC_KEY_LENGTH];
+	struct {
+			__u8 key_material[MAX_ENCR_KEY_LENGTH];
+			__u8 tkip_tx_mic_key[MIC_KEY_LENGTH];
+			__u8 tkip_rx_mic_key[MIC_KEY_LENGTH];
+	} tkip;
 	__le16 tkip_rsc_low;
 	__le32 tkip_rsc_high;
 	__le16 tkip_tsc_low;
@@ -4375,7 +4377,7 @@ static int mwl8k_cmd_encryption_set_key(struct ieee80211_hw *hw,
 		goto done;
 	}
 
-	memcpy(cmd->key_material, key->key, keymlen);
+	memcpy(&cmd->tkip, key->key, keymlen);
 	cmd->action = cpu_to_le32(action);
 
 	rc = mwl8k_post_pervif_cmd(hw, vif, &cmd->header);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 10/63] libertas: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (8 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 09/63] mwl8k: Use struct_group() " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 11/63] libertas_tf: " Kees Cook
                   ` (52 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Kalle Valo, David S. Miller, Jakub Kicinski,
	libertas-dev, linux-wireless, netdev, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct txpd around members tx_dest_addr_high
and tx_dest_addr_low so they can be referenced together. This will
allow memcpy() and sizeof() to more easily reason about sizes, improve
readability, and avoid future warnings about writing beyond the end
of queue_id.

"pahole" shows no size nor member offset changes to struct txpd.
"objdump -d" shows no object code changes.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: libertas-dev@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/marvell/libertas/host.h | 10 ++++++----
 drivers/net/wireless/marvell/libertas/tx.c   |  5 +++--
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas/host.h b/drivers/net/wireless/marvell/libertas/host.h
index dfa22468b14a..af96bdba3b2b 100644
--- a/drivers/net/wireless/marvell/libertas/host.h
+++ b/drivers/net/wireless/marvell/libertas/host.h
@@ -308,10 +308,12 @@ struct txpd {
 	__le32 tx_packet_location;
 	/* Tx packet length */
 	__le16 tx_packet_length;
-	/* First 2 byte of destination MAC address */
-	u8 tx_dest_addr_high[2];
-	/* Last 4 byte of destination MAC address */
-	u8 tx_dest_addr_low[4];
+	struct_group(tx_dest_addr,
+		/* First 2 byte of destination MAC address */
+		u8 tx_dest_addr_high[2];
+		/* Last 4 byte of destination MAC address */
+		u8 tx_dest_addr_low[4];
+	);
 	/* Pkt Priority */
 	u8 priority;
 	/* Pkt Trasnit Power control */
diff --git a/drivers/net/wireless/marvell/libertas/tx.c b/drivers/net/wireless/marvell/libertas/tx.c
index aeb481740df6..27304a98787d 100644
--- a/drivers/net/wireless/marvell/libertas/tx.c
+++ b/drivers/net/wireless/marvell/libertas/tx.c
@@ -113,6 +113,7 @@ netdev_tx_t lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	p802x_hdr = skb->data;
 	pkt_len = skb->len;
 
+	BUILD_BUG_ON(sizeof(txpd->tx_dest_addr) != ETH_ALEN);
 	if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
 		struct tx_radiotap_hdr *rtap_hdr = (void *)skb->data;
 
@@ -124,10 +125,10 @@ netdev_tx_t lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		pkt_len -= sizeof(*rtap_hdr);
 
 		/* copy destination address from 802.11 header */
-		memcpy(txpd->tx_dest_addr_high, p802x_hdr + 4, ETH_ALEN);
+		memcpy(&txpd->tx_dest_addr, p802x_hdr + 4, ETH_ALEN);
 	} else {
 		/* copy destination address from 802.3 header */
-		memcpy(txpd->tx_dest_addr_high, p802x_hdr, ETH_ALEN);
+		memcpy(&txpd->tx_dest_addr, p802x_hdr, ETH_ALEN);
 	}
 
 	txpd->tx_packet_length = cpu_to_le16(pkt_len);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 11/63] libertas_tf: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (9 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 10/63] libertas: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 12/63] thermal: intel: int340x_thermal: " Kees Cook
                   ` (51 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Kalle Valo, David S. Miller, Jakub Kicinski,
	Lee Jones, YueHaibing, linux-wireless, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field array bounds checking for memcpy(), memmove(), and memset(),
avoid intentionally writing across neighboring fields.

Use struct_group() in struct txpd around members tx_dest_addr_high
and tx_dest_addr_low so they can be referenced together. This will
allow memcpy() and sizeof() to more easily reason about sizes, improve
readability, and avoid future warnings about writing beyond the end
of tx_dest_addr_high.

"pahole" shows no size nor member offset changes to struct txpd.
"objdump -d" shows no object code changes.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/marvell/libertas_tf/libertas_tf.h | 10 ++++++----
 drivers/net/wireless/marvell/libertas_tf/main.c        |  3 ++-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h b/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h
index 5d726545d987..b2af2ddb6bc4 100644
--- a/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h
+++ b/drivers/net/wireless/marvell/libertas_tf/libertas_tf.h
@@ -268,10 +268,12 @@ struct txpd {
 	__le32 tx_packet_location;
 	/* Tx packet length */
 	__le16 tx_packet_length;
-	/* First 2 byte of destination MAC address */
-	u8 tx_dest_addr_high[2];
-	/* Last 4 byte of destination MAC address */
-	u8 tx_dest_addr_low[4];
+	struct_group(tx_dest_addr,
+		/* First 2 byte of destination MAC address */
+		u8 tx_dest_addr_high[2];
+		/* Last 4 byte of destination MAC address */
+		u8 tx_dest_addr_low[4];
+	);
 	/* Pkt Priority */
 	u8 priority;
 	/* Pkt Trasnit Power control */
diff --git a/drivers/net/wireless/marvell/libertas_tf/main.c b/drivers/net/wireless/marvell/libertas_tf/main.c
index 71492211904b..02a1e1f547d8 100644
--- a/drivers/net/wireless/marvell/libertas_tf/main.c
+++ b/drivers/net/wireless/marvell/libertas_tf/main.c
@@ -232,7 +232,8 @@ static void lbtf_tx_work(struct work_struct *work)
 			     ieee80211_get_tx_rate(priv->hw, info)->hw_value);
 
 	/* copy destination address from 802.11 header */
-	memcpy(txpd->tx_dest_addr_high, skb->data + sizeof(struct txpd) + 4,
+	BUILD_BUG_ON(sizeof(txpd->tx_dest_addr) != ETH_ALEN);
+	memcpy(&txpd->tx_dest_addr, skb->data + sizeof(struct txpd) + 4,
 		ETH_ALEN);
 	txpd->tx_packet_length = cpu_to_le16(len);
 	txpd->tx_packet_location = cpu_to_le32(sizeof(struct txpd));
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 12/63] thermal: intel: int340x_thermal: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (10 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 11/63] libertas_tf: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-11-23 13:19   ` Rafael J. Wysocki
  2021-08-18  6:04 ` [PATCH v2 13/63] iommu/amd: " Kees Cook
                   ` (50 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Zhang Rui, Daniel Lezcano, Amit Kucheria, linux-pm,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), avoid intentionally writing across
neighboring fields.

Use struct_group() in struct art around members weight, and ac[0-9]_max,
so they can be referenced together. This will allow memcpy() and sizeof()
to more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of weight.

"pahole" shows no size nor member offset changes to struct art.
"objdump -d" shows no meaningful object code changes (i.e. only source
line number induced differences).

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amitk@kernel.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 .../intel/int340x_thermal/acpi_thermal_rel.c  |  5 +-
 .../intel/int340x_thermal/acpi_thermal_rel.h  | 48 ++++++++++---------
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
index a478cff8162a..e90690a234c4 100644
--- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
+++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
@@ -250,8 +250,9 @@ static int fill_art(char __user *ubuf)
 		get_single_name(arts[i].source, art_user[i].source_device);
 		get_single_name(arts[i].target, art_user[i].target_device);
 		/* copy the rest int data in addition to source and target */
-		memcpy(&art_user[i].weight, &arts[i].weight,
-			sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
+		BUILD_BUG_ON(sizeof(art_user[i].data) !=
+			     sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
+		memcpy(&art_user[i].data, &arts[i].data, sizeof(art_user[i].data));
 	}
 
 	if (copy_to_user(ubuf, art_user, art_len))
diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
index 58822575fd54..78d942477035 100644
--- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
+++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
@@ -17,17 +17,19 @@
 struct art {
 	acpi_handle source;
 	acpi_handle target;
-	u64 weight;
-	u64 ac0_max;
-	u64 ac1_max;
-	u64 ac2_max;
-	u64 ac3_max;
-	u64 ac4_max;
-	u64 ac5_max;
-	u64 ac6_max;
-	u64 ac7_max;
-	u64 ac8_max;
-	u64 ac9_max;
+	struct_group(data,
+		u64 weight;
+		u64 ac0_max;
+		u64 ac1_max;
+		u64 ac2_max;
+		u64 ac3_max;
+		u64 ac4_max;
+		u64 ac5_max;
+		u64 ac6_max;
+		u64 ac7_max;
+		u64 ac8_max;
+		u64 ac9_max;
+	);
 } __packed;
 
 struct trt {
@@ -47,17 +49,19 @@ union art_object {
 	struct {
 		char source_device[8]; /* ACPI single name */
 		char target_device[8]; /* ACPI single name */
-		u64 weight;
-		u64 ac0_max_level;
-		u64 ac1_max_level;
-		u64 ac2_max_level;
-		u64 ac3_max_level;
-		u64 ac4_max_level;
-		u64 ac5_max_level;
-		u64 ac6_max_level;
-		u64 ac7_max_level;
-		u64 ac8_max_level;
-		u64 ac9_max_level;
+		struct_group(data,
+			u64 weight;
+			u64 ac0_max_level;
+			u64 ac1_max_level;
+			u64 ac2_max_level;
+			u64 ac3_max_level;
+			u64 ac4_max_level;
+			u64 ac5_max_level;
+			u64 ac6_max_level;
+			u64 ac7_max_level;
+			u64 ac8_max_level;
+			u64 ac9_max_level;
+		);
 	};
 	u64 __data[ACPI_NR_ART_ELEMENTS];
 };
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 13/63] iommu/amd: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (11 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 12/63] thermal: intel: int340x_thermal: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18 11:34   ` Joerg Roedel
  2021-08-18  6:04 ` [PATCH v2 14/63] cxgb3: " Kees Cook
                   ` (49 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Joerg Roedel, Will Deacon, iommu, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct ivhd_entry around members ext and hidh, so
they can be referenced together. This will allow memcpy() and sizeof()
to more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of ext.

"pahole" shows no size nor member offset changes to struct ivhd_entry.
"objdump -d" shows no object code changes.

Cc: Joerg Roedel <joro@8bytes.org>
Cc: Will Deacon <will@kernel.org>
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/iommu/amd/init.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index bdcf167b4afe..70506d6175e9 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -121,8 +121,10 @@ struct ivhd_entry {
 	u8 type;
 	u16 devid;
 	u8 flags;
-	u32 ext;
-	u32 hidh;
+	struct_group(ext_hid,
+		u32 ext;
+		u32 hidh;
+	);
 	u64 cid;
 	u8 uidf;
 	u8 uidl;
@@ -1377,7 +1379,8 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu,
 				break;
 			}
 
-			memcpy(hid, (u8 *)(&e->ext), ACPIHID_HID_LEN - 1);
+			BUILD_BUG_ON(sizeof(e->ext_hid) != ACPIHID_HID_LEN - 1);
+			memcpy(hid, &e->ext_hid, ACPIHID_HID_LEN - 1);
 			hid[ACPIHID_HID_LEN - 1] = '\0';
 
 			if (!(*hid)) {
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 14/63] cxgb3: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (12 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 13/63] iommu/amd: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 15/63] intersil: " Kees Cook
                   ` (48 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Raju Rangoju, David S. Miller, Jakub Kicinski, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct rss_hdr around members imm_data and intr_gen,
so they can be referenced together. This will allow memcpy() and sizeof()
to more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of imm_data.

"pahole" shows no size nor member offset changes to struct rss_hdr.
"objdump -d" shows no object code changes.

Cc: Raju Rangoju <rajur@chelsio.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/chelsio/cxgb3/sge.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb3/sge.c b/drivers/net/ethernet/chelsio/cxgb3/sge.c
index cb5c79c43bc9..1ab1bd86a3a6 100644
--- a/drivers/net/ethernet/chelsio/cxgb3/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c
@@ -126,8 +126,10 @@ struct rsp_desc {		/* response queue descriptor */
 	struct rss_header rss_hdr;
 	__be32 flags;
 	__be32 len_cq;
-	u8 imm_data[47];
-	u8 intr_gen;
+	struct_group(immediate,
+		u8 imm_data[47];
+		u8 intr_gen;
+	);
 };
 
 /*
@@ -929,7 +931,8 @@ static inline struct sk_buff *get_imm_packet(const struct rsp_desc *resp)
 
 	if (skb) {
 		__skb_put(skb, IMMED_PKT_SIZE);
-		skb_copy_to_linear_data(skb, resp->imm_data, IMMED_PKT_SIZE);
+		BUILD_BUG_ON(IMMED_PKT_SIZE != sizeof(resp->immediate));
+		skb_copy_to_linear_data(skb, &resp->immediate, IMMED_PKT_SIZE);
 	}
 	return skb;
 }
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 15/63] intersil: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (13 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 14/63] cxgb3: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 16/63] cxgb4: " Kees Cook
                   ` (47 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Jouni Malinen, Kalle Valo, David S. Miller,
	Jakub Kicinski, Lee Jones, Allen Pais, Romain Perier,
	Arnd Bergmann, Vaibhav Gupta, Cong Wang,
	Sebastian Andrzej Siewior, linux-wireless, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct hfa384x_tx_frame around members
frame_control, duration_id, addr1, addr2, addr3, and seq_ctrl, so they
can be referenced together. This will allow memcpy() and sizeof() to
more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of frame_control.

"pahole" shows no size nor member offset changes to struct
hfa384x_tx_frame. "objdump -d" shows no object code changes.

Cc: Jouni Malinen <j@w1.fi>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Allen Pais <allen.lkml@gmail.com>
Cc: Romain Perier <romain.perier@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/intersil/hostap/hostap_hw.c   |  5 +++--
 drivers/net/wireless/intersil/hostap/hostap_wlan.h | 14 ++++++++------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/intersil/hostap/hostap_hw.c b/drivers/net/wireless/intersil/hostap/hostap_hw.c
index 9a19046217df..cea8a9ddc4da 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_hw.c
+++ b/drivers/net/wireless/intersil/hostap/hostap_hw.c
@@ -1812,8 +1812,9 @@ static int prism2_tx_80211(struct sk_buff *skb, struct net_device *dev)
 	memset(&txdesc, 0, sizeof(txdesc));
 
 	/* skb->data starts with txdesc->frame_control */
-	hdr_len = 24;
-	skb_copy_from_linear_data(skb, &txdesc.frame_control, hdr_len);
+	hdr_len = sizeof(txdesc.frame);
+	BUILD_BUG_ON(hdr_len != 24);
+	skb_copy_from_linear_data(skb, &txdesc.frame, hdr_len);
 	if (ieee80211_is_data(txdesc.frame_control) &&
 	    ieee80211_has_a4(txdesc.frame_control) &&
 	    skb->len >= 30) {
diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h
index dd2603d9b5d3..174735a137c5 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h
+++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h
@@ -115,12 +115,14 @@ struct hfa384x_tx_frame {
 	__le16 tx_control; /* HFA384X_TX_CTRL_ flags */
 
 	/* 802.11 */
-	__le16 frame_control; /* parts not used */
-	__le16 duration_id;
-	u8 addr1[ETH_ALEN];
-	u8 addr2[ETH_ALEN]; /* filled by firmware */
-	u8 addr3[ETH_ALEN];
-	__le16 seq_ctrl; /* filled by firmware */
+	struct_group(frame,
+		__le16 frame_control; /* parts not used */
+		__le16 duration_id;
+		u8 addr1[ETH_ALEN];
+		u8 addr2[ETH_ALEN]; /* filled by firmware */
+		u8 addr3[ETH_ALEN];
+		__le16 seq_ctrl; /* filled by firmware */
+	);
 	u8 addr4[ETH_ALEN];
 	__le16 data_len;
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 16/63] cxgb4: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (14 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 15/63] intersil: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 17/63] bnx2x: " Kees Cook
                   ` (46 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Raju Rangoju, David S. Miller, Jakub Kicinski, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct fw_eth_tx_pkt_vm_wr around members ethmacdst,
ethmacsrc, ethtype, and vlantci, so they can be referenced together. This
will allow memcpy() and sizeof() to more easily reason about sizes,
improve readability, and avoid future warnings about writing beyond the
end of ethmacdst.

"pahole" shows no size nor member offset changes to struct
fw_eth_tx_pkt_vm_wr. "objdump -d" shows no object code changes.

Cc: Raju Rangoju <rajur@chelsio.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/chelsio/cxgb4/sge.c      |  8 +++++---
 drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h | 10 ++++++----
 drivers/net/ethernet/chelsio/cxgb4vf/sge.c    |  7 ++-----
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 6a099cb34b12..9080b2c5ffe8 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -1842,8 +1842,10 @@ static netdev_tx_t cxgb4_vf_eth_xmit(struct sk_buff *skb,
 	 * (including the VLAN tag) into the header so we reject anything
 	 * smaller than that ...
 	 */
-	fw_hdr_copy_len = sizeof(wr->ethmacdst) + sizeof(wr->ethmacsrc) +
-			  sizeof(wr->ethtype) + sizeof(wr->vlantci);
+	BUILD_BUG_ON(sizeof(wr->firmware) !=
+		     (sizeof(wr->ethmacdst) + sizeof(wr->ethmacsrc) +
+		      sizeof(wr->ethtype) + sizeof(wr->vlantci)));
+	fw_hdr_copy_len = sizeof(wr->firmware);
 	ret = cxgb4_validate_skb(skb, dev, fw_hdr_copy_len);
 	if (ret)
 		goto out_free;
@@ -1924,7 +1926,7 @@ static netdev_tx_t cxgb4_vf_eth_xmit(struct sk_buff *skb,
 	wr->equiq_to_len16 = cpu_to_be32(wr_mid);
 	wr->r3[0] = cpu_to_be32(0);
 	wr->r3[1] = cpu_to_be32(0);
-	skb_copy_from_linear_data(skb, (void *)wr->ethmacdst, fw_hdr_copy_len);
+	skb_copy_from_linear_data(skb, &wr->firmware, fw_hdr_copy_len);
 	end = (u64 *)wr + flits;
 
 	/* If this is a Large Send Offload packet we'll put in an LSO CPL
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h b/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
index 0a326c054707..2419459a0b85 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
@@ -794,10 +794,12 @@ struct fw_eth_tx_pkt_vm_wr {
 	__be32 op_immdlen;
 	__be32 equiq_to_len16;
 	__be32 r3[2];
-	u8 ethmacdst[6];
-	u8 ethmacsrc[6];
-	__be16 ethtype;
-	__be16 vlantci;
+	struct_group(firmware,
+		u8 ethmacdst[ETH_ALEN];
+		u8 ethmacsrc[ETH_ALEN];
+		__be16 ethtype;
+		__be16 vlantci;
+	);
 };
 
 #define FW_CMD_MAX_TIMEOUT 10000
diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/sge.c b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
index 7bc80eeb2c21..671ca93e64ab 100644
--- a/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
@@ -1167,10 +1167,7 @@ netdev_tx_t t4vf_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct cpl_tx_pkt_core *cpl;
 	const struct skb_shared_info *ssi;
 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
-	const size_t fw_hdr_copy_len = (sizeof(wr->ethmacdst) +
-					sizeof(wr->ethmacsrc) +
-					sizeof(wr->ethtype) +
-					sizeof(wr->vlantci));
+	const size_t fw_hdr_copy_len = sizeof(wr->firmware);
 
 	/*
 	 * The chip minimum packet length is 10 octets but the firmware
@@ -1267,7 +1264,7 @@ netdev_tx_t t4vf_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 	wr->equiq_to_len16 = cpu_to_be32(wr_mid);
 	wr->r3[0] = cpu_to_be32(0);
 	wr->r3[1] = cpu_to_be32(0);
-	skb_copy_from_linear_data(skb, (void *)wr->ethmacdst, fw_hdr_copy_len);
+	skb_copy_from_linear_data(skb, &wr->firmware, fw_hdr_copy_len);
 	end = (u64 *)wr + flits;
 
 	/*
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 17/63] bnx2x: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (15 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 16/63] cxgb4: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 18/63] drm/amd/pm: " Kees Cook
                   ` (45 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Ariel Elior, Sudarsana Kalluru, GR-everest-linux-l2,
	David S. Miller, Jakub Kicinski, netdev, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct nig_stats around members egress_mac_pkt0_lo,
egress_mac_pkt0_hi, egress_mac_pkt1_lo, and egress_mac_pkt1_hi (and the
respective members in struct bnx2x_eth_stats), so they can be referenced
together. This will allow memcpy() and sizeof() to more easily reason
about sizes, improve readability, and avoid future warnings about writing
beyond the end of struct bnx2x_eth_stats's rx_stat_ifhcinbadoctets_hi.

"pahole" shows no size nor member offset changes to either struct.
"objdump -d" shows no meaningful object code changes (i.e. only source
line number induced differences and optimizations).

Additionally adds BUILD_BUG_ON() to compare the separate struct group
sizes.

Cc: Ariel Elior <aelior@marvell.com>
Cc: Sudarsana Kalluru <skalluru@marvell.com>
Cc: GR-everest-linux-l2@marvell.com
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c |  7 ++++---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h | 14 ++++++++++----
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c
index 0b193edb73b8..2bb133ae61c3 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c
@@ -849,7 +849,8 @@ static int bnx2x_hw_stats_update(struct bnx2x *bp)
 
 	memcpy(old, new, sizeof(struct nig_stats));
 
-	memcpy(&(estats->rx_stat_ifhcinbadoctets_hi), &(pstats->mac_stx[1]),
+	BUILD_BUG_ON(sizeof(estats->shared) != sizeof(pstats->mac_stx[1]));
+	memcpy(&(estats->shared), &(pstats->mac_stx[1]),
 	       sizeof(struct mac_stx));
 	estats->brb_drop_hi = pstats->brb_drop_hi;
 	estats->brb_drop_lo = pstats->brb_drop_lo;
@@ -1634,9 +1635,9 @@ void bnx2x_stats_init(struct bnx2x *bp)
 			REG_RD(bp, NIG_REG_STAT0_BRB_TRUNCATE + port*0x38);
 	if (!CHIP_IS_E3(bp)) {
 		REG_RD_DMAE(bp, NIG_REG_STAT0_EGRESS_MAC_PKT0 + port*0x50,
-			    &(bp->port.old_nig_stats.egress_mac_pkt0_lo), 2);
+			    &(bp->port.old_nig_stats.egress_mac_pkt0), 2);
 		REG_RD_DMAE(bp, NIG_REG_STAT0_EGRESS_MAC_PKT1 + port*0x50,
-			    &(bp->port.old_nig_stats.egress_mac_pkt1_lo), 2);
+			    &(bp->port.old_nig_stats.egress_mac_pkt1), 2);
 	}
 
 	/* Prepare statistics ramrod data */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h
index d55e63692cf3..ae93c078707b 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h
@@ -36,10 +36,14 @@ struct nig_stats {
 	u32 pbf_octets;
 	u32 pbf_packet;
 	u32 safc_inp;
-	u32 egress_mac_pkt0_lo;
-	u32 egress_mac_pkt0_hi;
-	u32 egress_mac_pkt1_lo;
-	u32 egress_mac_pkt1_hi;
+	struct_group(egress_mac_pkt0,
+		u32 egress_mac_pkt0_lo;
+		u32 egress_mac_pkt0_hi;
+	);
+	struct_group(egress_mac_pkt1,
+		u32 egress_mac_pkt1_lo;
+		u32 egress_mac_pkt1_hi;
+	);
 };
 
 enum bnx2x_stats_event {
@@ -83,6 +87,7 @@ struct bnx2x_eth_stats {
 	u32 no_buff_discard_hi;
 	u32 no_buff_discard_lo;
 
+	struct_group(shared,
 	u32 rx_stat_ifhcinbadoctets_hi;
 	u32 rx_stat_ifhcinbadoctets_lo;
 	u32 tx_stat_ifhcoutbadoctets_hi;
@@ -159,6 +164,7 @@ struct bnx2x_eth_stats {
 	u32 tx_stat_dot3statsinternalmactransmiterrors_lo;
 	u32 tx_stat_bmac_ufl_hi;
 	u32 tx_stat_bmac_ufl_lo;
+	);
 
 	u32 pause_frames_received_hi;
 	u32 pause_frames_received_lo;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 18/63] drm/amd/pm: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (16 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 17/63] bnx2x: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18 11:42   ` Lazar, Lijo
  2021-08-18  6:04 ` [PATCH v2 19/63] staging: wlan-ng: " Kees Cook
                   ` (44 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Christian König, Pan, Xinhui, David Airlie,
	Daniel Vetter, Hawking Zhang, Feifei Xu, Lijo Lazar, Likun Gao,
	Jiawei Gu, Evan Quan, amd-gfx, dri-devel, Alex Deucher,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in structs:
	struct atom_smc_dpm_info_v4_5
	struct atom_smc_dpm_info_v4_6
	struct atom_smc_dpm_info_v4_7
	struct atom_smc_dpm_info_v4_10
	PPTable_t
so the grouped members can be referenced together. This will allow
memcpy() and sizeof() to more easily reason about sizes, improve
readability, and avoid future warnings about writing beyond the end of
the first member.

"pahole" shows no size nor member offset changes to any structs.
"objdump -d" shows no object code changes.

Cc: "Christian König" <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Feifei Xu <Feifei.Xu@amd.com>
Cc: Lijo Lazar <lijo.lazar@amd.com>
Cc: Likun Gao <Likun.Gao@amd.com>
Cc: Jiawei Gu <Jiawei.Gu@amd.com>
Cc: Evan Quan <evan.quan@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/lkml/CADnq5_Npb8uYvd+R4UHgf-w8-cQj3JoODjviJR_Y9w9wqJ71mQ@mail.gmail.com
---
 drivers/gpu/drm/amd/include/atomfirmware.h           |  9 ++++++++-
 .../gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h    |  3 ++-
 drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h  |  3 ++-
 .../gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h   |  3 ++-
 drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c    |  6 +++---
 drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c      | 12 ++++++++----
 drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c   |  6 +++---
 7 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/amd/include/atomfirmware.h b/drivers/gpu/drm/amd/include/atomfirmware.h
index 44955458fe38..7bf3edf15410 100644
--- a/drivers/gpu/drm/amd/include/atomfirmware.h
+++ b/drivers/gpu/drm/amd/include/atomfirmware.h
@@ -2081,6 +2081,7 @@ struct atom_smc_dpm_info_v4_5
 {
   struct   atom_common_table_header  table_header;
     // SECTION: BOARD PARAMETERS
+  struct_group(dpm_info,
     // I2C Control
   struct smudpm_i2c_controller_config_v2  I2cControllers[8];
 
@@ -2159,7 +2160,7 @@ struct atom_smc_dpm_info_v4_5
   uint32_t MvddRatio; // This is used for MVDD Vid workaround. It has 16 fractional bits (Q16.16)
   
   uint32_t     BoardReserved[9];
-
+  );
 };
 
 struct atom_smc_dpm_info_v4_6
@@ -2168,6 +2169,7 @@ struct atom_smc_dpm_info_v4_6
   // section: board parameters
   uint32_t     i2c_padding[3];   // old i2c control are moved to new area
 
+  struct_group(dpm_info,
   uint16_t     maxvoltagestepgfx; // in mv(q2) max voltage step that smu will request. multiple steps are taken if voltage change exceeds this value.
   uint16_t     maxvoltagestepsoc; // in mv(q2) max voltage step that smu will request. multiple steps are taken if voltage change exceeds this value.
 
@@ -2246,12 +2248,14 @@ struct atom_smc_dpm_info_v4_6
 
   // reserved
   uint32_t   boardreserved[10];
+  );
 };
 
 struct atom_smc_dpm_info_v4_7
 {
   struct   atom_common_table_header  table_header;
     // SECTION: BOARD PARAMETERS
+  struct_group(dpm_info,
     // I2C Control
   struct smudpm_i2c_controller_config_v2  I2cControllers[8];
 
@@ -2348,6 +2352,7 @@ struct atom_smc_dpm_info_v4_7
   uint8_t      Padding8_Psi2;
 
   uint32_t     BoardReserved[5];
+  );
 };
 
 struct smudpm_i2c_controller_config_v3
@@ -2478,6 +2483,7 @@ struct atom_smc_dpm_info_v4_10
   struct   atom_common_table_header  table_header;
 
   // SECTION: BOARD PARAMETERS
+  struct_group(dpm_info,
   // Telemetry Settings
   uint16_t GfxMaxCurrent; // in Amps
   uint8_t   GfxOffset;     // in Amps
@@ -2524,6 +2530,7 @@ struct atom_smc_dpm_info_v4_10
   uint16_t spare5;
 
   uint32_t reserved[16];
+  );
 };
 
 /* 
diff --git a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
index 43d43d6addc0..8093a98800c3 100644
--- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
+++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
@@ -643,6 +643,7 @@ typedef struct {
   // SECTION: BOARD PARAMETERS
 
   // SVI2 Board Parameters
+  struct_group(v4_6,
   uint16_t     MaxVoltageStepGfx; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
   uint16_t     MaxVoltageStepSoc; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
 
@@ -728,10 +729,10 @@ typedef struct {
   uint32_t     BoardVoltageCoeffB;    // decode by /1000
 
   uint32_t     BoardReserved[7];
+  );
 
   // Padding for MMHUB - do not modify this
   uint32_t     MmHubPadding[8]; // SMU internal use
-
 } PPTable_t;
 
 typedef struct {
diff --git a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
index 04752ade1016..0b4e6e907e95 100644
--- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
+++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
@@ -725,6 +725,7 @@ typedef struct {
   uint32_t     Reserved[8];
 
   // SECTION: BOARD PARAMETERS
+  struct_group(v4,
   // I2C Control
   I2cControllerConfig_t  I2cControllers[NUM_I2C_CONTROLLERS];     
 
@@ -809,10 +810,10 @@ typedef struct {
   uint8_t      Padding8_Loadline;
 
   uint32_t     BoardReserved[8];
+  );
 
   // Padding for MMHUB - do not modify this
   uint32_t     MmHubPadding[8]; // SMU internal use
-
 } PPTable_t;
 
 typedef struct {
diff --git a/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h b/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
index a017983ff1fa..5056d3728da8 100644
--- a/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
+++ b/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
@@ -390,6 +390,7 @@ typedef struct {
   uint32_t spare3[14];
 
   // SECTION: BOARD PARAMETERS
+  struct_group(v4_10,
   // Telemetry Settings
   uint16_t GfxMaxCurrent; // in Amps
   int8_t   GfxOffset;     // in Amps
@@ -444,7 +445,7 @@ typedef struct {
 
   //reserved
   uint32_t reserved[14];
-
+  );
 } PPTable_t;
 
 typedef struct {
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
index 8ab58781ae13..341adf209240 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
@@ -463,11 +463,11 @@ static int arcturus_append_powerplay_table(struct smu_context *smu)
 			smc_dpm_table->table_header.format_revision,
 			smc_dpm_table->table_header.content_revision);
 
+	BUILD_BUG_ON(sizeof(smc_pptable->v4_6) != sizeof(smc_dpm_table->dpm_info));
 	if ((smc_dpm_table->table_header.format_revision == 4) &&
 	    (smc_dpm_table->table_header.content_revision == 6))
-		memcpy(&smc_pptable->MaxVoltageStepGfx,
-		       &smc_dpm_table->maxvoltagestepgfx,
-		       sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_6, maxvoltagestepgfx));
+		memcpy(&smc_pptable->v4_6, &smc_dpm_table->dpm_info,
+		       sizeof(smc_dpm_table->dpm_info));
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
index 2e5d3669652b..e8b6e25a7815 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
@@ -431,16 +431,20 @@ static int navi10_append_powerplay_table(struct smu_context *smu)
 
 	switch (smc_dpm_table->table_header.content_revision) {
 	case 5: /* nv10 and nv14 */
-		memcpy(smc_pptable->I2cControllers, smc_dpm_table->I2cControllers,
-			sizeof(*smc_dpm_table) - sizeof(smc_dpm_table->table_header));
+		BUILD_BUG_ON(sizeof(smc_pptable->v4) !=
+			     sizeof(smc_dpm_table->dpm_info));
+		memcpy(&smc_pptable->v4, &smc_dpm_table->dpm_info,
+		       sizeof(smc_dpm_table->dpm_info));
 		break;
 	case 7: /* nv12 */
 		ret = amdgpu_atombios_get_data_table(adev, index, NULL, NULL, NULL,
 					      (uint8_t **)&smc_dpm_table_v4_7);
 		if (ret)
 			return ret;
-		memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
-			sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));
+		BUILD_BUG_ON(sizeof(smc_pptable->v4) !=
+			     sizeof(smc_dpm_table_v4_7->dpm_info));
+		memcpy(&smc_pptable->v4, &smc_dpm_table_v4_7->dpm_info,
+		       sizeof(smc_dpm_table_v4_7->dpm_info));
 		break;
 	default:
 		dev_err(smu->adev->dev, "smc_dpm_info with unsupported content revision %d!\n",
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
index c8eefacfdd37..492ba37bc514 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
@@ -407,11 +407,11 @@ static int aldebaran_append_powerplay_table(struct smu_context *smu)
 			smc_dpm_table->table_header.format_revision,
 			smc_dpm_table->table_header.content_revision);
 
+	BUILD_BUG_ON(sizeof(smc_pptable->v4_10) != sizeof(smc_dpm_table->dpm_info));
 	if ((smc_dpm_table->table_header.format_revision == 4) &&
 	    (smc_dpm_table->table_header.content_revision == 10))
-		memcpy(&smc_pptable->GfxMaxCurrent,
-		       &smc_dpm_table->GfxMaxCurrent,
-		       sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_10, GfxMaxCurrent));
+		memcpy(&smc_pptable->v4_10, &smc_dpm_table->dpm_info,
+		       sizeof(smc_dpm_table->dpm_info));
 	return 0;
 }
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 19/63] staging: wlan-ng: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (17 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 18/63] drm/amd/pm: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 20/63] drm/mga/mga_ioc32: " Kees Cook
                   ` (43 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Greg Kroah-Hartman, Rustam Kovhaev,
	syzbot+22794221ab96b0bab53a, Allen Pais, Romain Perier,
	linux-staging, Gustavo A. R. Silva, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct hfa384x_tx_frame around members
frame_control, duration_id, address[1-4], and sequence_control, so they
can be referenced together. This will allow memcpy() and sizeof() to
more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of frame_control.

"pahole" shows no size nor member offset changes to struct
hfa384x_tx_frame. "objdump -d" shows no meaningful object code changes
(i.e. only source line number induced differences.)

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rustam Kovhaev <rkovhaev@gmail.com>
Cc: syzbot+22794221ab96b0bab53a@syzkaller.appspotmail.com
Cc: Allen Pais <apais@linux.microsoft.com>
Cc: Romain Perier <romain.perier@gmail.com>
Cc: linux-staging@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/lkml/YQDvC4CghCazix4w@kroah.com
---
 drivers/staging/wlan-ng/hfa384x.h     | 16 +++++++++-------
 drivers/staging/wlan-ng/hfa384x_usb.c |  4 +++-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/wlan-ng/hfa384x.h b/drivers/staging/wlan-ng/hfa384x.h
index 88e894dd3568..87eb87e3beab 100644
--- a/drivers/staging/wlan-ng/hfa384x.h
+++ b/drivers/staging/wlan-ng/hfa384x.h
@@ -476,13 +476,15 @@ struct hfa384x_tx_frame {
 
 	/*-- 802.11 Header Information --*/
 
-	u16 frame_control;
-	u16 duration_id;
-	u8 address1[6];
-	u8 address2[6];
-	u8 address3[6];
-	u16 sequence_control;
-	u8 address4[6];
+	struct_group(p80211,
+		u16 frame_control;
+		u16 duration_id;
+		u8 address1[6];
+		u8 address2[6];
+		u8 address3[6];
+		u16 sequence_control;
+		u8 address4[6];
+	);
 	__le16 data_len;		/* little endian format */
 
 	/*-- 802.3 Header Information --*/
diff --git a/drivers/staging/wlan-ng/hfa384x_usb.c b/drivers/staging/wlan-ng/hfa384x_usb.c
index f2a0e16b0318..38aaae7a2d69 100644
--- a/drivers/staging/wlan-ng/hfa384x_usb.c
+++ b/drivers/staging/wlan-ng/hfa384x_usb.c
@@ -2516,7 +2516,9 @@ int hfa384x_drvr_txframe(struct hfa384x *hw, struct sk_buff *skb,
 	cpu_to_le16s(&hw->txbuff.txfrm.desc.tx_control);
 
 	/* copy the header over to the txdesc */
-	memcpy(&hw->txbuff.txfrm.desc.frame_control, p80211_hdr,
+	BUILD_BUG_ON(sizeof(hw->txbuff.txfrm.desc.p80211) !=
+		     sizeof(union p80211_hdr));
+	memcpy(&hw->txbuff.txfrm.desc.p80211, p80211_hdr,
 	       sizeof(union p80211_hdr));
 
 	/* if we're using host WEP, increase size by IV+ICV */
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 20/63] drm/mga/mga_ioc32: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (18 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 19/63] staging: wlan-ng: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 21/63] net/mlx5e: " Kees Cook
                   ` (42 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, David Airlie, Lee Jones, dri-devel, Daniel Vetter,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct drm32_mga_init around members chipset, sgram,
maccess, fb_cpp, front_offset, front_pitch, back_offset, back_pitch,
depth_cpp, depth_offset, depth_pitch, texture_offset, and texture_size,
so they can be referenced together. This will allow memcpy() and sizeof()
to more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of chipset.

"pahole" shows no size nor member offset changes to struct drm32_mga_init.
"objdump -d" shows no meaningful object code changes (i.e. only source
line number induced differences and optimizations).

Note that since this is a UAPI header, __struct_group() is used
directly.

Cc: David Airlie <airlied@linux.ie>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local
---
 drivers/gpu/drm/mga/mga_ioc32.c | 27 ++++++++++++++-------------
 include/uapi/drm/mga_drm.h      | 22 ++++++++++++----------
 2 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/mga/mga_ioc32.c b/drivers/gpu/drm/mga/mga_ioc32.c
index 4fd4de16cd32..894472921c30 100644
--- a/drivers/gpu/drm/mga/mga_ioc32.c
+++ b/drivers/gpu/drm/mga/mga_ioc32.c
@@ -38,16 +38,18 @@
 typedef struct drm32_mga_init {
 	int func;
 	u32 sarea_priv_offset;
-	int chipset;
-	int sgram;
-	unsigned int maccess;
-	unsigned int fb_cpp;
-	unsigned int front_offset, front_pitch;
-	unsigned int back_offset, back_pitch;
-	unsigned int depth_cpp;
-	unsigned int depth_offset, depth_pitch;
-	unsigned int texture_offset[MGA_NR_TEX_HEAPS];
-	unsigned int texture_size[MGA_NR_TEX_HEAPS];
+	struct_group(always32bit,
+		int chipset;
+		int sgram;
+		unsigned int maccess;
+		unsigned int fb_cpp;
+		unsigned int front_offset, front_pitch;
+		unsigned int back_offset, back_pitch;
+		unsigned int depth_cpp;
+		unsigned int depth_offset, depth_pitch;
+		unsigned int texture_offset[MGA_NR_TEX_HEAPS];
+		unsigned int texture_size[MGA_NR_TEX_HEAPS];
+	);
 	u32 fb_offset;
 	u32 mmio_offset;
 	u32 status_offset;
@@ -67,9 +69,8 @@ static int compat_mga_init(struct file *file, unsigned int cmd,
 
 	init.func = init32.func;
 	init.sarea_priv_offset = init32.sarea_priv_offset;
-	memcpy(&init.chipset, &init32.chipset,
-		offsetof(drm_mga_init_t, fb_offset) -
-		offsetof(drm_mga_init_t, chipset));
+	memcpy(&init.always32bit, &init32.always32bit,
+	       sizeof(init32.always32bit));
 	init.fb_offset = init32.fb_offset;
 	init.mmio_offset = init32.mmio_offset;
 	init.status_offset = init32.status_offset;
diff --git a/include/uapi/drm/mga_drm.h b/include/uapi/drm/mga_drm.h
index 8c4337548ab5..2978a435dff9 100644
--- a/include/uapi/drm/mga_drm.h
+++ b/include/uapi/drm/mga_drm.h
@@ -279,20 +279,22 @@ typedef struct drm_mga_init {
 
 	unsigned long sarea_priv_offset;
 
-	int chipset;
-	int sgram;
+	__struct_group(/* no tye */, always32bit, /* no attrs */,
+		int chipset;
+		int sgram;
 
-	unsigned int maccess;
+		unsigned int maccess;
 
-	unsigned int fb_cpp;
-	unsigned int front_offset, front_pitch;
-	unsigned int back_offset, back_pitch;
+		unsigned int fb_cpp;
+		unsigned int front_offset, front_pitch;
+		unsigned int back_offset, back_pitch;
 
-	unsigned int depth_cpp;
-	unsigned int depth_offset, depth_pitch;
+		unsigned int depth_cpp;
+		unsigned int depth_offset, depth_pitch;
 
-	unsigned int texture_offset[MGA_NR_TEX_HEAPS];
-	unsigned int texture_size[MGA_NR_TEX_HEAPS];
+		unsigned int texture_offset[MGA_NR_TEX_HEAPS];
+		unsigned int texture_size[MGA_NR_TEX_HEAPS];
+	);
 
 	unsigned long fb_offset;
 	unsigned long mmio_offset;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 21/63] net/mlx5e: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (19 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 20/63] drm/mga/mga_ioc32: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 22/63] HID: cp2112: " Kees Cook
                   ` (41 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Saeed Mahameed, Leon Romanovsky, David S. Miller,
	Jakub Kicinski, netdev, linux-rdma, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct vlan_ethhdr around members h_dest and
h_source, so they can be referenced together. This will allow memcpy()
and sizeof() to more easily reason about sizes, improve readability,
and avoid future warnings about writing beyond the end of h_dest.

"pahole" shows no size nor member offset changes to struct vlan_ethhdr.
"objdump -d" shows no object code changes.

Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tx.c | 2 +-
 include/linux/if_vlan.h                         | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
index c63d78eda606..39942a952736 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -207,7 +207,7 @@ static inline void mlx5e_insert_vlan(void *start, struct sk_buff *skb, u16 ihs)
 	int cpy1_sz = 2 * ETH_ALEN;
 	int cpy2_sz = ihs - cpy1_sz;
 
-	memcpy(vhdr, skb->data, cpy1_sz);
+	memcpy(&vhdr->addrs, skb->data, cpy1_sz);
 	vhdr->h_vlan_proto = skb->vlan_proto;
 	vhdr->h_vlan_TCI = cpu_to_be16(skb_vlan_tag_get(skb));
 	memcpy(&vhdr->h_vlan_encapsulated_proto, skb->data + cpy1_sz, cpy2_sz);
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 41a518336673..45aad461aa34 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -46,8 +46,10 @@ struct vlan_hdr {
  *	@h_vlan_encapsulated_proto: packet type ID or len
  */
 struct vlan_ethhdr {
-	unsigned char	h_dest[ETH_ALEN];
-	unsigned char	h_source[ETH_ALEN];
+	struct_group(addrs,
+		unsigned char	h_dest[ETH_ALEN];
+		unsigned char	h_source[ETH_ALEN];
+	);
 	__be16		h_vlan_proto;
 	__be16		h_vlan_TCI;
 	__be16		h_vlan_encapsulated_proto;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 22/63] HID: cp2112: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (20 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 21/63] net/mlx5e: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-20 13:01   ` Jiri Kosina
  2021-08-18  6:04 ` [PATCH v2 23/63] media: omap3isp: " Kees Cook
                   ` (40 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Jiri Kosina, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct cp2112_string_report around members report,
length, type, and string, so they can be referenced together. This will
allow memcpy() and sizeof() to more easily reason about sizes, improve
readability, and avoid future warnings about writing beyond the end of
report.

"pahole" shows no size nor member offset changes to struct
cp2112_string_report.  "objdump -d" shows no meaningful object
code changes (i.e. only source line number induced differences.)

Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/hid/hid-cp2112.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 477baa30889c..ece147d1a278 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -129,10 +129,12 @@ struct cp2112_xfer_status_report {
 
 struct cp2112_string_report {
 	u8 dummy;		/* force .string to be aligned */
-	u8 report;		/* CP2112_*_STRING */
-	u8 length;		/* length in bytes of everyting after .report */
-	u8 type;		/* USB_DT_STRING */
-	wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
+	struct_group_attr(contents, __packed,
+		u8 report;		/* CP2112_*_STRING */
+		u8 length;		/* length in bytes of everything after .report */
+		u8 type;		/* USB_DT_STRING */
+		wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
+	);
 } __packed;
 
 /* Number of times to request transfer status before giving up waiting for a
@@ -986,8 +988,8 @@ static ssize_t pstr_show(struct device *kdev,
 	u8 length;
 	int ret;
 
-	ret = cp2112_hid_get(hdev, attr->report, &report.report,
-			     sizeof(report) - 1, HID_FEATURE_REPORT);
+	ret = cp2112_hid_get(hdev, attr->report, (u8 *)&report.contents,
+			     sizeof(report.contents), HID_FEATURE_REPORT);
 	if (ret < 3) {
 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
 			ret);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 23/63] media: omap3isp: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (21 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 22/63] HID: cp2112: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 24/63] sata_fsl: " Kees Cook
                   ` (39 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields. Wrap the target region
in struct_group(). This additionally fixes a theoretical misalignment
of the copy (since the size of "buf" changes between 64-bit and 32-bit,
but this is likely never built for 64-bit).

FWIW, I think this code is totally broken on 64-bit (which appears to
not be a "real" build configuration): it would either always fail (with
an uninitialized data->buf_size) or would cause corruption in userspace
due to the copy_to_user() in the call path against an uninitialized
data->buf value:

omap3isp_stat_request_statistics_time32(...)
    struct omap3isp_stat_data data64;
    ...
    omap3isp_stat_request_statistics(stat, &data64);

int omap3isp_stat_request_statistics(struct ispstat *stat,
                                     struct omap3isp_stat_data *data)
    ...
    buf = isp_stat_buf_get(stat, data);

static struct ispstat_buffer *isp_stat_buf_get(struct ispstat *stat,
                                               struct omap3isp_stat_data *data)
...
    if (buf->buf_size > data->buf_size) {
            ...
            return ERR_PTR(-EINVAL);
    }
    ...
    rval = copy_to_user(data->buf,
                        buf->virt_addr,
                        buf->buf_size);

Regardless, additionally initialize data64 to be zero-filled to avoid
undefined behavior.

Fixes: 378e3f81cb56 ("media: omap3isp: support 64-bit version of omap3isp_stat_data")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/media/platform/omap3isp/ispstat.c |  5 +++--
 include/uapi/linux/omap3isp.h             | 21 +++++++++++++--------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/media/platform/omap3isp/ispstat.c b/drivers/media/platform/omap3isp/ispstat.c
index 5b9b57f4d9bf..68cf68dbcace 100644
--- a/drivers/media/platform/omap3isp/ispstat.c
+++ b/drivers/media/platform/omap3isp/ispstat.c
@@ -512,7 +512,7 @@ int omap3isp_stat_request_statistics(struct ispstat *stat,
 int omap3isp_stat_request_statistics_time32(struct ispstat *stat,
 					struct omap3isp_stat_data_time32 *data)
 {
-	struct omap3isp_stat_data data64;
+	struct omap3isp_stat_data data64 = { };
 	int ret;
 
 	ret = omap3isp_stat_request_statistics(stat, &data64);
@@ -521,7 +521,8 @@ int omap3isp_stat_request_statistics_time32(struct ispstat *stat,
 
 	data->ts.tv_sec = data64.ts.tv_sec;
 	data->ts.tv_usec = data64.ts.tv_usec;
-	memcpy(&data->buf, &data64.buf, sizeof(*data) - sizeof(data->ts));
+	data->buf = (uintptr_t)data64.buf;
+	memcpy(&data->frame, &data64.frame, sizeof(data->frame));
 
 	return 0;
 }
diff --git a/include/uapi/linux/omap3isp.h b/include/uapi/linux/omap3isp.h
index 87b55755f4ff..9a6b3ed11455 100644
--- a/include/uapi/linux/omap3isp.h
+++ b/include/uapi/linux/omap3isp.h
@@ -162,6 +162,7 @@ struct omap3isp_h3a_aewb_config {
  * struct omap3isp_stat_data - Statistic data sent to or received from user
  * @ts: Timestamp of returned framestats.
  * @buf: Pointer to pass to user.
+ * @buf_size: Size of buffer.
  * @frame_number: Frame number of requested stats.
  * @cur_frame: Current frame number being processed.
  * @config_counter: Number of the configuration associated with the data.
@@ -176,10 +177,12 @@ struct omap3isp_stat_data {
 	struct timeval ts;
 #endif
 	void __user *buf;
-	__u32 buf_size;
-	__u16 frame_number;
-	__u16 cur_frame;
-	__u16 config_counter;
+	__struct_group(/* no type */, frame, /* no attrs */,
+		__u32 buf_size;
+		__u16 frame_number;
+		__u16 cur_frame;
+		__u16 config_counter;
+	);
 };
 
 #ifdef __KERNEL__
@@ -189,10 +192,12 @@ struct omap3isp_stat_data_time32 {
 		__s32	tv_usec;
 	} ts;
 	__u32 buf;
-	__u32 buf_size;
-	__u16 frame_number;
-	__u16 cur_frame;
-	__u16 config_counter;
+	__struct_group(/* no type */, frame, /* no attrs */,
+		__u32 buf_size;
+		__u16 frame_number;
+		__u16 cur_frame;
+		__u16 config_counter;
+	);
 };
 #endif
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 24/63] sata_fsl: Use struct_group() for memcpy() region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (22 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 23/63] media: omap3isp: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 25/63] compiler_types.h: Remove __compiletime_object_size() Kees Cook
                   ` (38 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Jens Axboe, linux-ide, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct command_desc around members acmd and fill,
so they can be referenced together. This will allow memset(), memcpy(),
and sizeof() to more easily reason about sizes, improve readability,
and avoid future warnings about writing beyond the end of acmd:

In function 'fortify_memset_chk',
    inlined from 'sata_fsl_qc_prep' at drivers/ata/sata_fsl.c:534:3:
./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
  199 |    __write_overflow_field();
      |    ^~~~~~~~~~~~~~~~~~~~~~~~

Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-ide@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/ata/sata_fsl.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index e5838b23c9e0..fec3c9032606 100644
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -246,8 +246,10 @@ enum {
 struct command_desc {
 	u8 cfis[8 * 4];
 	u8 sfis[8 * 4];
-	u8 acmd[4 * 4];
-	u8 fill[4 * 4];
+	struct_group(cdb,
+		u8 acmd[4 * 4];
+		u8 fill[4 * 4];
+	);
 	u32 prdt[SATA_FSL_MAX_PRD_DIRECT * 4];
 	u32 prdt_indirect[(SATA_FSL_MAX_PRD - SATA_FSL_MAX_PRD_DIRECT) * 4];
 };
@@ -531,8 +533,8 @@ static enum ata_completion_errors sata_fsl_qc_prep(struct ata_queued_cmd *qc)
 	/* setup "ACMD - atapi command" in cmd. desc. if this is ATAPI cmd */
 	if (ata_is_atapi(qc->tf.protocol)) {
 		desc_info |= ATAPI_CMD;
-		memset((void *)&cd->acmd, 0, 32);
-		memcpy((void *)&cd->acmd, qc->cdb, qc->dev->cdb_len);
+		memset(&cd->cdb, 0, sizeof(cd->cdb));
+		memcpy(&cd->cdb, qc->cdb, qc->dev->cdb_len);
 	}
 
 	if (qc->flags & ATA_QCFLAG_DMAMAP)
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 25/63] compiler_types.h: Remove __compiletime_object_size()
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (23 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 24/63] sata_fsl: " Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18 13:02   ` Miguel Ojeda
  2021-08-18  6:04 ` [PATCH v2 26/63] lib/string: Move helper functions out of string.c Kees Cook
                   ` (37 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Nick Desaulniers, Nathan Chancellor, Miguel Ojeda,
	Sedat Dilek, Will Deacon, Marco Elver, Arvind Sankar,
	Masahiro Yamada, Luc Van Oostenryck, Andrew Morton,
	Sami Tolvanen, Thomas Gleixner, Gabriel Krisman Bertazi,
	Andy Lutomirski, Oleg Nesterov, Gustavo A. R. Silva,
	Greg Kroah-Hartman, linux-wireless, netdev, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

Since all compilers support __builtin_object_size(), and there is only
one user of __compiletime_object_size, remove it to avoid the needless
indirection. This lets Clang reason about check_copy_size() correctly.

Link: https://github.com/ClangBuiltLinux/linux/issues/1179
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/compiler-gcc.h   | 2 --
 include/linux/compiler_types.h | 4 ----
 include/linux/thread_info.h    | 2 +-
 3 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index cb9217fc60af..01985821944b 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -41,8 +41,6 @@
 
 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
 
-#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
-
 #define __compiletime_warning(message) __attribute__((__warning__(message)))
 #define __compiletime_error(message) __attribute__((__error__(message)))
 
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index e4ea86fc584d..c43308b0a9a9 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -290,10 +290,6 @@ struct ftrace_likely_data {
 	(sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
 	 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
 
-/* Compile time object size, -1 for unknown */
-#ifndef __compiletime_object_size
-# define __compiletime_object_size(obj) -1
-#endif
 #ifndef __compiletime_warning
 # define __compiletime_warning(message)
 #endif
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 0999f6317978..ad0c4e041030 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -203,7 +203,7 @@ static inline void copy_overflow(int size, unsigned long count)
 static __always_inline __must_check bool
 check_copy_size(const void *addr, size_t bytes, bool is_source)
 {
-	int sz = __compiletime_object_size(addr);
+	int sz = __builtin_object_size(addr, 0);
 	if (unlikely(sz >= 0 && sz < bytes)) {
 		if (!__builtin_constant_p(bytes))
 			copy_overflow(sz, bytes);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 26/63] lib/string: Move helper functions out of string.c
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (24 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 25/63] compiler_types.h: Remove __compiletime_object_size() Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  9:35   ` Andy Shevchenko
  2021-08-18  6:04 ` [PATCH v2 27/63] fortify: Move remaining fortify helpers into fortify-string.h Kees Cook
                   ` (36 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Andy Shevchenko, Andrew Morton, Nick Desaulniers,
	Andy Lavr, Nathan Chancellor, Alexey Dobriyan, Stephen Rothwell,
	Bartosz Golaszewski, Gustavo A. R. Silva, Greg Kroah-Hartman,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

The core functions of string.c are those that may be implemented by
per-architecture functions, or overloaded by FORTIFY_SOURCE. As a
result, it needs to be built with __NO_FORTIFY. Without this, macros
will collide with function declarations. This was accidentally working
due to -ffreestanding (on some architectures). Make this deterministic
by explicitly setting __NO_FORTIFY and move all the helper functions
into string_helpers.c so that they gain the fortification coverage they
had been missing.

Cc: Andy Shevchenko <andy@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andy Lavr <andy.lavr@gmail.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm/boot/compressed/string.c     |   1 +
 arch/s390/lib/string.c                |   3 +
 arch/x86/boot/compressed/misc.h       |   2 +
 arch/x86/boot/compressed/pgtable_64.c |   2 +
 arch/x86/lib/string_32.c              |   1 +
 lib/string.c                          | 210 +-------------------------
 lib/string_helpers.c                  | 193 +++++++++++++++++++++++
 7 files changed, 208 insertions(+), 204 deletions(-)

diff --git a/arch/arm/boot/compressed/string.c b/arch/arm/boot/compressed/string.c
index 8c0fa276d994..fcc678fce045 100644
--- a/arch/arm/boot/compressed/string.c
+++ b/arch/arm/boot/compressed/string.c
@@ -5,6 +5,7 @@
  * Small subset of simple string routines
  */
 
+#define __NO_FORTIFY
 #include <linux/string.h>
 
 /*
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
index cfcdf76d6a95..392fb9f4f4db 100644
--- a/arch/s390/lib/string.c
+++ b/arch/s390/lib/string.c
@@ -8,6 +8,9 @@
  */
 
 #define IN_ARCH_STRING_C 1
+#ifndef __NO_FORTIFY
+# define __NO_FORTIFY
+#endif
 
 #include <linux/types.h>
 #include <linux/string.h>
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 31139256859f..49bde196da9b 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -14,6 +14,8 @@
 #undef CONFIG_KASAN
 #undef CONFIG_KASAN_GENERIC
 
+#define __NO_FORTIFY
+
 /* cpu_feature_enabled() cannot be used this early */
 #define USE_EARLY_PGTABLE_L5
 
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
index 2a78746f5a4c..a1733319a22a 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "misc.h"
 #include <linux/efi.h>
 #include <asm/e820/types.h>
 #include <asm/processor.h>
diff --git a/arch/x86/lib/string_32.c b/arch/x86/lib/string_32.c
index d15fdae9656e..53b3f202267c 100644
--- a/arch/x86/lib/string_32.c
+++ b/arch/x86/lib/string_32.c
@@ -11,6 +11,7 @@
  * strings.
  */
 
+#define __NO_FORTIFY
 #include <linux/string.h>
 #include <linux/export.h>
 
diff --git a/lib/string.c b/lib/string.c
index 4fec38fc6e58..4e111d9dd6d5 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -6,20 +6,15 @@
  */
 
 /*
- * stupid library routines.. The optimized versions should generally be found
- * as inline code in <asm-xx/string.h>
+ * This file should be used only for "library" routines that may have
+ * alternative implementations on specific architectures (generally
+ * found in <asm-xx/string.h>), or get overloaded by FORTIFY_SOURCE.
+ * (Specifically, this file is built with __NO_FORTIFY.)
  *
- * These are buggy as well..
- *
- * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
- * -  Added strsep() which will replace strtok() soon (because strsep() is
- *    reentrant and should be faster). Use only strsep() in new code, please.
- *
- * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>,
- *                    Matthew Hawkins <matt@mh.dropbear.id.au>
- * -  Kissed strtok() goodbye
+ * Other helper functions should live in string_helpers.c.
  */
 
+#define __NO_FORTIFY
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
@@ -254,40 +249,6 @@ ssize_t strscpy(char *dest, const char *src, size_t count)
 EXPORT_SYMBOL(strscpy);
 #endif
 
-/**
- * strscpy_pad() - Copy a C-string into a sized buffer
- * @dest: Where to copy the string to
- * @src: Where to copy the string from
- * @count: Size of destination buffer
- *
- * Copy the string, or as much of it as fits, into the dest buffer.  The
- * behavior is undefined if the string buffers overlap.  The destination
- * buffer is always %NUL terminated, unless it's zero-sized.
- *
- * If the source string is shorter than the destination buffer, zeros
- * the tail of the destination buffer.
- *
- * For full explanation of why you may want to consider using the
- * 'strscpy' functions please see the function docstring for strscpy().
- *
- * Returns:
- * * The number of characters copied (not including the trailing %NUL)
- * * -E2BIG if count is 0 or @src was truncated.
- */
-ssize_t strscpy_pad(char *dest, const char *src, size_t count)
-{
-	ssize_t written;
-
-	written = strscpy(dest, src, count);
-	if (written < 0 || written == count - 1)
-		return written;
-
-	memset(dest + written + 1, 0, count - written - 1);
-
-	return written;
-}
-EXPORT_SYMBOL(strscpy_pad);
-
 /**
  * stpcpy - copy a string from src to dest returning a pointer to the new end
  *          of dest, including src's %NUL-terminator. May overrun dest.
@@ -530,46 +491,6 @@ char *strnchr(const char *s, size_t count, int c)
 EXPORT_SYMBOL(strnchr);
 #endif
 
-/**
- * skip_spaces - Removes leading whitespace from @str.
- * @str: The string to be stripped.
- *
- * Returns a pointer to the first non-whitespace character in @str.
- */
-char *skip_spaces(const char *str)
-{
-	while (isspace(*str))
-		++str;
-	return (char *)str;
-}
-EXPORT_SYMBOL(skip_spaces);
-
-/**
- * strim - Removes leading and trailing whitespace from @s.
- * @s: The string to be stripped.
- *
- * Note that the first trailing whitespace is replaced with a %NUL-terminator
- * in the given string @s. Returns a pointer to the first non-whitespace
- * character in @s.
- */
-char *strim(char *s)
-{
-	size_t size;
-	char *end;
-
-	size = strlen(s);
-	if (!size)
-		return s;
-
-	end = s + size - 1;
-	while (end >= s && isspace(*end))
-		end--;
-	*(end + 1) = '\0';
-
-	return skip_spaces(s);
-}
-EXPORT_SYMBOL(strim);
-
 #ifndef __HAVE_ARCH_STRLEN
 /**
  * strlen - Find the length of a string
@@ -704,101 +625,6 @@ char *strsep(char **s, const char *ct)
 EXPORT_SYMBOL(strsep);
 #endif
 
-/**
- * sysfs_streq - return true if strings are equal, modulo trailing newline
- * @s1: one string
- * @s2: another string
- *
- * This routine returns true iff two strings are equal, treating both
- * NUL and newline-then-NUL as equivalent string terminations.  It's
- * geared for use with sysfs input strings, which generally terminate
- * with newlines but are compared against values without newlines.
- */
-bool sysfs_streq(const char *s1, const char *s2)
-{
-	while (*s1 && *s1 == *s2) {
-		s1++;
-		s2++;
-	}
-
-	if (*s1 == *s2)
-		return true;
-	if (!*s1 && *s2 == '\n' && !s2[1])
-		return true;
-	if (*s1 == '\n' && !s1[1] && !*s2)
-		return true;
-	return false;
-}
-EXPORT_SYMBOL(sysfs_streq);
-
-/**
- * match_string - matches given string in an array
- * @array:	array of strings
- * @n:		number of strings in the array or -1 for NULL terminated arrays
- * @string:	string to match with
- *
- * This routine will look for a string in an array of strings up to the
- * n-th element in the array or until the first NULL element.
- *
- * Historically the value of -1 for @n, was used to search in arrays that
- * are NULL terminated. However, the function does not make a distinction
- * when finishing the search: either @n elements have been compared OR
- * the first NULL element was found.
- *
- * Return:
- * index of a @string in the @array if matches, or %-EINVAL otherwise.
- */
-int match_string(const char * const *array, size_t n, const char *string)
-{
-	int index;
-	const char *item;
-
-	for (index = 0; index < n; index++) {
-		item = array[index];
-		if (!item)
-			break;
-		if (!strcmp(item, string))
-			return index;
-	}
-
-	return -EINVAL;
-}
-EXPORT_SYMBOL(match_string);
-
-/**
- * __sysfs_match_string - matches given string in an array
- * @array: array of strings
- * @n: number of strings in the array or -1 for NULL terminated arrays
- * @str: string to match with
- *
- * Returns index of @str in the @array or -EINVAL, just like match_string().
- * Uses sysfs_streq instead of strcmp for matching.
- *
- * This routine will look for a string in an array of strings up to the
- * n-th element in the array or until the first NULL element.
- *
- * Historically the value of -1 for @n, was used to search in arrays that
- * are NULL terminated. However, the function does not make a distinction
- * when finishing the search: either @n elements have been compared OR
- * the first NULL element was found.
- */
-int __sysfs_match_string(const char * const *array, size_t n, const char *str)
-{
-	const char *item;
-	int index;
-
-	for (index = 0; index < n; index++) {
-		item = array[index];
-		if (!item)
-			break;
-		if (sysfs_streq(item, str))
-			return index;
-	}
-
-	return -EINVAL;
-}
-EXPORT_SYMBOL(__sysfs_match_string);
-
 #ifndef __HAVE_ARCH_MEMSET
 /**
  * memset - Fill a region of memory with the given value
@@ -1221,27 +1047,3 @@ void *memchr_inv(const void *start, int c, size_t bytes)
 	return check_bytes8(start, value, bytes % 8);
 }
 EXPORT_SYMBOL(memchr_inv);
-
-/**
- * strreplace - Replace all occurrences of character in string.
- * @s: The string to operate on.
- * @old: The character being replaced.
- * @new: The character @old is replaced with.
- *
- * Returns pointer to the nul byte at the end of @s.
- */
-char *strreplace(char *s, char old, char new)
-{
-	for (; *s; ++s)
-		if (*s == old)
-			*s = new;
-	return s;
-}
-EXPORT_SYMBOL(strreplace);
-
-void fortify_panic(const char *name)
-{
-	pr_emerg("detected buffer overflow in %s\n", name);
-	BUG();
-}
-EXPORT_SYMBOL(fortify_panic);
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 3806a52ce697..bde13612c25d 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -696,3 +696,196 @@ void kfree_strarray(char **array, size_t n)
 	kfree(array);
 }
 EXPORT_SYMBOL_GPL(kfree_strarray);
+
+/**
+ * strscpy_pad() - Copy a C-string into a sized buffer
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @count: Size of destination buffer
+ *
+ * Copy the string, or as much of it as fits, into the dest buffer.  The
+ * behavior is undefined if the string buffers overlap.  The destination
+ * buffer is always %NUL terminated, unless it's zero-sized.
+ *
+ * If the source string is shorter than the destination buffer, zeros
+ * the tail of the destination buffer.
+ *
+ * For full explanation of why you may want to consider using the
+ * 'strscpy' functions please see the function docstring for strscpy().
+ *
+ * Returns:
+ * * The number of characters copied (not including the trailing %NUL)
+ * * -E2BIG if count is 0 or @src was truncated.
+ */
+ssize_t strscpy_pad(char *dest, const char *src, size_t count)
+{
+	ssize_t written;
+
+	written = strscpy(dest, src, count);
+	if (written < 0 || written == count - 1)
+		return written;
+
+	memset(dest + written + 1, 0, count - written - 1);
+
+	return written;
+}
+EXPORT_SYMBOL(strscpy_pad);
+
+/**
+ * skip_spaces - Removes leading whitespace from @str.
+ * @str: The string to be stripped.
+ *
+ * Returns a pointer to the first non-whitespace character in @str.
+ */
+char *skip_spaces(const char *str)
+{
+	while (isspace(*str))
+		++str;
+	return (char *)str;
+}
+EXPORT_SYMBOL(skip_spaces);
+
+/**
+ * strim - Removes leading and trailing whitespace from @s.
+ * @s: The string to be stripped.
+ *
+ * Note that the first trailing whitespace is replaced with a %NUL-terminator
+ * in the given string @s. Returns a pointer to the first non-whitespace
+ * character in @s.
+ */
+char *strim(char *s)
+{
+	size_t size;
+	char *end;
+
+	size = strlen(s);
+	if (!size)
+		return s;
+
+	end = s + size - 1;
+	while (end >= s && isspace(*end))
+		end--;
+	*(end + 1) = '\0';
+
+	return skip_spaces(s);
+}
+EXPORT_SYMBOL(strim);
+
+/**
+ * sysfs_streq - return true if strings are equal, modulo trailing newline
+ * @s1: one string
+ * @s2: another string
+ *
+ * This routine returns true iff two strings are equal, treating both
+ * NUL and newline-then-NUL as equivalent string terminations.  It's
+ * geared for use with sysfs input strings, which generally terminate
+ * with newlines but are compared against values without newlines.
+ */
+bool sysfs_streq(const char *s1, const char *s2)
+{
+	while (*s1 && *s1 == *s2) {
+		s1++;
+		s2++;
+	}
+
+	if (*s1 == *s2)
+		return true;
+	if (!*s1 && *s2 == '\n' && !s2[1])
+		return true;
+	if (*s1 == '\n' && !s1[1] && !*s2)
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(sysfs_streq);
+
+/**
+ * match_string - matches given string in an array
+ * @array:	array of strings
+ * @n:		number of strings in the array or -1 for NULL terminated arrays
+ * @string:	string to match with
+ *
+ * This routine will look for a string in an array of strings up to the
+ * n-th element in the array or until the first NULL element.
+ *
+ * Historically the value of -1 for @n, was used to search in arrays that
+ * are NULL terminated. However, the function does not make a distinction
+ * when finishing the search: either @n elements have been compared OR
+ * the first NULL element was found.
+ *
+ * Return:
+ * index of a @string in the @array if matches, or %-EINVAL otherwise.
+ */
+int match_string(const char * const *array, size_t n, const char *string)
+{
+	int index;
+	const char *item;
+
+	for (index = 0; index < n; index++) {
+		item = array[index];
+		if (!item)
+			break;
+		if (!strcmp(item, string))
+			return index;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(match_string);
+
+/**
+ * __sysfs_match_string - matches given string in an array
+ * @array: array of strings
+ * @n: number of strings in the array or -1 for NULL terminated arrays
+ * @str: string to match with
+ *
+ * Returns index of @str in the @array or -EINVAL, just like match_string().
+ * Uses sysfs_streq instead of strcmp for matching.
+ *
+ * This routine will look for a string in an array of strings up to the
+ * n-th element in the array or until the first NULL element.
+ *
+ * Historically the value of -1 for @n, was used to search in arrays that
+ * are NULL terminated. However, the function does not make a distinction
+ * when finishing the search: either @n elements have been compared OR
+ * the first NULL element was found.
+ */
+int __sysfs_match_string(const char * const *array, size_t n, const char *str)
+{
+	const char *item;
+	int index;
+
+	for (index = 0; index < n; index++) {
+		item = array[index];
+		if (!item)
+			break;
+		if (sysfs_streq(item, str))
+			return index;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(__sysfs_match_string);
+
+/**
+ * strreplace - Replace all occurrences of character in string.
+ * @s: The string to operate on.
+ * @old: The character being replaced.
+ * @new: The character @old is replaced with.
+ *
+ * Returns pointer to the nul byte at the end of @s.
+ */
+char *strreplace(char *s, char old, char new)
+{
+	for (; *s; ++s)
+		if (*s == old)
+			*s = new;
+	return s;
+}
+EXPORT_SYMBOL(strreplace);
+
+void fortify_panic(const char *name)
+{
+	pr_emerg("detected buffer overflow in %s\n", name);
+	BUG();
+}
+EXPORT_SYMBOL(fortify_panic);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 27/63] fortify: Move remaining fortify helpers into fortify-string.h
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (25 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 26/63] lib/string: Move helper functions out of string.c Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18 19:05   ` Francis Laniel
  2021-08-18  6:04 ` [PATCH v2 28/63] fortify: Explicitly disable Clang support Kees Cook
                   ` (35 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Andrew Morton, Francis Laniel, Daniel Axtens,
	Vincenzo Frascino, Andrey Konovalov, Dan Williams,
	Gustavo A. R. Silva, Greg Kroah-Hartman, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

When commit a28a6e860c6c ("string.h: move fortified functions definitions
in a dedicated header.") moved the fortify-specific code, some helpers
were left behind. Moves the remaining fortify-specific helpers into
fortify-string.h so they're together where they're used. This requires
that any FORTIFY helper function prototypes be conditionally built to
avoid "no prototype" warnings. Additionally removes unused helpers.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Francis Laniel <laniel_francis@privacyrequired.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h | 7 +++++++
 include/linux/string.h         | 9 ---------
 lib/string_helpers.c           | 2 ++
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index c1be37437e77..7e67d02764db 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -2,6 +2,13 @@
 #ifndef _LINUX_FORTIFY_STRING_H_
 #define _LINUX_FORTIFY_STRING_H_
 
+#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
+#define __RENAME(x) __asm__(#x)
+
+void fortify_panic(const char *name) __noreturn __cold;
+void __read_overflow(void) __compiletime_error("detected read beyond size of object (1st parameter)");
+void __read_overflow2(void) __compiletime_error("detected read beyond size of object (2nd parameter)");
+void __write_overflow(void) __compiletime_error("detected write beyond size of object (1st parameter)");
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
diff --git a/include/linux/string.h b/include/linux/string.h
index b48d2d28e0b1..9473f81b9db2 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -249,15 +249,6 @@ static inline const char *kbasename(const char *path)
 	return tail ? tail + 1 : path;
 }
 
-#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
-#define __RENAME(x) __asm__(#x)
-
-void fortify_panic(const char *name) __noreturn __cold;
-void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
-void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
-void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
-void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
-
 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 #include <linux/fortify-string.h>
 #endif
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index bde13612c25d..faa9d8e4e2c5 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -883,9 +883,11 @@ char *strreplace(char *s, char old, char new)
 }
 EXPORT_SYMBOL(strreplace);
 
+#ifdef CONFIG_FORTIFY_SOURCE
 void fortify_panic(const char *name)
 {
 	pr_emerg("detected buffer overflow in %s\n", name);
 	BUG();
 }
 EXPORT_SYMBOL(fortify_panic);
+#endif /* CONFIG_FORTIFY_SOURCE */
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 28/63] fortify: Explicitly disable Clang support
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (26 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 27/63] fortify: Move remaining fortify helpers into fortify-string.h Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:04 ` [PATCH v2 29/63] fortify: Fix dropped strcpy() compile-time write overflow check Kees Cook
                   ` (34 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Clang has never correctly compiled the FORTIFY_SOURCE defenses due to
a couple bugs:

	Eliding inlines with matching __builtin_* names
	https://bugs.llvm.org/show_bug.cgi?id=50322

	Incorrect __builtin_constant_p() of some globals
	https://bugs.llvm.org/show_bug.cgi?id=41459

In the process of making improvements to the FORTIFY_SOURCE defenses, the
first (silent) bug (coincidentally) becomes worked around, but exposes
the latter which breaks the build. As such, Clang must not be used with
CONFIG_FORTIFY_SOURCE until at least latter bug is fixed (in Clang 13),
and the fortify routines have been rearranged.

Update the Kconfig to reflect the reality of the current situation.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 security/Kconfig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/security/Kconfig b/security/Kconfig
index 0ced7fd33e4d..fe6c0395fa02 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -191,6 +191,9 @@ config HARDENED_USERCOPY_PAGESPAN
 config FORTIFY_SOURCE
 	bool "Harden common str/mem functions against buffer overflows"
 	depends on ARCH_HAS_FORTIFY_SOURCE
+	# https://bugs.llvm.org/show_bug.cgi?id=50322
+	# https://bugs.llvm.org/show_bug.cgi?id=41459
+	depends on !CC_IS_CLANG
 	help
 	  Detect overflows of buffers in common string and memory functions
 	  where the compiler can determine and validate the buffer sizes.
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 29/63] fortify: Fix dropped strcpy() compile-time write overflow check
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (27 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 28/63] fortify: Explicitly disable Clang support Kees Cook
@ 2021-08-18  6:04 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 30/63] fortify: Prepare to improve strnlen() and strlen() warnings Kees Cook
                   ` (33 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Daniel Axtens, Francis Laniel, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

The implementation for intra-object overflow in str*-family functions
accidentally dropped compile-time write overflow checking in strcpy(),
leaving it entirely to run-time. Add back the intended check.

Fixes: 6a39e62abbaf ("lib: string.h: detect intra-object overflow in fortified string functions")
Cc: Daniel Axtens <dja@axtens.net>
Cc: Francis Laniel <laniel_francis@privacyrequired.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 7e67d02764db..68bc5978d916 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -287,7 +287,10 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 	if (p_size == (size_t)-1 && q_size == (size_t)-1)
 		return __underlying_strcpy(p, q);
 	size = strlen(q) + 1;
-	/* test here to use the more stringent object size */
+	/* Compile-time check for const size overflow. */
+	if (__builtin_constant_p(size) && p_size < size)
+		__write_overflow();
+	/* Run-time check for dynamic size overflow. */
 	if (p_size < size)
 		fortify_panic(__func__);
 	memcpy(p, q, size);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 30/63] fortify: Prepare to improve strnlen() and strlen() warnings
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (28 preceding siblings ...)
  2021-08-18  6:04 ` [PATCH v2 29/63] fortify: Fix dropped strcpy() compile-time write overflow check Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 31/63] fortify: Allow strlen() and strnlen() to pass compile-time known lengths Kees Cook
                   ` (32 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Francis Laniel, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In order to have strlen() use fortified strnlen() internally, swap their
positions in the source. Doing this as part of later changes makes
review difficult, so reoroder it here; no code changes.

Cc: Francis Laniel <laniel_francis@privacyrequired.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 68bc5978d916..a3cb1d9aacce 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -56,6 +56,17 @@ __FORTIFY_INLINE char *strcat(char *p, const char *q)
 	return p;
 }
 
+extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
+__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
+{
+	size_t p_size = __builtin_object_size(p, 1);
+	__kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
+
+	if (p_size <= ret && maxlen != ret)
+		fortify_panic(__func__);
+	return ret;
+}
+
 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 {
 	__kernel_size_t ret;
@@ -71,17 +82,6 @@ __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 	return ret;
 }
 
-extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
-__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
-{
-	size_t p_size = __builtin_object_size(p, 1);
-	__kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
-
-	if (p_size <= ret && maxlen != ret)
-		fortify_panic(__func__);
-	return ret;
-}
-
 /* defined after fortified strlen to reuse it */
 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 31/63] fortify: Allow strlen() and strnlen() to pass compile-time known lengths
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (29 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 30/63] fortify: Prepare to improve strnlen() and strlen() warnings Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 32/63] fortify: Add compile-time FORTIFY_SOURCE tests Kees Cook
                   ` (31 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Under CONFIG_FORTIFY_SOURCE, it is possible for the compiler to perform
strlen() and strnlen() at compile-time when the string size is known.
This is required to support compile-time overflow checking in strlcpy().

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h | 47 ++++++++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 11 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index a3cb1d9aacce..e232a63fd826 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -10,6 +10,18 @@ void __read_overflow(void) __compiletime_error("detected read beyond size of obj
 void __read_overflow2(void) __compiletime_error("detected read beyond size of object (2nd parameter)");
 void __write_overflow(void) __compiletime_error("detected write beyond size of object (1st parameter)");
 
+#define __compiletime_strlen(p)	({		\
+	size_t ret = (size_t)-1;			\
+	size_t p_size = __builtin_object_size(p, 1);	\
+	if (p_size != (size_t)-1) {			\
+		size_t p_len = p_size - 1;		\
+		if (__builtin_constant_p(p[p_len]) &&	\
+		    p[p_len] == '\0')			\
+			ret = __builtin_strlen(p);	\
+	}						\
+	ret;						\
+})
+
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
@@ -60,21 +72,31 @@ extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(st
 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
 {
 	size_t p_size = __builtin_object_size(p, 1);
-	__kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
+	size_t p_len = __compiletime_strlen(p);
+	size_t ret;
+
+	/* We can take compile-time actions when maxlen is const. */
+	if (__builtin_constant_p(maxlen) && p_len != (size_t)-1) {
+		/* If p is const, we can use its compile-time-known len. */
+		if (maxlen >= p_size)
+			return p_len;
+	}
 
+	/* Do no check characters beyond the end of p. */
+	ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
 	if (p_size <= ret && maxlen != ret)
 		fortify_panic(__func__);
 	return ret;
 }
 
+/* defined after fortified strnlen to reuse it. */
 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 {
 	__kernel_size_t ret;
 	size_t p_size = __builtin_object_size(p, 1);
 
-	/* Work around gcc excess stack consumption issue */
-	if (p_size == (size_t)-1 ||
-		(__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
+	/* Give up if we don't know how large p is. */
+	if (p_size == (size_t)-1)
 		return __underlying_strlen(p);
 	ret = strnlen(p, p_size);
 	if (p_size <= ret)
@@ -86,24 +108,27 @@ __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
 {
-	size_t ret;
 	size_t p_size = __builtin_object_size(p, 1);
 	size_t q_size = __builtin_object_size(q, 1);
+	size_t q_len;	/* Full count of source string length. */
+	size_t len;	/* Count of characters going into destination. */
 
 	if (p_size == (size_t)-1 && q_size == (size_t)-1)
 		return __real_strlcpy(p, q, size);
-	ret = strlen(q);
-	if (size) {
-		size_t len = (ret >= size) ? size - 1 : ret;
-
-		if (__builtin_constant_p(len) && len >= p_size)
+	q_len = strlen(q);
+	len = (q_len >= size) ? size - 1 : q_len;
+	if (__builtin_constant_p(size) && __builtin_constant_p(q_len) && size) {
+		/* Write size is always larger than destintation. */
+		if (len >= p_size)
 			__write_overflow();
+	}
+	if (size) {
 		if (len >= p_size)
 			fortify_panic(__func__);
 		__underlying_memcpy(p, q, len);
 		p[len] = '\0';
 	}
-	return ret;
+	return q_len;
 }
 
 /* defined after fortified strnlen to reuse it */
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 32/63] fortify: Add compile-time FORTIFY_SOURCE tests
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (30 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 31/63] fortify: Allow strlen() and strnlen() to pass compile-time known lengths Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 33/63] lib: Introduce CONFIG_TEST_MEMCPY Kees Cook
                   ` (30 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

While the run-time testing of FORTIFY_SOURCE is already present in
LKDTM, there is no testing of the expected compile-time detections. In
preparation for correctly supporting FORTIFY_SOURCE under Clang, adding
additional FORTIFY_SOURCE defenses, and making sure FORTIFY_SOURCE
doesn't silently regress with GCC, introduce a build-time test suite that
checks each expected compile-time failure condition.

As this is relatively backwards from standard build rules in the
sense that a successful test is actually a compile _failure_, create
a wrapper script to check for the correct errors, and wire it up as
a dummy dependency to lib/string.o, collecting the results into a log
file artifact.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 lib/.gitignore                                |  2 +
 lib/Makefile                                  | 33 +++++++++++
 lib/test_fortify/read_overflow-memchr.c       |  5 ++
 lib/test_fortify/read_overflow-memchr_inv.c   |  5 ++
 lib/test_fortify/read_overflow-memcmp.c       |  5 ++
 lib/test_fortify/read_overflow-memscan.c      |  5 ++
 lib/test_fortify/read_overflow2-memcmp.c      |  5 ++
 lib/test_fortify/read_overflow2-memcpy.c      |  5 ++
 lib/test_fortify/read_overflow2-memmove.c     |  5 ++
 lib/test_fortify/test_fortify.h               | 35 +++++++++++
 lib/test_fortify/write_overflow-memcpy.c      |  5 ++
 lib/test_fortify/write_overflow-memmove.c     |  5 ++
 lib/test_fortify/write_overflow-memset.c      |  5 ++
 lib/test_fortify/write_overflow-strcpy-lit.c  |  5 ++
 lib/test_fortify/write_overflow-strcpy.c      |  5 ++
 lib/test_fortify/write_overflow-strlcpy-src.c |  5 ++
 lib/test_fortify/write_overflow-strlcpy.c     |  5 ++
 lib/test_fortify/write_overflow-strncpy-src.c |  5 ++
 lib/test_fortify/write_overflow-strncpy.c     |  5 ++
 lib/test_fortify/write_overflow-strscpy.c     |  5 ++
 scripts/test_fortify.sh                       | 59 +++++++++++++++++++
 21 files changed, 214 insertions(+)
 create mode 100644 lib/test_fortify/read_overflow-memchr.c
 create mode 100644 lib/test_fortify/read_overflow-memchr_inv.c
 create mode 100644 lib/test_fortify/read_overflow-memcmp.c
 create mode 100644 lib/test_fortify/read_overflow-memscan.c
 create mode 100644 lib/test_fortify/read_overflow2-memcmp.c
 create mode 100644 lib/test_fortify/read_overflow2-memcpy.c
 create mode 100644 lib/test_fortify/read_overflow2-memmove.c
 create mode 100644 lib/test_fortify/test_fortify.h
 create mode 100644 lib/test_fortify/write_overflow-memcpy.c
 create mode 100644 lib/test_fortify/write_overflow-memmove.c
 create mode 100644 lib/test_fortify/write_overflow-memset.c
 create mode 100644 lib/test_fortify/write_overflow-strcpy-lit.c
 create mode 100644 lib/test_fortify/write_overflow-strcpy.c
 create mode 100644 lib/test_fortify/write_overflow-strlcpy-src.c
 create mode 100644 lib/test_fortify/write_overflow-strlcpy.c
 create mode 100644 lib/test_fortify/write_overflow-strncpy-src.c
 create mode 100644 lib/test_fortify/write_overflow-strncpy.c
 create mode 100644 lib/test_fortify/write_overflow-strscpy.c
 create mode 100644 scripts/test_fortify.sh

diff --git a/lib/.gitignore b/lib/.gitignore
index 5e7fa54c4536..e5e217b8307b 100644
--- a/lib/.gitignore
+++ b/lib/.gitignore
@@ -4,3 +4,5 @@
 /gen_crc32table
 /gen_crc64table
 /oid_registry_data.c
+/test_fortify.log
+/test_fortify/*.log
diff --git a/lib/Makefile b/lib/Makefile
index 5efd1b435a37..bd17c2bf43e1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -360,3 +360,36 @@ obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o
 obj-$(CONFIG_SLUB_KUNIT_TEST) += slub_kunit.o
 
 obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
+
+# FORTIFY_SOURCE compile-time behavior tests
+TEST_FORTIFY_SRCS = $(wildcard $(srctree)/$(src)/test_fortify/*-*.c)
+TEST_FORTIFY_LOGS = $(patsubst $(srctree)/$(src)/%.c, %.log, $(TEST_FORTIFY_SRCS))
+TEST_FORTIFY_LOG = test_fortify.log
+
+quiet_cmd_test_fortify = TEST    $@
+      cmd_test_fortify = $(CONFIG_SHELL) $(srctree)/scripts/test_fortify.sh \
+			$< $@ "$(NM)" $(CC) $(c_flags) \
+			$(call cc-disable-warning,fortify-source)
+
+targets += $(TEST_FORTIFY_LOGS)
+clean-files += $(TEST_FORTIFY_LOGS)
+clean-files += $(addsuffix .o, $(TEST_FORTIFY_LOGS))
+$(obj)/test_fortify/%.log: $(src)/test_fortify/%.c \
+			   $(src)/test_fortify/test_fortify.h \
+			   $(srctree)/include/linux/fortify-string.h \
+			   $(srctree)/scripts/test_fortify.sh \
+			   FORCE
+	$(call if_changed,test_fortify)
+
+quiet_cmd_gen_fortify_log = GEN     $@
+      cmd_gen_fortify_log = cat </dev/null $(filter-out FORCE,$^) 2>/dev/null > $@ || true
+
+targets += $(TEST_FORTIFY_LOG)
+clean-files += $(TEST_FORTIFY_LOG)
+$(obj)/$(TEST_FORTIFY_LOG): $(addprefix $(obj)/, $(TEST_FORTIFY_LOGS)) FORCE
+	$(call if_changed,gen_fortify_log)
+
+# Fake dependency to trigger the fortify tests.
+ifeq ($(CONFIG_FORTIFY_SOURCE),y)
+$(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG)
+endif
diff --git a/lib/test_fortify/read_overflow-memchr.c b/lib/test_fortify/read_overflow-memchr.c
new file mode 100644
index 000000000000..2743084b32af
--- /dev/null
+++ b/lib/test_fortify/read_overflow-memchr.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memchr(small, 0x7A, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/read_overflow-memchr_inv.c b/lib/test_fortify/read_overflow-memchr_inv.c
new file mode 100644
index 000000000000..b26e1f1bc217
--- /dev/null
+++ b/lib/test_fortify/read_overflow-memchr_inv.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memchr_inv(small, 0x7A, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/read_overflow-memcmp.c b/lib/test_fortify/read_overflow-memcmp.c
new file mode 100644
index 000000000000..d5d301ff64ef
--- /dev/null
+++ b/lib/test_fortify/read_overflow-memcmp.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memcmp(small, large, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/read_overflow-memscan.c b/lib/test_fortify/read_overflow-memscan.c
new file mode 100644
index 000000000000..c1a97f2df0f0
--- /dev/null
+++ b/lib/test_fortify/read_overflow-memscan.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memscan(small, 0x7A, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/read_overflow2-memcmp.c b/lib/test_fortify/read_overflow2-memcmp.c
new file mode 100644
index 000000000000..c6091e640f76
--- /dev/null
+++ b/lib/test_fortify/read_overflow2-memcmp.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memcmp(large, small, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/read_overflow2-memcpy.c b/lib/test_fortify/read_overflow2-memcpy.c
new file mode 100644
index 000000000000..07b62e56cf16
--- /dev/null
+++ b/lib/test_fortify/read_overflow2-memcpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memcpy(large, instance.buf, sizeof(large))
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/read_overflow2-memmove.c b/lib/test_fortify/read_overflow2-memmove.c
new file mode 100644
index 000000000000..34edfab040a3
--- /dev/null
+++ b/lib/test_fortify/read_overflow2-memmove.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memmove(large, instance.buf, sizeof(large))
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/test_fortify.h b/lib/test_fortify/test_fortify.h
new file mode 100644
index 000000000000..e1dfe64d79a3
--- /dev/null
+++ b/lib/test_fortify/test_fortify.h
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+void do_fortify_tests(void);
+
+#define __BUF_SMALL	16
+#define __BUF_LARGE	32
+struct fortify_object {
+	int a;
+	char buf[__BUF_SMALL];
+	int c;
+};
+
+#define LITERAL_SMALL "AAAAAAAAAAAAAAA"
+#define LITERAL_LARGE "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+const char small_src[__BUF_SMALL] = LITERAL_SMALL;
+const char large_src[__BUF_LARGE] = LITERAL_LARGE;
+
+char small[__BUF_SMALL];
+char large[__BUF_LARGE];
+struct fortify_object instance;
+size_t size;
+
+void do_fortify_tests(void)
+{
+	/* Normal initializations. */
+	memset(&instance, 0x32, sizeof(instance));
+	memset(small, 0xA5, sizeof(small));
+	memset(large, 0x5A, sizeof(large));
+
+	TEST;
+}
diff --git a/lib/test_fortify/write_overflow-memcpy.c b/lib/test_fortify/write_overflow-memcpy.c
new file mode 100644
index 000000000000..3b3984e428fb
--- /dev/null
+++ b/lib/test_fortify/write_overflow-memcpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memcpy(instance.buf, large_src, sizeof(large_src))
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-memmove.c b/lib/test_fortify/write_overflow-memmove.c
new file mode 100644
index 000000000000..640437c3b3e0
--- /dev/null
+++ b/lib/test_fortify/write_overflow-memmove.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memmove(instance.buf, large_src, sizeof(large_src))
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-memset.c b/lib/test_fortify/write_overflow-memset.c
new file mode 100644
index 000000000000..36e34908cfb3
--- /dev/null
+++ b/lib/test_fortify/write_overflow-memset.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memset(instance.buf, 0x5A, sizeof(large_src))
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strcpy-lit.c b/lib/test_fortify/write_overflow-strcpy-lit.c
new file mode 100644
index 000000000000..51effb3e50f9
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strcpy-lit.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strcpy(small, LITERAL_LARGE)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strcpy.c b/lib/test_fortify/write_overflow-strcpy.c
new file mode 100644
index 000000000000..84f1c56a64c8
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strcpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strcpy(small, large_src)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strlcpy-src.c b/lib/test_fortify/write_overflow-strlcpy-src.c
new file mode 100644
index 000000000000..91bf83ebd34a
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strlcpy-src.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strlcpy(small, large_src, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strlcpy.c b/lib/test_fortify/write_overflow-strlcpy.c
new file mode 100644
index 000000000000..1883db7c0cd6
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strlcpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strlcpy(instance.buf, large_src, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strncpy-src.c b/lib/test_fortify/write_overflow-strncpy-src.c
new file mode 100644
index 000000000000..8dcfb8c788dd
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strncpy-src.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strncpy(small, large_src, sizeof(small) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strncpy.c b/lib/test_fortify/write_overflow-strncpy.c
new file mode 100644
index 000000000000..b85f079c815d
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strncpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strncpy(instance.buf, large_src, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow-strscpy.c b/lib/test_fortify/write_overflow-strscpy.c
new file mode 100644
index 000000000000..38feddf377dc
--- /dev/null
+++ b/lib/test_fortify/write_overflow-strscpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	strscpy(instance.buf, large_src, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh
new file mode 100644
index 000000000000..a6d63871738b
--- /dev/null
+++ b/scripts/test_fortify.sh
@@ -0,0 +1,59 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+set -e
+
+# Argument 1: Source file to build.
+IN="$1"
+shift
+# Extract just the filename for error messages below.
+FILE="${IN##*/}"
+# Extract the function name for error messages below.
+FUNC="${FILE#*-}"
+FUNC="${FUNC%%-*}"
+FUNC="${FUNC%%.*}"
+# Extract the symbol to test for in build/symbol test below.
+WANT="__${FILE%%-*}"
+
+# Argument 2: Where to write the build log.
+OUT="$1"
+shift
+TMP="${OUT}.tmp"
+
+# Argument 3: Path to "nm" tool.
+NM="$1"
+shift
+
+# Remaining arguments are: $(CC) $(c_flags)
+
+# Clean up temporary file at exit.
+__cleanup() {
+	rm -f "$TMP"
+}
+trap __cleanup EXIT
+
+status=
+# Attempt to build a source that is expected to fail with a specific warning.
+if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then
+	# If the build succeeds, either the test has failed or the the
+	# warning may only happen at link time (Clang). In that case,
+	# make sure the expected symbol is unresolved in the symbol list.
+	# If so, FORTIFY is working for this case.
+	if ! $NM -A "$OUT".o | grep -m1 "\bU ${WANT}$" >>"$TMP" ; then
+		status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN"
+	fi
+else
+	# If the build failed, check for the warning in the stderr (gcc).
+	if ! grep -q -m1 "error:.*\b${WANT}'" "$TMP" ; then
+		status="warning: unsafe ${FUNC}() usage lacked '$WANT' warning in $IN"
+	fi
+fi
+
+if [ -n "$status" ]; then
+	# Report on failure results, including compilation warnings.
+	echo "$status" | tee "$OUT" >&2
+	cat "$TMP" | tee -a "$OUT" >&2
+else
+	# Report on good results, and save any compilation output to log.
+	echo "ok: unsafe ${FUNC}() usage correctly detected with '$WANT' in $IN" >"$OUT"
+	cat "$TMP" >>"$OUT"
+fi
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 33/63] lib: Introduce CONFIG_TEST_MEMCPY
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (31 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 32/63] fortify: Add compile-time FORTIFY_SOURCE tests Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 34/63] fortify: Detect struct member overflows in memcpy() at compile-time Kees Cook
                   ` (29 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Before changing anything about memcpy(), memmove(), and memset(), add
run-time tests to check basic behaviors for any regressions.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 lib/Kconfig.debug |   7 ++
 lib/Makefile      |   1 +
 lib/test_memcpy.c | 264 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 272 insertions(+)
 create mode 100644 lib/test_memcpy.c

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 139d362daa32..db2e8ffa6049 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2476,6 +2476,13 @@ config RATIONAL_KUNIT_TEST
 
 	  If unsure, say N.
 
+config MEMCPY_KUNIT_TEST
+	tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Builds unit tests for memcpy(), memmove(), and memset() functions.
+
 config TEST_UDELAY
 	tristate "udelay test driver"
 	help
diff --git a/lib/Makefile b/lib/Makefile
index bd17c2bf43e1..8a4c8bdb38a2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
 obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
 obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o
+obj-$(CONFIG_TEST_MEMCPY) += test_memcpy.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_SORT) += test_sort.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
diff --git a/lib/test_memcpy.c b/lib/test_memcpy.c
new file mode 100644
index 000000000000..be192b8e82b7
--- /dev/null
+++ b/lib/test_memcpy.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for memcpy(), memmove(), and memset().
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+struct some_bytes {
+	union {
+		u8 data[32];
+		struct {
+			u32 one;
+			u16 two;
+			u8  three;
+			/* 1 byte hole */
+			u32 four[4];
+		};
+	};
+};
+
+#define check(instance, v) do {	\
+	int i;	\
+	BUILD_BUG_ON(sizeof(instance.data) != 32);	\
+	for (i = 0; i < sizeof(instance.data); i++) {	\
+		KUNIT_ASSERT_EQ_MSG(test, instance.data[i], v, \
+			"line %d: '%s' not initialized to 0x%02x @ %d (saw 0x%02x)\n", \
+			__LINE__, #instance, v, i, instance.data[i]);	\
+	}	\
+} while (0)
+
+#define compare(name, one, two) do { \
+	int i; \
+	BUILD_BUG_ON(sizeof(one) != sizeof(two)); \
+	for (i = 0; i < sizeof(one); i++) {	\
+		KUNIT_EXPECT_EQ_MSG(test, one.data[i], two.data[i], \
+			"line %d: %s.data[%d] (0x%02x) != %s.data[%d] (0x%02x)\n", \
+			__LINE__, #one, i, one.data[i], #two, i, two.data[i]); \
+	}	\
+	kunit_info(test, "ok: " TEST_OP "() " name "\n");	\
+} while (0)
+
+static void memcpy_test(struct kunit *test)
+{
+#define TEST_OP "memcpy"
+	struct some_bytes control = {
+		.data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			},
+	};
+	struct some_bytes zero = { };
+	struct some_bytes middle = {
+		.data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00,
+			  0x00, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			},
+	};
+	struct some_bytes three = {
+		.data = { 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			},
+	};
+	struct some_bytes dest = { };
+	int count;
+	u8 *ptr;
+
+	/* Verify static initializers. */
+	check(control, 0x20);
+	check(zero, 0);
+	compare("static initializers", dest, zero);
+
+	/* Verify assignment. */
+	dest = control;
+	compare("direct assignment", dest, control);
+
+	/* Verify complete overwrite. */
+	memcpy(dest.data, zero.data, sizeof(dest.data));
+	compare("complete overwrite", dest, zero);
+
+	/* Verify middle overwrite. */
+	dest = control;
+	memcpy(dest.data + 12, zero.data, 7);
+	compare("middle overwrite", dest, middle);
+
+	/* Verify argument side-effects aren't repeated. */
+	dest = control;
+	ptr = dest.data;
+	count = 1;
+	memcpy(ptr++, zero.data, count++);
+	ptr += 8;
+	memcpy(ptr++, zero.data, count++);
+	compare("argument side-effects", dest, three);
+#undef TEST_OP
+}
+
+static void memmove_test(struct kunit *test)
+{
+#define TEST_OP "memmove"
+	struct some_bytes control = {
+		.data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes zero = { };
+	struct some_bytes middle = {
+		.data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00,
+			  0x00, 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes five = {
+		.data = { 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x00, 0x00, 0x00, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes overlap = {
+		.data = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+			  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes overlap_expected = {
+		.data = { 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x07,
+			  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes dest = { };
+	int count;
+	u8 *ptr;
+
+	/* Verify static initializers. */
+	check(control, 0x99);
+	check(zero, 0);
+	compare("static initializers", zero, dest);
+
+	/* Verify assignment. */
+	dest = control;
+	compare("direct assignment", dest, control);
+
+	/* Verify complete overwrite. */
+	memmove(dest.data, zero.data, sizeof(dest.data));
+	compare("complete overwrite", dest, zero);
+
+	/* Verify middle overwrite. */
+	dest = control;
+	memmove(dest.data + 12, zero.data, 7);
+	compare("middle overwrite", dest, middle);
+
+	/* Verify argument side-effects aren't repeated. */
+	dest = control;
+	ptr = dest.data;
+	count = 2;
+	memmove(ptr++, zero.data, count++);
+	ptr += 9;
+	memmove(ptr++, zero.data, count++);
+	compare("argument side-effects", dest, five);
+
+	/* Verify overlapping overwrite is correct. */
+	ptr = &overlap.data[2];
+	memmove(ptr, overlap.data, 5);
+	compare("overlapping write", overlap, overlap_expected);
+#undef TEST_OP
+}
+
+static void memset_test(struct kunit *test)
+{
+#define TEST_OP "memset"
+	struct some_bytes control = {
+		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			},
+	};
+	struct some_bytes complete = {
+		.data = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			},
+	};
+	struct some_bytes middle = {
+		.data = { 0x30, 0x30, 0x30, 0x30, 0x31, 0x31, 0x31, 0x31,
+			  0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
+			  0x31, 0x31, 0x31, 0x31, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			},
+	};
+	struct some_bytes three = {
+		.data = { 0x60, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x61, 0x61, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			},
+	};
+	struct some_bytes dest = { };
+	int count, value;
+	u8 *ptr;
+
+	/* Verify static initializers. */
+	check(control, 0x30);
+	check(dest, 0);
+
+	/* Verify assignment. */
+	dest = control;
+	compare("direct assignment", dest, control);
+
+	/* Verify complete overwrite. */
+	memset(dest.data, 0xff, sizeof(dest.data));
+	compare("complete overwrite", dest, complete);
+
+	/* Verify middle overwrite. */
+	dest = control;
+	memset(dest.data + 4, 0x31, 16);
+	compare("middle overwrite", dest, middle);
+
+	/* Verify argument side-effects aren't repeated. */
+	dest = control;
+	ptr = dest.data;
+	value = 0x60;
+	count = 1;
+	memset(ptr++, value++, count++);
+	ptr += 8;
+	memset(ptr++, value++, count++);
+	compare("argument side-effects", dest, three);
+#undef TEST_OP
+}
+
+static struct kunit_case memcpy_test_cases[] = {
+	KUNIT_CASE(memset_test),
+	KUNIT_CASE(memcpy_test),
+	KUNIT_CASE(memmove_test),
+	{}
+};
+
+static struct kunit_suite memcpy_test_suite = {
+	.name = "memcpy-test",
+	.test_cases = memcpy_test_cases,
+};
+kunit_test_suite(memcpy_test_suite);
+
+MODULE_LICENSE("GPL");
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 34/63] fortify: Detect struct member overflows in memcpy() at compile-time
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (32 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 33/63] lib: Introduce CONFIG_TEST_MEMCPY Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 35/63] fortify: Detect struct member overflows in memmove() " Kees Cook
                   ` (28 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

memcpy() is dead; long live memcpy()

tl;dr: In order to eliminate a large class of common buffer overflow
flaws that continue to persist in the kernel, have memcpy() (under
CONFIG_FORTIFY_SOURCE) perform bounds checking of the destination struct
member when they have a known size. This would have caught all of the
memcpy()-related buffer write overflow flaws identified in at least the
last three years.

Background and analysis:

While stack-based buffer overflow flaws are largely mitigated by stack
canaries (and similar) features, heap-based buffer overflow flaws continue
to regularly appear in the kernel. Many classes of heap buffer overflows
are mitigated by FORTIFY_SOURCE when using the strcpy() family of
functions, but a significant number remain exposed through the memcpy()
family of functions.

At its core, FORTIFY_SOURCE uses the compiler's __builtin_object_size()
internal[0] to determine the available size at a target address based on
the compile-time known structure layout details. It operates in two
modes: outer bounds (0) and inner bounds (1). In mode 0, the size of the
enclosing structure is used. In mode 1, the size of the specific field
is used. For example:

	struct object {
		u16 scalar1;	/* 2 bytes */
		char array[6];	/* 6 bytes */
		u64 scalar2;	/* 8 bytes */
		u32 scalar3;	/* 4 bytes */
		u32 scalar4;	/* 4 bytes */
	} instance;

__builtin_object_size(instance.array, 0) == 22, since the remaining size
of the enclosing structure starting from "array" is 22 bytes (6 + 8 +
4 + 4).

__builtin_object_size(instance.array, 1) == 6, since the remaining size
of the specific field "array" is 6 bytes.

The initial implementation of FORTIFY_SOURCE used mode 0 because there
were many cases of both strcpy() and memcpy() functions being used to
write (or read) across multiple fields in a structure. For example,
it would catch this, which is writing 2 bytes beyond the end of
"instance":

	memcpy(&instance.array, data, 24);

While this didn't protect against overwriting adjacent fields in a given
structure, it would at least stop overflows from reaching beyond the
end of the structure into neighboring memory, and provided a meaningful
mitigation of a subset of buffer overflow flaws. However, many desirable
targets remain within the enclosing structure (for example function
pointers).

As it happened, there were very few cases of strcpy() family functions
intentionally writing beyond the end of a string buffer. Once all known
cases were removed from the kernel, the strcpy() family was tightened[1]
to use mode 1, providing greater mitigation coverage.

What remains is switching memcpy() to mode 1 as well, but making the
switch is much more difficult because of how frustrating it can be to
find existing "normal" uses of memcpy() that expect to write (or read)
across multiple fields. The root cause of the problem is that the C
language lacks a common pattern to indicate the intent of an author's
use of memcpy(), and is further complicated by the available compile-time
and run-time mitigation behaviors.

The FORTIFY_SOURCE mitigation comes in two halves: the compile-time half,
when both the buffer size _and_ the length of the copy is known, and the
run-time half, when only the buffer size is known. If neither size is
known, there is no bounds checking possible. At compile-time when the
compiler sees that a length will always exceed a known buffer size,
a warning can be deterministically emitted. For the run-time half,
the length is tested against the known size of the buffer, and the
overflowing operation is detected. (The performance overhead for these
tests is virtually zero.)

It is relatively easy to find compile-time false-positives since a warning
is always generated. Fixing the false positives, however, can be very
time-consuming as there are hundreds of instances. While it's possible
some over-read conditions could lead to kernel memory exposures, the bulk
of the risk comes from the run-time flaws where the length of a write
may end up being attacker-controlled and lead to an overflow.

Many of the compile-time false-positives take a form similar to this:

	memcpy(&instance.scalar2, data, sizeof(instance.scalar2) +
					sizeof(instance.scalar3));

and the run-time ones are similar, but lack a constant expression for the
size of the copy:

	memcpy(instance.array, data, length);

The former is meant to cover multiple fields (though its style has been
frowned upon more recently), but has been technically legal. Both lack
any expressivity in the C language about the author's _intent_ in a way
that a compiler can check when the length isn't known at compile time.
A comment doesn't work well because what's needed is something a compiler
can directly reason about. Is a given memcpy() call expected to overflow
into neighbors? Is it not? By using the new struct_group() macro, this
intent can be much more easily encoded.

It is not as easy to find the run-time false-positives since the code path
to exercise a seemingly out-of-bounds condition that is actually expected
may not be trivially reachable. Tightening the restrictions to block an
operation for a false positive will either potentially create a greater
flaw (if a copy is truncated by the mitigation), or destabilize the kernel
(e.g. with a BUG()), making things completely useless for the end user.

As a result, tightening the memcpy() restriction (when there is a
reasonable level of uncertainty of the number of false positives), needs
to first WARN() with no truncation. (Though any sufficiently paranoid
end-user can always opt to set the panic_on_warn=1 sysctl.) Once enough
development time has passed, the mitigation can be further intensified.

Given the potential frustrations of weeding out all the false positives
when tightening the run-time checks, it is reasonable to wonder if these
changes would actually add meaningful protection. Looking at just the
last three years, there are 23 identified flaws with a CVE that mention
"buffer overflow", and 11 are memcpy()-related buffer overflows.

(For the remaining 12: 7 are array index overflows that would be
mitigated by systems built with CONFIG_UBSAN_BOUNDS=y: CVE-2019-0145,
CVE-2019-14835, CVE-2019-14896, CVE-2019-14897, CVE-2019-14901,
CVE-2019-17666, CVE-2021-28952. 2 are miscalculated allocation
sizes which could be mitigated with memory tagging: CVE-2019-16746,
CVE-2019-2181. 1 is an iovec buffer bug maybe mitigated by memory tagging:
CVE-2020-10742. 1 is a type confusion bug mitigated by stack canaries:
CVE-2020-10942. 1 is a string handling logic bug with no mitigation I'm
aware of: CVE-2021-28972.)

At my last count on an x86_64 allmodconfig build, there are 25,018 calls
to memcpy(). With callers instrumented to report all places where the
buffer size is known but the length remains unknown (i.e. a run-time
bounds check is added), we can count how many new run-time bounds checks
are added when the destination and source arguments of memcpy() are
changed to use "mode 1" bounds checking: 1540. In addition, there were
146 new compile-time warnings to evaluate and fix.

With this it's also possible to compare the places where the known 11
memcpy() flaw overflows happened against the resulting list of potential
new bounds checks, as a measure of potential efficacy of the tightened
mitigation. Much to my surprise, horror, and delight, all 11 flaws would
have been detected by the newly added run-time bounds checks, making this
a distinctly clear mitigation improvement: 100% coverage for memcpy()
flaws, with a possible 2 orders of magnitude gain in coverage over
existing but undiscovered run-time dynamic length flaws, against only 6%
of all callers maybe gaining a false positive run-time check, with fewer
than 150 new compile-time instances needing evaluation.

Specifically these would have been mitigated:
CVE-2020-24490 https://git.kernel.org/linus/a2ec905d1e160a33b2e210e45ad30445ef26ce0e
CVE-2020-12654 https://git.kernel.org/linus/3a9b153c5591548612c3955c9600a98150c81875
CVE-2020-12653 https://git.kernel.org/linus/b70261a288ea4d2f4ac7cd04be08a9f0f2de4f4d
CVE-2019-14895 https://git.kernel.org/linus/3d94a4a8373bf5f45cf5f939e88b8354dbf2311b
CVE-2019-14816 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-14815 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-14814 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-10126 https://git.kernel.org/linus/69ae4f6aac1578575126319d3f55550e7e440449
CVE-2019-9500  https://git.kernel.org/linus/1b5e2423164b3670e8bc9174e4762d297990deff
no-CVE-yet     https://git.kernel.org/linus/130f634da1af649205f4a3dd86cbe5c126b57914
no-CVE-yet     https://git.kernel.org/linus/d10a87a3535cce2b890897914f5d0d83df669c63

To accelerate the review of potential run-time false positives, it's
also worth noting that it is possible to partially automate checking
by examining the memcpy() buffer argument to check for the destination
struct member having a neighboring array member. It is reasonable to
expect that the vast majority of run-time false positives would look like
the already evaluated and fixed compile-time false positives, where the
most common pattern is neighboring arrays. (And, FWIW, several of the
compile-time fixes were actual bugs.)

Implementation:

Tighten the memcpy() destination buffer size checking to use the actual
("mode 1") target buffer size as the bounds check instead of their
enclosing structure's ("mode 0") size. Use a common inline for memcpy()
(and memmove() in a following patch), since all the tests are the
same. All new cross-field memcpy() uses must use the struct_group() macro
or similar to target a specific range of fields, so that FORTIFY_SOURCE
can reason about the size and safety of the copy.

For now, cross-member "mode 1" read detection at compile-time will be
limited to W=1 builds, since it is, unfortunately, very common. As the
priority is solving write overflows, read overflows can be part of the
next phase.

For run-time, the "mode 0" size checking and mitigation is left unchanged,
with "mode 1" to be added in stages. In this patch, no new run-time
checks are added. Future patches will first bounds-check writes,
and only perform a WARN() for now. This way any missed run-time false
positives can be flushed out over the coming several development cycles,
but system builders who have tested their workloads to be WARN()-free
can enable the panic_on_warn=1 sysctl to immediately gain a mitigation
against this class of buffer overflows. Once that is under way, run-time
bounds-checking of reads can be similarly added.

Related classes of flaws that remain unmitigated:

- memcpy() with raw pointers (e.g. void *, char *, etc) have no good
  mitigation beyond memory tagging (and even that would only protect
  against inter-object overflow, not intra-object neighboring field
  overflows). Some kind of "fat pointer" solution is likely needed to
  gain proper size-of-buffer awareness.

- type confusion where a higher level type's allocation size does
  not match the resulting cast type eventually passed to a deeper
  memcpy() call where the compiler cannot see the true type. In
  theory, greater static analysis could catch these.

[0] https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
[1] https://git.kernel.org/linus/6a39e62abbafd1d58d1722f40c7d26ef379c6a2f

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h                | 109 ++++++++++++++++--
 include/linux/string.h                        |   5 +-
 lib/Makefile                                  |   3 +-
 lib/string_helpers.c                          |   6 +
 .../read_overflow2_field-memcpy.c             |   5 +
 .../write_overflow_field-memcpy.c             |   5 +
 6 files changed, 118 insertions(+), 15 deletions(-)
 create mode 100644 lib/test_fortify/read_overflow2_field-memcpy.c
 create mode 100644 lib/test_fortify/write_overflow_field-memcpy.c

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index e232a63fd826..25943442f532 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -8,7 +8,9 @@
 void fortify_panic(const char *name) __noreturn __cold;
 void __read_overflow(void) __compiletime_error("detected read beyond size of object (1st parameter)");
 void __read_overflow2(void) __compiletime_error("detected read beyond size of object (2nd parameter)");
+void __read_overflow2_field(size_t avail, size_t wanted) __compiletime_warning("detected read beyond size of field (2nd parameter); maybe use struct_group()?");
 void __write_overflow(void) __compiletime_error("detected write beyond size of object (1st parameter)");
+void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning("detected write beyond size of field (1st parameter); maybe use struct_group()?");
 
 #define __compiletime_strlen(p)	({		\
 	size_t ret = (size_t)-1;			\
@@ -207,22 +209,105 @@ __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
 	return __underlying_memset(p, c, size);
 }
 
-__FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
+/*
+ * To make sure the compiler can enforce protection against buffer overflows,
+ * memcpy(), memmove(), and memset() must not be used beyond individual
+ * struct members. If you need to copy across multiple members, please use
+ * struct_group() to create a named mirror of an anonymous struct union.
+ * (e.g. see struct sk_buff.)
+ *
+ * Mitigation coverage
+ *					Bounds checking at:
+ *					+-------+-------+-------+-------+
+ *					| Compile time  | Run time      |
+ * memcpy() argument sizes:		| write | read  | write | read  |
+ *					+-------+-------+-------+-------+
+ * memcpy(known,   known,   constant)	|   y   |   y   |  n/a  |  n/a  |
+ * memcpy(unknown, known,   constant)	|   n   |   y   |   V   |  n/a  |
+ * memcpy(known,   unknown, constant)	|   y   |   n   |  n/a  |   V   |
+ * memcpy(unknown, unknown, constant)	|   n   |   n   |   V   |   V   |
+ * memcpy(known,   known,   dynamic)	|   n   |   n   |   b   |   B   |
+ * memcpy(unknown, known,   dynamic)	|   n   |   n   |   V   |   B   |
+ * memcpy(known,   unknown, dynamic)	|   n   |   n   |   b   |   V   |
+ * memcpy(unknown, unknown, dynamic)	|   n   |   n   |   V   |   V   |
+ *					+-------+-------+-------+-------+
+ *
+ * y = deterministic compile-time bounds checking
+ * n = cannot do deterministic compile-time bounds checking
+ * n/a = no run-time bounds checking needed since compile-time deterministic
+ * b = perform run-time bounds checking
+ * B = can perform run-time bounds checking, but current unenforced
+ * V = vulnerable to run-time overflow
+ *
+ */
+__FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size,
+					 const size_t p_size,
+					 const size_t q_size,
+					 const size_t p_size_field,
+					 const size_t q_size_field,
+					 const char *func)
 {
-	size_t p_size = __builtin_object_size(p, 0);
-	size_t q_size = __builtin_object_size(q, 0);
-
 	if (__builtin_constant_p(size)) {
-		if (p_size < size)
+		/*
+		 * Length argument is a constant expression, so we
+		 * can perform compile-time bounds checking where
+		 * buffer sizes are known.
+		 */
+
+		/* Error when size is larger than enclosing struct. */
+		if (p_size > p_size_field && p_size < size)
 			__write_overflow();
-		if (q_size < size)
+		if (q_size > q_size_field && q_size < size)
 			__read_overflow2();
+
+		/* Warn when write size argument larger than dest field. */
+		if (p_size_field < size)
+			__write_overflow_field(p_size_field, size);
+		/*
+		 * Warn for source field over-read when building with W=1
+		 * or when an over-write happened, so both can be fixed at
+		 * the same time.
+		 */
+		if ((IS_ENABLED(KBUILD_EXTRA_WARN1) || p_size_field < size) &&
+		    q_size_field < size)
+			__read_overflow2_field(q_size_field, size);
 	}
-	if (p_size < size || q_size < size)
-		fortify_panic(__func__);
-	return __underlying_memcpy(p, q, size);
+	/*
+	 * At this point, length argument may not be a constant expression,
+	 * so run-time bounds checking can be done where buffer sizes are
+	 * known. (This is not an "else" because the above checks may only
+	 * be compile-time warnings, and we want to still warn for run-time
+	 * overflows.)
+	 */
+
+	/*
+	 * Always stop accesses beyond the struct that contains the
+	 * field, when the buffer's remaining size is known.
+	 * (The -1 test is to optimize away checks where the buffer
+	 * lengths are unknown.)
+	 */
+	if ((p_size != (size_t)(-1) && p_size < size) ||
+	    (q_size != (size_t)(-1) && q_size < size))
+		fortify_panic(func);
 }
 
+#define __fortify_memcpy_chk(p, q, size, p_size, q_size,		\
+			     p_size_field, q_size_field, op) ({		\
+	size_t __fortify_size = (size_t)(size);				\
+	fortify_memcpy_chk(__fortify_size, p_size, q_size,		\
+			   p_size_field, q_size_field, #op);		\
+	__underlying_##op(p, q, __fortify_size);			\
+})
+
+/*
+ * __builtin_object_size() must be captured here to avoid evaluating argument
+ * side-effects further into the macro layers.
+ */
+#define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,			\
+		__builtin_object_size(p, 0), __builtin_object_size(q, 0), \
+		__builtin_object_size(p, 1), __builtin_object_size(q, 1), \
+		memcpy)
+
 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
 {
 	size_t p_size = __builtin_object_size(p, 0);
@@ -302,13 +387,14 @@ __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
 	return __real_kmemdup(p, size, gfp);
 }
 
-/* defined after fortified strlen and memcpy to reuse them */
+/* Defined after fortified strlen to reuse it. */
 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 {
 	size_t p_size = __builtin_object_size(p, 1);
 	size_t q_size = __builtin_object_size(q, 1);
 	size_t size;
 
+	/* If neither buffer size is known, immediately give up. */
 	if (p_size == (size_t)-1 && q_size == (size_t)-1)
 		return __underlying_strcpy(p, q);
 	size = strlen(q) + 1;
@@ -318,14 +404,13 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 	/* Run-time check for dynamic size overflow. */
 	if (p_size < size)
 		fortify_panic(__func__);
-	memcpy(p, q, size);
+	__underlying_memcpy(p, q, size);
 	return p;
 }
 
 /* Don't use these outside the FORITFY_SOURCE implementation */
 #undef __underlying_memchr
 #undef __underlying_memcmp
-#undef __underlying_memcpy
 #undef __underlying_memmove
 #undef __underlying_memset
 #undef __underlying_strcat
diff --git a/include/linux/string.h b/include/linux/string.h
index 9473f81b9db2..cbe889e404e2 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -261,8 +261,9 @@ static inline const char *kbasename(const char *path)
  * @count: The number of bytes to copy
  * @pad: Character to use for padding if space is left in destination.
  */
-static inline void memcpy_and_pad(void *dest, size_t dest_len,
-				  const void *src, size_t count, int pad)
+static __always_inline void memcpy_and_pad(void *dest, size_t dest_len,
+					   const void *src, size_t count,
+					   int pad)
 {
 	if (dest_len > count) {
 		memcpy(dest, src, count);
diff --git a/lib/Makefile b/lib/Makefile
index 8a4c8bdb38a2..ff80f09947c2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -370,7 +370,8 @@ TEST_FORTIFY_LOG = test_fortify.log
 quiet_cmd_test_fortify = TEST    $@
       cmd_test_fortify = $(CONFIG_SHELL) $(srctree)/scripts/test_fortify.sh \
 			$< $@ "$(NM)" $(CC) $(c_flags) \
-			$(call cc-disable-warning,fortify-source)
+			$(call cc-disable-warning,fortify-source) \
+			-DKBUILD_EXTRA_WARN1
 
 targets += $(TEST_FORTIFY_LOGS)
 clean-files += $(TEST_FORTIFY_LOGS)
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index faa9d8e4e2c5..961636c120b1 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -884,6 +884,12 @@ char *strreplace(char *s, char old, char new)
 EXPORT_SYMBOL(strreplace);
 
 #ifdef CONFIG_FORTIFY_SOURCE
+/* These are placeholders for fortify compile-time warnings. */
+void __read_overflow2_field(size_t avail, size_t wanted) { }
+EXPORT_SYMBOL(__read_overflow2_field);
+void __write_overflow_field(size_t avail, size_t wanted) { }
+EXPORT_SYMBOL(__write_overflow_field);
+
 void fortify_panic(const char *name)
 {
 	pr_emerg("detected buffer overflow in %s\n", name);
diff --git a/lib/test_fortify/read_overflow2_field-memcpy.c b/lib/test_fortify/read_overflow2_field-memcpy.c
new file mode 100644
index 000000000000..de9569266223
--- /dev/null
+++ b/lib/test_fortify/read_overflow2_field-memcpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memcpy(large, instance.buf, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow_field-memcpy.c b/lib/test_fortify/write_overflow_field-memcpy.c
new file mode 100644
index 000000000000..28cc81058dd3
--- /dev/null
+++ b/lib/test_fortify/write_overflow_field-memcpy.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memcpy(instance.buf, large, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 35/63] fortify: Detect struct member overflows in memmove() at compile-time
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (33 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 34/63] fortify: Detect struct member overflows in memcpy() at compile-time Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 36/63] scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp Kees Cook
                   ` (27 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

As done for memcpy(), also update memmove() to use the same tightened
compile-time checks under CONFIG_FORTIFY_SOURCE.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/boot/compressed/misc.c               |  3 ++-
 arch/x86/lib/memcpy_32.c                      |  1 +
 include/linux/fortify-string.h                | 21 ++++---------------
 .../read_overflow2_field-memmove.c            |  5 +++++
 .../write_overflow_field-memmove.c            |  5 +++++
 5 files changed, 17 insertions(+), 18 deletions(-)
 create mode 100644 lib/test_fortify/read_overflow2_field-memmove.c
 create mode 100644 lib/test_fortify/write_overflow_field-memmove.c

diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 743f13ea25c1..83ff4354970e 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -34,10 +34,11 @@
  * try to define their own functions if these are not defined as macros.
  */
 #define memzero(s, n)	memset((s), 0, (n))
+#ifndef memmove
 #define memmove		memmove
-
 /* Functions used by the included decompressor code below. */
 void *memmove(void *dest, const void *src, size_t n);
+#endif
 
 /*
  * This is set up by the setup-routine at boot-time
diff --git a/arch/x86/lib/memcpy_32.c b/arch/x86/lib/memcpy_32.c
index e565d1c9019e..f19b7fd07f04 100644
--- a/arch/x86/lib/memcpy_32.c
+++ b/arch/x86/lib/memcpy_32.c
@@ -4,6 +4,7 @@
 
 #undef memcpy
 #undef memset
+#undef memmove
 
 __visible void *memcpy(void *to, const void *from, size_t n)
 {
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 25943442f532..0120d463ba33 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -307,22 +307,10 @@ __FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size,
 		__builtin_object_size(p, 0), __builtin_object_size(q, 0), \
 		__builtin_object_size(p, 1), __builtin_object_size(q, 1), \
 		memcpy)
-
-__FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
-{
-	size_t p_size = __builtin_object_size(p, 0);
-	size_t q_size = __builtin_object_size(q, 0);
-
-	if (__builtin_constant_p(size)) {
-		if (p_size < size)
-			__write_overflow();
-		if (q_size < size)
-			__read_overflow2();
-	}
-	if (p_size < size || q_size < size)
-		fortify_panic(__func__);
-	return __underlying_memmove(p, q, size);
-}
+#define memmove(p, q, s)  __fortify_memcpy_chk(p, q, s,			\
+		__builtin_object_size(p, 0), __builtin_object_size(q, 0), \
+		__builtin_object_size(p, 1), __builtin_object_size(q, 1), \
+		memmove)
 
 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
@@ -411,7 +399,6 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 /* Don't use these outside the FORITFY_SOURCE implementation */
 #undef __underlying_memchr
 #undef __underlying_memcmp
-#undef __underlying_memmove
 #undef __underlying_memset
 #undef __underlying_strcat
 #undef __underlying_strcpy
diff --git a/lib/test_fortify/read_overflow2_field-memmove.c b/lib/test_fortify/read_overflow2_field-memmove.c
new file mode 100644
index 000000000000..6cc2724c8f62
--- /dev/null
+++ b/lib/test_fortify/read_overflow2_field-memmove.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memmove(large, instance.buf, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
diff --git a/lib/test_fortify/write_overflow_field-memmove.c b/lib/test_fortify/write_overflow_field-memmove.c
new file mode 100644
index 000000000000..377fcf9bb2fd
--- /dev/null
+++ b/lib/test_fortify/write_overflow_field-memmove.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memmove(instance.buf, large, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 36/63] scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (34 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 35/63] fortify: Detect struct member overflows in memmove() " Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 37/63] string.h: Introduce memset_after() for wiping trailing members/padding Kees Cook
                   ` (26 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Tyrel Datwyler, Michael Ellerman,
	Benjamin Herrenschmidt, Paul Mackerras, James E.J. Bottomley,
	Martin K. Petersen, linux-scsi, linuxppc-dev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Instead of writing beyond the end of evt_struct->iu.srp.cmd, target the
upper union (evt_struct->iu.srp) instead, as that's what is being wiped.

Cc: Tyrel Datwyler <tyreld@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/lkml/yq135rzp79c.fsf@ca-mkp.ca.oracle.com
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/lkml/6eae8434-e9a7-aa74-628b-b515b3695359@linux.ibm.com
---
 drivers/scsi/ibmvscsi/ibmvscsi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 50df7dd9cb91..ea8e01f49cba 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -1055,8 +1055,9 @@ static int ibmvscsi_queuecommand_lck(struct scsi_cmnd *cmnd,
 		return SCSI_MLQUEUE_HOST_BUSY;
 
 	/* Set up the actual SRP IU */
+	BUILD_BUG_ON(sizeof(evt_struct->iu.srp) != SRP_MAX_IU_LEN);
+	memset(&evt_struct->iu.srp, 0x00, sizeof(evt_struct->iu.srp));
 	srp_cmd = &evt_struct->iu.srp.cmd;
-	memset(srp_cmd, 0x00, SRP_MAX_IU_LEN);
 	srp_cmd->opcode = SRP_CMD;
 	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(srp_cmd->cdb));
 	int_to_scsilun(lun, &srp_cmd->lun);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 37/63] string.h: Introduce memset_after() for wiping trailing members/padding
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (35 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 36/63] scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 38/63] xfrm: Use memset_after() to clear padding Kees Cook
                   ` (25 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Steffen Klassert, Herbert Xu, David S. Miller,
	Jakub Kicinski, Andrew Morton, Francis Laniel, Vincenzo Frascino,
	Daniel Axtens, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

A common idiom in kernel code is to wipe the contents of a structure
after a given member. This is especially useful in places where there is
trailing padding. These open-coded cases are usually difficult to read
and very sensitive to struct layout changes. Introduce a new helper,
memset_after() that takes the target struct instance, the byte to write,
and the member name after which the zeroing should start.

Additionally adds memset_startat() for wiping trailing members _starting_
at a specific member instead of after a member, which is more readable
in certain circumstances, but doesn't include any preceding padding.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Francis Laniel <laniel_francis@privacyrequired.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/string.h | 29 +++++++++++++++++++++++++++++
 lib/test_memcpy.c      | 24 ++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/include/linux/string.h b/include/linux/string.h
index cbe889e404e2..fe56a1774207 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -272,6 +272,35 @@ static __always_inline void memcpy_and_pad(void *dest, size_t dest_len,
 		memcpy(dest, src, dest_len);
 }
 
+/**
+ * memset_after - Set a value after a struct member to the end of a struct
+ *
+ * @obj: Address of target struct instance
+ * @v: Byte value to repeatedly write
+ * @member: after which struct member to start writing bytes
+ *
+ * This is good for clearing padding following the given member.
+ */
+#define memset_after(obj, v, member) do {				\
+	memset((u8 *)(obj) + offsetofend(typeof(*(obj)), member), v,	\
+	       sizeof(*(obj)) - offsetofend(typeof(*(obj)), member));	\
+} while (0)
+
+/**
+ * memset_startat - Set a value starting at a member to the end of a struct
+ *
+ * @obj: Address of target struct instance
+ * @v: Byte value to repeatedly write
+ * @member: struct member to start writing at
+ *
+ * Note that if there is padding between the prior member and the target
+ * member, memset_after() should be used to clear the prior padding.
+ */
+#define memset_startat(obj, v, member) do {				\
+	memset((u8 *)(obj) + offsetof(typeof(*(obj)), member), v,	\
+	       sizeof(*(obj)) - offsetof(typeof(*(obj)), member));	\
+} while (0)
+
 /**
  * str_has_prefix - Test if a string has a given prefix
  * @str: The string to test
diff --git a/lib/test_memcpy.c b/lib/test_memcpy.c
index be192b8e82b7..50bc99552a17 100644
--- a/lib/test_memcpy.c
+++ b/lib/test_memcpy.c
@@ -215,6 +215,20 @@ static void memset_test(struct kunit *test)
 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
 			},
 	};
+	struct some_bytes after = {
+		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x72,
+			  0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72,
+			  0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72,
+			  0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72,
+			},
+	};
+	struct some_bytes startat = {
+		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79,
+			  0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79,
+			  0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79,
+			},
+	};
 	struct some_bytes dest = { };
 	int count, value;
 	u8 *ptr;
@@ -245,6 +259,16 @@ static void memset_test(struct kunit *test)
 	ptr += 8;
 	memset(ptr++, value++, count++);
 	compare("argument side-effects", dest, three);
+
+	/* Verify memset_after() */
+	dest = control;
+	memset_after(&dest, 0x72, three);
+	compare("memset_after()", dest, after);
+
+	/* Verify memset_startat() */
+	dest = control;
+	memset_startat(&dest, 0x79, four);
+	compare("memset_startat()", dest, startat);
 #undef TEST_OP
 }
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 38/63] xfrm: Use memset_after() to clear padding
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (36 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 37/63] string.h: Introduce memset_after() for wiping trailing members/padding Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 39/63] ipv6: Use memset_after() to zero rt6_info Kees Cook
                   ` (24 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Steffen Klassert, Herbert Xu, David S. Miller,
	Jakub Kicinski, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Clear trailing padding bytes using the new helper so that memset()
doesn't get confused about writing "past the end" of the last struct
member. There is no change to the resulting machine code.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/xfrm/xfrm_policy.c | 4 +---
 net/xfrm/xfrm_user.c   | 2 +-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 37d17a79617c..1a06585022ab 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2486,9 +2486,7 @@ static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
 	xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
 
 	if (likely(xdst)) {
-		struct dst_entry *dst = &xdst->u.dst;
-
-		memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
+		memset_after(xdst, 0, u.dst);
 	} else
 		xdst = ERR_PTR(-ENOBUFS);
 
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 03b66d154b2b..b7b986520dc7 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2912,7 +2912,7 @@ static int build_expire(struct sk_buff *skb, struct xfrm_state *x, const struct
 	copy_to_user_state(x, &ue->state);
 	ue->hard = (c->data.hard != 0) ? 1 : 0;
 	/* clear the padding bytes */
-	memset(&ue->hard + 1, 0, sizeof(*ue) - offsetofend(typeof(*ue), hard));
+	memset_after(ue, 0, hard);
 
 	err = xfrm_mark_put(skb, &x->mark);
 	if (err)
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 39/63] ipv6: Use memset_after() to zero rt6_info
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (37 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 38/63] xfrm: Use memset_after() to clear padding Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 40/63] netfilter: conntrack: Use memset_startat() to zero struct nf_conn Kees Cook
                   ` (23 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, David S. Miller, Hideaki YOSHIFUJI, David Ahern,
	Jakub Kicinski, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_after() to clear everything after the dst_entry member of
struct rt6_info.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/ipv6/route.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 6cf4bb89ca69..bd0ab3e436e7 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -327,9 +327,7 @@ static const struct rt6_info ip6_blk_hole_entry_template = {
 
 static void rt6_info_init(struct rt6_info *rt)
 {
-	struct dst_entry *dst = &rt->dst;
-
-	memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
+	memset_after(rt, 0, dst);
 	INIT_LIST_HEAD(&rt->rt6i_uncached);
 }
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 40/63] netfilter: conntrack: Use memset_startat() to zero struct nf_conn
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (38 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 39/63] ipv6: Use memset_after() to zero rt6_info Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 41/63] net: 802: Use memset_startat() to clear struct fields Kees Cook
                   ` (22 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Pablo Neira Ayuso, Jozsef Kadlecsik, Florian Westphal,
	David S. Miller, Jakub Kicinski, netfilter-devel, coreteam,
	netdev, Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() to avoid confusing memset() about writing beyond
the target struct member.

Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netfilter-devel@vger.kernel.org
Cc: coreteam@netfilter.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/netfilter/nf_conntrack_core.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index d31dbccbe7bd..060503230519 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1500,9 +1500,7 @@ __nf_conntrack_alloc(struct net *net,
 	ct->status = 0;
 	ct->timeout = 0;
 	write_pnet(&ct->ct_net, net);
-	memset(&ct->__nfct_init_offset, 0,
-	       offsetof(struct nf_conn, proto) -
-	       offsetof(struct nf_conn, __nfct_init_offset));
+	memset_after(ct, 0, __nfct_init_offset);
 
 	nf_ct_zone_add(ct, zone);
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 41/63] net: 802: Use memset_startat() to clear struct fields
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (39 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 40/63] netfilter: conntrack: Use memset_startat() to zero struct nf_conn Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 42/63] net: dccp: Use memset_startat() for TP zeroing Kees Cook
                   ` (21 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Jes Sorensen, David S. Miller, Jakub Kicinski,
	linux-hippi, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-hippi@sunsite.dk
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/802/hippi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/802/hippi.c b/net/802/hippi.c
index f80b33a8f7e0..6f71ffc8bdd1 100644
--- a/net/802/hippi.c
+++ b/net/802/hippi.c
@@ -65,7 +65,7 @@ static int hippi_header(struct sk_buff *skb, struct net_device *dev,
 	hip->le.src_addr_type	= 2;	/* 12 bit SC address */
 
 	memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
-	memset(&hip->le.reserved, 0, 16);
+	memset_startat(&hip->le, 0, reserved);
 
 	hip->snap.dsap		= HIPPI_EXTENDED_SAP;
 	hip->snap.ssap		= HIPPI_EXTENDED_SAP;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 42/63] net: dccp: Use memset_startat() for TP zeroing
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (40 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 41/63] net: 802: Use memset_startat() to clear struct fields Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 43/63] net: qede: Use memset_startat() for counters Kees Cook
                   ` (20 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, David S. Miller, Jakub Kicinski, dccp, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: dccp@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/dccp/trace.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/dccp/trace.h b/net/dccp/trace.h
index 5062421beee9..5a43b3508c7f 100644
--- a/net/dccp/trace.h
+++ b/net/dccp/trace.h
@@ -60,9 +60,7 @@ TRACE_EVENT(dccp_probe,
 			__entry->tx_t_ipi = hc->tx_t_ipi;
 		} else {
 			__entry->tx_s = 0;
-			memset(&__entry->tx_rtt, 0, (void *)&__entry->tx_t_ipi -
-			       (void *)&__entry->tx_rtt +
-			       sizeof(__entry->tx_t_ipi));
+			memset_startat(__entry, 0, tx_rtt);
 		}
 	),
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 43/63] net: qede: Use memset_startat() for counters
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (41 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 42/63] net: dccp: Use memset_startat() for TP zeroing Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status Kees Cook
                   ` (19 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Ariel Elior, GR-everest-linux-l2, David S. Miller,
	Jakub Kicinski, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

The old code was doing the wrong thing: it starts from the second member
and writes beyond int_info, clobbering qede_lock:

struct qede_dev {
	...
        struct qed_int_info             int_info;

        /* Smaller private variant of the RTNL lock */
        struct mutex                    qede_lock;
	...

struct qed_int_info {
        struct msix_entry       *msix;
        u8                      msix_cnt;

        /* This should be updated by the protocol driver */
        u8                      used_cnt;
};

Cc: Ariel Elior <aelior@marvell.com>
Cc: GR-everest-linux-l2@marvell.com
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/qlogic/qede/qede_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index d400e9b235bf..0ed9a0c8452c 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -2419,7 +2419,7 @@ static int qede_load(struct qede_dev *edev, enum qede_load_mode mode,
 	goto out;
 err4:
 	qede_sync_free_irqs(edev);
-	memset(&edev->int_info.msix_cnt, 0, sizeof(struct qed_int_info));
+	memset_startat(&edev->int_info, 0, msix_cnt);
 err3:
 	qede_napi_disable_remove(edev);
 err2:
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (42 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 43/63] net: qede: Use memset_startat() for counters Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  7:08   ` Johannes Berg
  2021-08-18  6:05 ` [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors Kees Cook
                   ` (18 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Johannes Berg, David S. Miller, Jakub Kicinski,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_after() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Additionally fix the common helper, ieee80211_tx_info_clear_status(),
which was not clearing ack_signal, but the open-coded versions
did. Johannes Berg points out this bug was introduced by commit
e3e1a0bcb3f1 ("mac80211: reduce IEEE80211_TX_MAX_RATES") but was harmless.

Also drops the associated unneeded BUILD_BUG_ON()s, and adds a note to
carl9170 about usage.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/ath/carl9170/tx.c   | 11 +++++------
 drivers/net/wireless/intersil/p54/txrx.c |  6 +-----
 include/net/mac80211.h                   |  7 +------
 3 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c
index 88444fe6d1c6..aa95d1a65882 100644
--- a/drivers/net/wireless/ath/carl9170/tx.c
+++ b/drivers/net/wireless/ath/carl9170/tx.c
@@ -275,12 +275,11 @@ static void carl9170_tx_release(struct kref *ref)
 	if (WARN_ON_ONCE(!ar))
 		return;
 
-	BUILD_BUG_ON(
-	    offsetof(struct ieee80211_tx_info, status.ack_signal) != 20);
-
-	memset(&txinfo->status.ack_signal, 0,
-	       sizeof(struct ieee80211_tx_info) -
-	       offsetof(struct ieee80211_tx_info, status.ack_signal));
+	/*
+	 * Should this call ieee80211_tx_info_clear_status() instead of clearing
+	 * manually? txinfo->status.rates do not seem to be used here.
+	 */
+	memset_after(&txinfo->status, 0, rates);
 
 	if (atomic_read(&ar->tx_total_queued))
 		ar->tx_schedule = true;
diff --git a/drivers/net/wireless/intersil/p54/txrx.c b/drivers/net/wireless/intersil/p54/txrx.c
index 873fea59894f..8414aa208655 100644
--- a/drivers/net/wireless/intersil/p54/txrx.c
+++ b/drivers/net/wireless/intersil/p54/txrx.c
@@ -431,11 +431,7 @@ static void p54_rx_frame_sent(struct p54_common *priv, struct sk_buff *skb)
 	 * Clear manually, ieee80211_tx_info_clear_status would
 	 * clear the counts too and we need them.
 	 */
-	memset(&info->status.ack_signal, 0,
-	       sizeof(struct ieee80211_tx_info) -
-	       offsetof(struct ieee80211_tx_info, status.ack_signal));
-	BUILD_BUG_ON(offsetof(struct ieee80211_tx_info,
-			      status.ack_signal) != 20);
+	memset_after(&info->status, 0, rates);
 
 	if (entry_hdr->flags & cpu_to_le16(P54_HDR_FLAG_DATA_ALIGN))
 		pad = entry_data->align[0];
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d8a1d09a2141..4c469b04de37 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1197,12 +1197,7 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
 	/* clear the rate counts */
 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++)
 		info->status.rates[i].count = 0;
-
-	BUILD_BUG_ON(
-	    offsetof(struct ieee80211_tx_info, status.ack_signal) != 20);
-	memset(&info->status.ampdu_ack_len, 0,
-	       sizeof(struct ieee80211_tx_info) -
-	       offsetof(struct ieee80211_tx_info, status.ampdu_ack_len));
+	memset_after(&info->status, 0, rates);
 }
 
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (43 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-19 13:19   ` Kalle Valo
  2021-08-18  6:05 ` [PATCH v2 46/63] iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl Kees Cook
                   ` (17 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Kalle Valo, David S. Miller, Jakub Kicinski, ath11k,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct. Additionally split up a later
field-spanning memset() so that memset() can reason about the size.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: ath11k@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/ath/ath11k/hal_rx.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/hal_rx.c b/drivers/net/wireless/ath/ath11k/hal_rx.c
index 325055ca41ab..0bab425f5dc9 100644
--- a/drivers/net/wireless/ath/ath11k/hal_rx.c
+++ b/drivers/net/wireless/ath/ath11k/hal_rx.c
@@ -29,8 +29,7 @@ static int ath11k_hal_reo_cmd_queue_stats(struct hal_tlv_hdr *tlv,
 		  FIELD_PREP(HAL_TLV_HDR_LEN, sizeof(*desc));
 
 	desc = (struct hal_reo_get_queue_stats *)tlv->value;
-	memset(&desc->queue_addr_lo, 0,
-	       (sizeof(*desc) - sizeof(struct hal_reo_cmd_hdr)));
+	memset_startat(desc, 0, queue_addr_lo);
 
 	desc->cmd.info0 &= ~HAL_REO_CMD_HDR_INFO0_STATUS_REQUIRED;
 	if (cmd->flag & HAL_REO_CMD_FLG_NEED_STATUS)
@@ -62,8 +61,7 @@ static int ath11k_hal_reo_cmd_flush_cache(struct ath11k_hal *hal, struct hal_tlv
 		  FIELD_PREP(HAL_TLV_HDR_LEN, sizeof(*desc));
 
 	desc = (struct hal_reo_flush_cache *)tlv->value;
-	memset(&desc->cache_addr_lo, 0,
-	       (sizeof(*desc) - sizeof(struct hal_reo_cmd_hdr)));
+	memset_startat(desc, 0, cache_addr_lo);
 
 	desc->cmd.info0 &= ~HAL_REO_CMD_HDR_INFO0_STATUS_REQUIRED;
 	if (cmd->flag & HAL_REO_CMD_FLG_NEED_STATUS)
@@ -101,8 +99,7 @@ static int ath11k_hal_reo_cmd_update_rx_queue(struct hal_tlv_hdr *tlv,
 		  FIELD_PREP(HAL_TLV_HDR_LEN, sizeof(*desc));
 
 	desc = (struct hal_reo_update_rx_queue *)tlv->value;
-	memset(&desc->queue_addr_lo, 0,
-	       (sizeof(*desc) - sizeof(struct hal_reo_cmd_hdr)));
+	memset_startat(desc, 0, queue_addr_lo);
 
 	desc->cmd.info0 &= ~HAL_REO_CMD_HDR_INFO0_STATUS_REQUIRED;
 	if (cmd->flag & HAL_REO_CMD_FLG_NEED_STATUS)
@@ -762,15 +759,17 @@ void ath11k_hal_reo_qdesc_setup(void *vaddr, int tid, u32 ba_window_size,
 	 * size changes and also send WMI message to FW to change the REO
 	 * queue descriptor in Rx peer entry as part of dp_rx_tid_update.
 	 */
-	memset(ext_desc, 0, 3 * sizeof(*ext_desc));
+	memset(ext_desc, 0, sizeof(*ext_desc));
 	ath11k_hal_reo_set_desc_hdr(&ext_desc->desc_hdr, HAL_DESC_REO_OWNED,
 				    HAL_DESC_REO_QUEUE_EXT_DESC,
 				    REO_QUEUE_DESC_MAGIC_DEBUG_PATTERN_1);
 	ext_desc++;
+	memset(ext_desc, 0, sizeof(*ext_desc));
 	ath11k_hal_reo_set_desc_hdr(&ext_desc->desc_hdr, HAL_DESC_REO_OWNED,
 				    HAL_DESC_REO_QUEUE_EXT_DESC,
 				    REO_QUEUE_DESC_MAGIC_DEBUG_PATTERN_2);
 	ext_desc++;
+	memset(ext_desc, 0, sizeof(*ext_desc));
 	ath11k_hal_reo_set_desc_hdr(&ext_desc->desc_hdr, HAL_DESC_REO_OWNED,
 				    HAL_DESC_REO_QUEUE_EXT_DESC,
 				    REO_QUEUE_DESC_MAGIC_DEBUG_PATTERN_3);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 46/63] iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (44 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 47/63] intel_th: msu: Use memset_startat() for clearing hw header Kees Cook
                   ` (16 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Potnuri Bharat Teja, Doug Ledford, Jason Gunthorpe,
	Raju Rangoju, David S. Miller, Jakub Kicinski, linux-rdma,
	netdev, Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct. Additionally, since everything
appears to perform a roundup (including allocation), just change the
size of the struct itself and add a build-time check to validate the
expected size.

Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Raju Rangoju <rajur@chelsio.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-rdma@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/infiniband/hw/cxgb4/cm.c            | 5 +++--
 drivers/net/ethernet/chelsio/cxgb4/t4_msg.h | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 291471d12197..6519ea8ebf23 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -2471,7 +2471,8 @@ static int accept_cr(struct c4iw_ep *ep, struct sk_buff *skb,
 	skb_get(skb);
 	rpl = cplhdr(skb);
 	if (!is_t4(adapter_type)) {
-		skb_trim(skb, roundup(sizeof(*rpl5), 16));
+		BUILD_BUG_ON(sizeof(*rpl5) != roundup(sizeof(*rpl5), 16));
+		skb_trim(skb, sizeof(*rpl5));
 		rpl5 = (void *)rpl;
 		INIT_TP_WR(rpl5, ep->hwtid);
 	} else {
@@ -2487,7 +2488,7 @@ static int accept_cr(struct c4iw_ep *ep, struct sk_buff *skb,
 		opt2 |= CONG_CNTRL_V(CONG_ALG_TAHOE);
 		opt2 |= T5_ISS_F;
 		rpl5 = (void *)rpl;
-		memset(&rpl5->iss, 0, roundup(sizeof(*rpl5)-sizeof(*rpl), 16));
+		memset_after(rpl5, 0, iss);
 		if (peer2peer)
 			isn += 4;
 		rpl5->iss = cpu_to_be32(isn);
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h b/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h
index fed5f93bf620..26433a62d7f0 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h
@@ -497,7 +497,7 @@ struct cpl_t5_pass_accept_rpl {
 	__be32 opt2;
 	__be64 opt0;
 	__be32 iss;
-	__be32 rsvd;
+	__be32 rsvd[3];
 };
 
 struct cpl_act_open_req {
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 47/63] intel_th: msu: Use memset_startat() for clearing hw header
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (45 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 46/63] iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-24  7:38   ` Alexander Shishkin
  2021-08-18  6:05 ` [PATCH v2 48/63] IB/mthca: Use memset_startat() for clearing mpt_entry Kees Cook
                   ` (15 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Alexander Shishkin, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/hwtracing/intel_th/msu.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index 432ade0842f6..70a07b4e9967 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -658,13 +658,11 @@ static void msc_buffer_clear_hw_header(struct msc *msc)
 
 	list_for_each_entry(win, &msc->win_list, entry) {
 		unsigned int blk;
-		size_t hw_sz = sizeof(struct msc_block_desc) -
-			offsetof(struct msc_block_desc, hw_tag);
 
 		for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
 			struct msc_block_desc *bdesc = sg_virt(sg);
 
-			memset(&bdesc->hw_tag, 0, hw_sz);
+			memset_startat(bdesc, 0, hw_tag);
 		}
 	}
 }
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 48/63] IB/mthca: Use memset_startat() for clearing mpt_entry
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (46 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 47/63] intel_th: msu: Use memset_startat() for clearing hw header Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct Kees Cook
                   ` (14 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Doug Ledford, Jason Gunthorpe, Max Gurtovoy,
	linux-rdma, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/infiniband/hw/mthca/mthca_mr.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c
index ce0e0867e488..1208e92ca3d3 100644
--- a/drivers/infiniband/hw/mthca/mthca_mr.c
+++ b/drivers/infiniband/hw/mthca/mthca_mr.c
@@ -469,8 +469,7 @@ int mthca_mr_alloc(struct mthca_dev *dev, u32 pd, int buffer_size_shift,
 	mpt_entry->start     = cpu_to_be64(iova);
 	mpt_entry->length    = cpu_to_be64(total_size);
 
-	memset(&mpt_entry->lkey, 0,
-	       sizeof *mpt_entry - offsetof(struct mthca_mpt_entry, lkey));
+	memset_startat(mpt_entry, 0, lkey);
 
 	if (mr->mtt)
 		mpt_entry->mtt_seg =
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (47 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 48/63] IB/mthca: Use memset_startat() for clearing mpt_entry Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:35   ` Nikolay Borisov
  2021-08-18  9:28   ` David Sterba
  2021-08-18  6:05 ` [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator Kees Cook
                   ` (13 subsequent siblings)
  62 siblings, 2 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Chris Mason, Josef Bacik, David Sterba, linux-btrfs,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 fs/btrfs/root-tree.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 702dc5441f03..12ceb14a1141 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -39,10 +39,8 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
 		need_reset = 1;
 	}
 	if (need_reset) {
-		memset(&item->generation_v2, 0,
-			sizeof(*item) - offsetof(struct btrfs_root_item,
-					generation_v2));
-
+		/* Clear all members from generation_v2 onwards. */
+		memset_startat(item, 0, generation_v2);
 		generate_random_guid(item->uuid);
 	}
 }
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (48 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18 13:33   ` Steven Rostedt
  2021-08-18  6:05 ` [PATCH v2 51/63] drbd: Use struct_group() to zero algs Kees Cook
                   ` (12 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Steven Rostedt, Ingo Molnar, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() to avoid confusing memset() about writing beyond
the target struct member.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 kernel/trace/trace.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 13587e771567..9ff8c31975cd 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6691,9 +6691,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 		cnt = PAGE_SIZE - 1;
 
 	/* reset all but tr, trace, and overruns */
-	memset(&iter->seq, 0,
-	       sizeof(struct trace_iterator) -
-	       offsetof(struct trace_iterator, seq));
+	memset_startat(iter, 0, seq);
 	cpumask_clear(iter->started);
 	trace_seq_init(&iter->seq);
 	iter->pos = -1;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 51/63] drbd: Use struct_group() to zero algs
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (49 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 52/63] cm4000_cs: Use struct_group() to zero struct cm4000_dev region Kees Cook
                   ` (11 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Philipp Reisner, Lars Ellenberg, Jens Axboe, drbd-dev,
	linux-block, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add a struct_group() for the algs so that memset() can correctly reason
about the size.

Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/block/drbd/drbd_main.c     | 3 ++-
 drivers/block/drbd/drbd_protocol.h | 6 ++++--
 drivers/block/drbd/drbd_receiver.c | 3 ++-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 55234a558e98..b824679cfcb2 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -729,7 +729,8 @@ int drbd_send_sync_param(struct drbd_peer_device *peer_device)
 	cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
 
 	/* initialize verify_alg and csums_alg */
-	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
+	BUILD_BUG_ON(sizeof(p->algs) != 2 * SHARED_SECRET_MAX);
+	memset(&p->algs, 0, sizeof(p->algs));
 
 	if (get_ldev(peer_device->device)) {
 		dc = rcu_dereference(peer_device->device->ldev->disk_conf);
diff --git a/drivers/block/drbd/drbd_protocol.h b/drivers/block/drbd/drbd_protocol.h
index dea59c92ecc1..a882b65ab5d2 100644
--- a/drivers/block/drbd/drbd_protocol.h
+++ b/drivers/block/drbd/drbd_protocol.h
@@ -283,8 +283,10 @@ struct p_rs_param_89 {
 
 struct p_rs_param_95 {
 	u32 resync_rate;
-	char verify_alg[SHARED_SECRET_MAX];
-	char csums_alg[SHARED_SECRET_MAX];
+	struct_group(algs,
+		char verify_alg[SHARED_SECRET_MAX];
+		char csums_alg[SHARED_SECRET_MAX];
+	);
 	u32 c_plan_ahead;
 	u32 c_delay_target;
 	u32 c_fill_target;
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 1f740e42e457..6df2539e215b 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3921,7 +3921,8 @@ static int receive_SyncParam(struct drbd_connection *connection, struct packet_i
 
 	/* initialize verify_alg and csums_alg */
 	p = pi->data;
-	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
+	BUILD_BUG_ON(sizeof(p->algs) != 2 * SHARED_SECRET_MAX);
+	memset(&p->algs, 0, sizeof(p->algs));
 
 	err = drbd_recv_all(peer_device->connection, p, header_size);
 	if (err)
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 52/63] cm4000_cs: Use struct_group() to zero struct cm4000_dev region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (50 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 51/63] drbd: Use struct_group() to zero algs Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache Kees Cook
                   ` (10 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Harald Welte, Arnd Bergmann, Greg Kroah-Hartman,
	Gustavo A. R. Silva, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark region of struct cm4000_dev that should be
initialized to zero.

Cc: Harald Welte <laforge@gnumonks.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/lkml/YQDvxAofJlI1JoGZ@kroah.com
---
 drivers/char/pcmcia/cm4000_cs.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c
index 8f1bce0b4fe5..2f43e7088e16 100644
--- a/drivers/char/pcmcia/cm4000_cs.c
+++ b/drivers/char/pcmcia/cm4000_cs.c
@@ -116,8 +116,9 @@ struct cm4000_dev {
 	wait_queue_head_t atrq;		/* wait for ATR valid */
 	wait_queue_head_t readq;	/* used by write to wake blk.read */
 
-	/* warning: do not move this fields.
+	/* warning: do not move this struct group.
 	 * initialising to zero depends on it - see ZERO_DEV below.  */
+	struct_group(init,
 	unsigned char atr_csum;
 	unsigned char atr_len_retry;
 	unsigned short atr_len;
@@ -140,12 +141,10 @@ struct cm4000_dev {
 
 	struct timer_list timer;	/* used to keep monitor running */
 	int monitor_running;
+	);
 };
 
-#define	ZERO_DEV(dev)  						\
-	memset(&dev->atr_csum,0,				\
-		sizeof(struct cm4000_dev) - 			\
-		offsetof(struct cm4000_dev, atr_csum))
+#define	ZERO_DEV(dev)	memset(&dev->init, 0, sizeof(dev->init))
 
 static struct pcmcia_device *dev_table[CM4000_MAX_DEV];
 static struct class *cmm_class;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (51 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 52/63] cm4000_cs: Use struct_group() to zero struct cm4000_dev region Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18 15:11   ` Sean Christopherson
  2021-08-18  6:05 ` [PATCH v2 54/63] dm integrity: Use struct_group() to zero struct journal_sector Kees Cook
                   ` (9 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Paolo Bonzini, Sean Christopherson, Vitaly Kuznetsov,
	Wanpeng Li, Jim Mattson, Joerg Roedel, Thomas Gleixner,
	Ingo Molnar, Borislav Petkov, x86, H. Peter Anvin, kvm,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark region of struct x86_emulate_ctxt that should
be initialized to zero.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/kvm/emulate.c     |  3 +--
 arch/x86/kvm/kvm_emulate.h | 19 +++++++++++--------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2837110e66ed..2608a047e769 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5377,8 +5377,7 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
 
 void init_decode_cache(struct x86_emulate_ctxt *ctxt)
 {
-	memset(&ctxt->rip_relative, 0,
-	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
+	memset(&ctxt->decode_cache, 0, sizeof(ctxt->decode_cache));
 
 	ctxt->io_read.pos = 0;
 	ctxt->io_read.end = 0;
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 68b420289d7e..9b8afcb8ad39 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -341,14 +341,17 @@ struct x86_emulate_ctxt {
 	 * the rest are initialized unconditionally in x86_decode_insn
 	 * or elsewhere
 	 */
-	bool rip_relative;
-	u8 rex_prefix;
-	u8 lock_prefix;
-	u8 rep_prefix;
-	/* bitmaps of registers in _regs[] that can be read */
-	u32 regs_valid;
-	/* bitmaps of registers in _regs[] that have been written */
-	u32 regs_dirty;
+	struct_group(decode_cache,
+		bool rip_relative;
+		u8 rex_prefix;
+		u8 lock_prefix;
+		u8 rep_prefix;
+		/* bitmaps of registers in _regs[] that can be read */
+		u32 regs_valid;
+		/* bitmaps of registers in _regs[] that have been written */
+		u32 regs_dirty;
+	);
+
 	/* modrm */
 	u8 modrm;
 	u8 modrm_mod;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 54/63] dm integrity: Use struct_group() to zero struct journal_sector
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (52 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event Kees Cook
                   ` (8 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Alasdair Kergon, Mike Snitzer, dm-devel,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark region of struct journal_sector that should be
initialized to zero.

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/md/dm-integrity.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 40f8116c8e44..59deea0dd305 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -119,8 +119,10 @@ struct journal_entry {
 #define JOURNAL_MAC_SIZE		(JOURNAL_MAC_PER_SECTOR * JOURNAL_BLOCK_SECTORS)
 
 struct journal_sector {
-	__u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
-	__u8 mac[JOURNAL_MAC_PER_SECTOR];
+	struct_group(sectors,
+		__u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
+		__u8 mac[JOURNAL_MAC_PER_SECTOR];
+	);
 	commit_id_t commit_id;
 };
 
@@ -2856,7 +2858,8 @@ static void init_journal(struct dm_integrity_c *ic, unsigned start_section,
 		wraparound_section(ic, &i);
 		for (j = 0; j < ic->journal_section_sectors; j++) {
 			struct journal_sector *js = access_journal(ic, i, j);
-			memset(&js->entries, 0, JOURNAL_SECTOR_DATA);
+			BUILD_BUG_ON(sizeof(js->sectors) != JOURNAL_SECTOR_DATA);
+			memset(&js->sectors, 0, sizeof(js->sectors));
 			js->commit_id = dm_integrity_commit_id(ic, i, j, commit_seq);
 		}
 		for (j = 0; j < ic->journal_section_entries; j++) {
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (53 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 54/63] dm integrity: Use struct_group() to zero struct journal_sector Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-20 13:02   ` Jiri Kosina
  2021-08-18  6:05 ` [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr Kees Cook
                   ` (7 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Stefan Achatz, Jiri Kosina, Benjamin Tissoires,
	linux-input, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark region of struct kone_mouse_event that should
be initialized to zero.

Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/hid/hid-roccat-kone.c |  2 +-
 drivers/hid/hid-roccat-kone.h | 12 +++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/hid/hid-roccat-kone.c b/drivers/hid/hid-roccat-kone.c
index 1ca64481145e..ea17abc7ad52 100644
--- a/drivers/hid/hid-roccat-kone.c
+++ b/drivers/hid/hid-roccat-kone.c
@@ -857,7 +857,7 @@ static int kone_raw_event(struct hid_device *hdev, struct hid_report *report,
 		memcpy(&kone->last_mouse_event, event,
 				sizeof(struct kone_mouse_event));
 	else
-		memset(&event->tilt, 0, 5);
+		memset(&event->wipe, 0, sizeof(event->wipe));
 
 	kone_keep_values_up_to_date(kone, event);
 
diff --git a/drivers/hid/hid-roccat-kone.h b/drivers/hid/hid-roccat-kone.h
index 4a1a9cb76b08..65c800e3addc 100644
--- a/drivers/hid/hid-roccat-kone.h
+++ b/drivers/hid/hid-roccat-kone.h
@@ -152,11 +152,13 @@ struct kone_mouse_event {
 	uint16_t x;
 	uint16_t y;
 	uint8_t wheel; /* up = 1, down = -1 */
-	uint8_t tilt; /* right = 1, left = -1 */
-	uint8_t unknown;
-	uint8_t event;
-	uint8_t value; /* press = 0, release = 1 */
-	uint8_t macro_key; /* 0 to 8 */
+	struct_group(wipe,
+		uint8_t tilt; /* right = 1, left = -1 */
+		uint8_t unknown;
+		uint8_t event;
+		uint8_t value; /* press = 0, release = 1 */
+		uint8_t macro_key; /* 0 to 8 */
+	);
 } __attribute__ ((__packed__));
 
 enum kone_mouse_events {
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (54 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-19 12:27   ` Jason Gunthorpe
  2021-08-18  6:05 ` [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs Kees Cook
                   ` (6 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Leon Romanovsky, Doug Ledford, Jason Gunthorpe,
	linux-rdma, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark region of struct mlx5_ib_mr that should be
initialized to zero.

Cc: Leon Romanovsky <leon@kernel.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index bf20a388eabe..f63bf204a7a1 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -644,6 +644,7 @@ struct mlx5_ib_mr {
 	struct ib_umem *umem;
 
 	/* This is zero'd when the MR is allocated */
+	struct_group(cleared,
 	union {
 		/* Used only while the MR is in the cache */
 		struct {
@@ -691,12 +692,13 @@ struct mlx5_ib_mr {
 			bool is_odp_implicit;
 		};
 	};
+	);
 };
 
 /* Zero the fields in the mr that are variant depending on usage */
 static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
 {
-	memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
+	memset(&mr->cleared, 0, sizeof(mr->cleared));
 }
 
 static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (55 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-20  7:49   ` Michael Ellerman
  2021-08-18  6:05 ` [PATCH v2 58/63] ethtool: stats: Use struct_group() to clear all stats at once Kees Cook
                   ` (5 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Michael Ellerman, Benjamin Herrenschmidt,
	Paul Mackerras, Christophe Leroy, Sudeep Holla, linuxppc-dev,
	kernel test robot, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add a struct_group() for the spe registers so that memset() can correctly reason
about the size:

   In function 'fortify_memset_chk',
       inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
>> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
     195 |    __write_overflow_field();
         |    ^~~~~~~~~~~~~~~~~~~~~~~~

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/powerpc/include/asm/processor.h | 6 ++++--
 arch/powerpc/kernel/signal_32.c      | 6 +++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index f348e564f7dd..05dc567cb9a8 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -191,8 +191,10 @@ struct thread_struct {
 	int		used_vsr;	/* set if process has used VSX */
 #endif /* CONFIG_VSX */
 #ifdef CONFIG_SPE
-	unsigned long	evr[32];	/* upper 32-bits of SPE regs */
-	u64		acc;		/* Accumulator */
+	struct_group(spe,
+		unsigned long	evr[32];	/* upper 32-bits of SPE regs */
+		u64		acc;		/* Accumulator */
+	);
 	unsigned long	spefscr;	/* SPE & eFP status */
 	unsigned long	spefscr_last;	/* SPEFSCR value on last prctl
 					   call or trap return */
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 0608581967f0..77b86caf5c51 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs,
 	regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
 	if (msr & MSR_SPE) {
 		/* restore spe registers from the stack */
-		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
-				      ELF_NEVRREG * sizeof(u32), failed);
+		unsafe_copy_from_user(&current->thread.spe, &sr->mc_vregs,
+				      sizeof(current->thread.spe), failed);
 		current->thread.used_spe = true;
 	} else if (current->thread.used_spe)
-		memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
+		memset(&current->thread.spe, 0, sizeof(current->thread.spe));
 
 	/* Always get SPEFSCR back */
 	unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 58/63] ethtool: stats: Use struct_group() to clear all stats at once
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (56 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions Kees Cook
                   ` (4 subsequent siblings)
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, David S. Miller, Jakub Kicinski, Ido Schimmel, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark region of struct stats_reply_data that should
be initialized, which can now be done in a single memset() call.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Ido Schimmel <idosch@nvidia.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/ethtool/stats.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/net/ethtool/stats.c b/net/ethtool/stats.c
index ec07f5765e03..a20e0a24ff61 100644
--- a/net/ethtool/stats.c
+++ b/net/ethtool/stats.c
@@ -14,10 +14,12 @@ struct stats_req_info {
 
 struct stats_reply_data {
 	struct ethnl_reply_data		base;
-	struct ethtool_eth_phy_stats	phy_stats;
-	struct ethtool_eth_mac_stats	mac_stats;
-	struct ethtool_eth_ctrl_stats	ctrl_stats;
-	struct ethtool_rmon_stats	rmon_stats;
+	struct_group(stats,
+		struct ethtool_eth_phy_stats	phy_stats;
+		struct ethtool_eth_mac_stats	mac_stats;
+		struct ethtool_eth_ctrl_stats	ctrl_stats;
+		struct ethtool_rmon_stats	rmon_stats;
+	);
 	const struct ethtool_rmon_hist_range	*rmon_ranges;
 };
 
@@ -117,10 +119,7 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 	/* Mark all stats as unset (see ETHTOOL_STAT_NOT_SET) to prevent them
 	 * from being reported to user space in case driver did not set them.
 	 */
-	memset(&data->phy_stats, 0xff, sizeof(data->phy_stats));
-	memset(&data->mac_stats, 0xff, sizeof(data->mac_stats));
-	memset(&data->ctrl_stats, 0xff, sizeof(data->ctrl_stats));
-	memset(&data->rmon_stats, 0xff, sizeof(data->rmon_stats));
+	memset(&data->stats, 0xff, sizeof(data->stats));
 
 	if (test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask) &&
 	    dev->ethtool_ops->get_eth_phy_stats)
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (57 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 58/63] ethtool: stats: Use struct_group() to clear all stats at once Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:26   ` Marc Kleine-Budde
  2021-08-18  6:05 ` [PATCH v2 60/63] net/af_iucv: Use struct_group() to zero struct iucv_sock region Kees Cook
                   ` (3 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Wolfgang Grandegger, Marc Kleine-Budde,
	David S. Miller, Jakub Kicinski, linux-can, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark both regions of struct flexcan_regs that get
initialized to zero. Avoid the future warnings:

In function 'fortify_memset_chk',
    inlined from 'memset_io' at ./include/asm-generic/io.h:1169:2,
    inlined from 'flexcan_ram_init' at drivers/net/can/flexcan.c:1403:2:
./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
  199 |    __write_overflow_field(p_size_field, size);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'fortify_memset_chk',
    inlined from 'memset_io' at ./include/asm-generic/io.h:1169:2,
    inlined from 'flexcan_ram_init' at drivers/net/can/flexcan.c:1408:3:
./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
  199 |    __write_overflow_field(p_size_field, size);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-can@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/can/flexcan.c | 68 +++++++++++++++++++--------------------
 1 file changed, 34 insertions(+), 34 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 7734229aa078..12b60ad95b02 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -290,31 +290,33 @@ struct flexcan_regs {
 	u32 dbg1;		/* 0x58 */
 	u32 dbg2;		/* 0x5c */
 	u32 _reserved3[8];	/* 0x60 */
-	u8 mb[2][512];		/* 0x80 - Not affected by Soft Reset */
-	/* FIFO-mode:
-	 *			MB
-	 * 0x080...0x08f	0	RX message buffer
-	 * 0x090...0x0df	1-5	reserved
-	 * 0x0e0...0x0ff	6-7	8 entry ID table
-	 *				(mx25, mx28, mx35, mx53)
-	 * 0x0e0...0x2df	6-7..37	8..128 entry ID table
-	 *				size conf'ed via ctrl2::RFFN
-	 *				(mx6, vf610)
-	 */
-	u32 _reserved4[256];	/* 0x480 */
-	u32 rximr[64];		/* 0x880 - Not affected by Soft Reset */
-	u32 _reserved5[24];	/* 0x980 */
-	u32 gfwr_mx6;		/* 0x9e0 - MX6 */
-	u32 _reserved6[39];	/* 0x9e4 */
-	u32 _rxfir[6];		/* 0xa80 */
-	u32 _reserved8[2];	/* 0xa98 */
-	u32 _rxmgmask;		/* 0xaa0 */
-	u32 _rxfgmask;		/* 0xaa4 */
-	u32 _rx14mask;		/* 0xaa8 */
-	u32 _rx15mask;		/* 0xaac */
-	u32 tx_smb[4];		/* 0xab0 */
-	u32 rx_smb0[4];		/* 0xac0 */
-	u32 rx_smb1[4];		/* 0xad0 */
+	struct_group(init,
+		u8 mb[2][512];		/* 0x80 - Not affected by Soft Reset */
+		/* FIFO-mode:
+		 *			MB
+		 * 0x080...0x08f	0	RX message buffer
+		 * 0x090...0x0df	1-5	reserved
+		 * 0x0e0...0x0ff	6-7	8 entry ID table
+		 *				(mx25, mx28, mx35, mx53)
+		 * 0x0e0...0x2df	6-7..37	8..128 entry ID table
+		 *				size conf'ed via ctrl2::RFFN
+		 *				(mx6, vf610)
+		 */
+		u32 _reserved4[256];	/* 0x480 */
+		u32 rximr[64];		/* 0x880 - Not affected by Soft Reset */
+		u32 _reserved5[24];	/* 0x980 */
+		u32 gfwr_mx6;		/* 0x9e0 - MX6 */
+		u32 _reserved6[39];	/* 0x9e4 */
+		u32 _rxfir[6];		/* 0xa80 */
+		u32 _reserved8[2];	/* 0xa98 */
+		u32 _rxmgmask;		/* 0xaa0 */
+		u32 _rxfgmask;		/* 0xaa4 */
+		u32 _rx14mask;		/* 0xaa8 */
+		u32 _rx15mask;		/* 0xaac */
+		u32 tx_smb[4];		/* 0xab0 */
+		u32 rx_smb0[4];		/* 0xac0 */
+		u32 rx_smb1[4];		/* 0xad0 */
+	);
 	u32 mecr;		/* 0xae0 */
 	u32 erriar;		/* 0xae4 */
 	u32 erridpr;		/* 0xae8 */
@@ -328,9 +330,11 @@ struct flexcan_regs {
 	u32 fdcbt;		/* 0xc04 - Not affected by Soft Reset */
 	u32 fdcrc;		/* 0xc08 */
 	u32 _reserved9[199];	/* 0xc0c */
-	u32 tx_smb_fd[18];	/* 0xf28 */
-	u32 rx_smb0_fd[18];	/* 0xf70 */
-	u32 rx_smb1_fd[18];	/* 0xfb8 */
+	struct_group(init_fd,
+		u32 tx_smb_fd[18];	/* 0xf28 */
+		u32 rx_smb0_fd[18];	/* 0xf70 */
+		u32 rx_smb1_fd[18];	/* 0xfb8 */
+	);
 };
 
 static_assert(sizeof(struct flexcan_regs) ==  0x4 * 18 + 0xfb8);
@@ -1400,14 +1404,10 @@ static void flexcan_ram_init(struct net_device *dev)
 	reg_ctrl2 |= FLEXCAN_CTRL2_WRMFRZ;
 	priv->write(reg_ctrl2, &regs->ctrl2);
 
-	memset_io(&regs->mb[0][0], 0,
-		  offsetof(struct flexcan_regs, rx_smb1[3]) -
-		  offsetof(struct flexcan_regs, mb[0][0]) + 0x4);
+	memset_io(&regs->init, 0, sizeof(regs->init));
 
 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
-		memset_io(&regs->tx_smb_fd[0], 0,
-			  offsetof(struct flexcan_regs, rx_smb1_fd[17]) -
-			  offsetof(struct flexcan_regs, tx_smb_fd[0]) + 0x4);
+		memset_io(&regs->init_fd, 0, sizeof(regs->init_fd));
 
 	reg_ctrl2 &= ~FLEXCAN_CTRL2_WRMFRZ;
 	priv->write(reg_ctrl2, &regs->ctrl2);
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 60/63] net/af_iucv: Use struct_group() to zero struct iucv_sock region
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (58 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-09-09  6:14   ` Karsten Graul
  2021-08-18  6:05 ` [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow Kees Cook
                   ` (2 subsequent siblings)
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Julian Wiedmann, Karsten Graul, David S. Miller,
	Jakub Kicinski, linux-s390, netdev, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark the region of struct iucv_sock that gets
initialized to zero. Avoid the future warning:

In function 'fortify_memset_chk',
    inlined from 'iucv_sock_alloc' at net/iucv/af_iucv.c:476:2:
./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
  199 |    __write_overflow_field(p_size_field, size);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Julian Wiedmann <jwi@linux.ibm.com>
Cc: Karsten Graul <kgraul@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-s390@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/net/iucv/af_iucv.h | 10 ++++++----
 net/iucv/af_iucv.c         |  2 +-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h
index ff06246dbbb9..df85d19fbf84 100644
--- a/include/net/iucv/af_iucv.h
+++ b/include/net/iucv/af_iucv.h
@@ -112,10 +112,12 @@ enum iucv_tx_notify {
 
 struct iucv_sock {
 	struct sock		sk;
-	char			src_user_id[8];
-	char			src_name[8];
-	char			dst_user_id[8];
-	char			dst_name[8];
+	struct_group(init,
+		char		src_user_id[8];
+		char		src_name[8];
+		char		dst_user_id[8];
+		char		dst_name[8];
+	);
 	struct list_head	accept_q;
 	spinlock_t		accept_q_lock;
 	struct sock		*parent;
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 18316ee3c692..9446e2771d31 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -473,7 +473,7 @@ static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio,
 	atomic_set(&iucv->msg_recv, 0);
 	iucv->path = NULL;
 	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
-	memset(&iucv->src_user_id , 0, 32);
+	memset(&iucv->init, 0, sizeof(iucv->init));
 	if (pr_iucv)
 		iucv->transport = AF_IUCV_TRANS_IUCV;
 	else
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (59 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 60/63] net/af_iucv: Use struct_group() to zero struct iucv_sock region Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:42   ` Christophe Leroy
  2021-08-18  6:05 ` [PATCH v2 62/63] fortify: Detect struct member overflows in memset() at compile-time Kees Cook
  2021-08-18  6:05 ` [PATCH v2 63/63] fortify: Work around Clang inlining bugs Kees Cook
  62 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Benjamin Herrenschmidt, Qinglang Miao,
	Gustavo A. R. Silva, Hulk Robot, Wang Wensheng, linuxppc-dev,
	Michael Ellerman, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Instead of writing across a field boundary with memset(), move the call
to just the array, and an explicit zeroing of the prior field.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Qinglang Miao <miaoqinglang@huawei.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Wang Wensheng <wangwensheng4@huawei.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/lkml/87czqsnmw9.fsf@mpe.ellerman.id.au
---
 drivers/macintosh/smu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 94fb63a7b357..59ce431da7ef 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -848,7 +848,8 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 	cmd->read = cmd->info.devaddr & 0x01;
 	switch(cmd->info.type) {
 	case SMU_I2C_TRANSFER_SIMPLE:
-		memset(&cmd->info.sublen, 0, 4);
+		cmd->info.sublen = 0;
+		memset(&cmd->info.subaddr, 0, 3);
 		break;
 	case SMU_I2C_TRANSFER_COMBINED:
 		cmd->info.devaddr &= 0xfe;
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 62/63] fortify: Detect struct member overflows in memset() at compile-time
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (60 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  2021-08-18  6:05 ` [PATCH v2 63/63] fortify: Work around Clang inlining bugs Kees Cook
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

As done for memcpy(), also update memset() to use the same tightened
compile-time bounds checking under CONFIG_FORTIFY_SOURCE.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h                | 54 ++++++++++++++++---
 .../write_overflow_field-memset.c             |  5 ++
 2 files changed, 51 insertions(+), 8 deletions(-)
 create mode 100644 lib/test_fortify/write_overflow_field-memset.c

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 0120d463ba33..7de4673dfe2c 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -198,17 +198,56 @@ __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
 	return p;
 }
 
-__FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
+__FORTIFY_INLINE void fortify_memset_chk(__kernel_size_t size,
+					 const size_t p_size,
+					 const size_t p_size_field)
 {
-	size_t p_size = __builtin_object_size(p, 0);
+	if (__builtin_constant_p(size)) {
+		/*
+		 * Length argument is a constant expression, so we
+		 * can perform compile-time bounds checking where
+		 * buffer sizes are known.
+		 */
 
-	if (__builtin_constant_p(size) && p_size < size)
-		__write_overflow();
-	if (p_size < size)
-		fortify_panic(__func__);
-	return __underlying_memset(p, c, size);
+		/* Error when size is larger than enclosing struct. */
+		if (p_size > p_size_field && p_size < size)
+			__write_overflow();
+
+		/* Warn when write size is larger than dest field. */
+		if (p_size_field < size)
+			__write_overflow_field(p_size_field, size);
+	}
+	/*
+	 * At this point, length argument may not be a constant expression,
+	 * so run-time bounds checking can be done where buffer sizes are
+	 * known. (This is not an "else" because the above checks may only
+	 * be compile-time warnings, and we want to still warn for run-time
+	 * overflows.)
+	 */
+
+	/*
+	 * Always stop accesses beyond the struct that contains the
+	 * field, when the buffer's remaining size is known.
+	 * (The -1 test is to optimize away checks where the buffer
+	 * lengths are unknown.)
+	 */
+	if (p_size != (size_t)(-1) && p_size < size)
+		fortify_panic("memset");
 }
 
+#define __fortify_memset_chk(p, c, size, p_size, p_size_field) ({	\
+	size_t __fortify_size = (size_t)(size);				\
+	fortify_memset_chk(__fortify_size, p_size, p_size_field),	\
+	__underlying_memset(p, c, __fortify_size);			\
+})
+
+/*
+ * __builtin_object_size() must be captured here to avoid evaluating argument
+ * side-effects further into the macro layers.
+ */
+#define memset(p, c, s) __fortify_memset_chk(p, c, s,			\
+		__builtin_object_size(p, 0), __builtin_object_size(p, 1))
+
 /*
  * To make sure the compiler can enforce protection against buffer overflows,
  * memcpy(), memmove(), and memset() must not be used beyond individual
@@ -399,7 +438,6 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 /* Don't use these outside the FORITFY_SOURCE implementation */
 #undef __underlying_memchr
 #undef __underlying_memcmp
-#undef __underlying_memset
 #undef __underlying_strcat
 #undef __underlying_strcpy
 #undef __underlying_strlen
diff --git a/lib/test_fortify/write_overflow_field-memset.c b/lib/test_fortify/write_overflow_field-memset.c
new file mode 100644
index 000000000000..2331da26909e
--- /dev/null
+++ b/lib/test_fortify/write_overflow_field-memset.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define TEST	\
+	memset(instance.buf, 0x42, sizeof(instance.buf) + 1)
+
+#include "test_fortify.h"
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* [PATCH v2 63/63] fortify: Work around Clang inlining bugs
  2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
                   ` (61 preceding siblings ...)
  2021-08-18  6:05 ` [PATCH v2 62/63] fortify: Detect struct member overflows in memset() at compile-time Kees Cook
@ 2021-08-18  6:05 ` Kees Cook
  62 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  6:05 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

To enable FORTIFY_SOURCE support for Clang, the kernel must work around
a pair of bugs, related to Clang's inlining.

Change all the fortified APIs into macros with different inline names to
bypass Clang's broken inline-of-a-builtin detection:
https://bugs.llvm.org/show_bug.cgi?id=50322

Lift all misbehaving __builtin_object_size() calls into the macros to
bypass Clang's broken __builtin_object_size() arguments-of-an-inline
visibility:
https://github.com/ClangBuiltLinux/linux/issues/1401

Thankfully, due to how the inlining already behaves in GCC, this change
has no effect on GCC builds, but allows Clang to finally gain full
FORTIFY coverage.

However, because of a third bug which had no work-arounds, FORTIFY_SOURCE
will only work with Clang version 13 and later. Update the Kconfig to
reflect the new requirements.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/fortify-string.h | 55 +++++++++++++++++++++-------------
 security/Kconfig               |  2 +-
 2 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 7de4673dfe2c..e62d3633a329 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -48,10 +48,10 @@ extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size)
 #define __underlying_strncpy	__builtin_strncpy
 #endif
 
-__FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
+#define strncpy(p, q, s) __fortify_strncpy(p, q, s, __builtin_object_size(p, 1))
+__FORTIFY_INLINE char *__fortify_strncpy(char *p, const char *q,
+					 __kernel_size_t size, size_t p_size)
 {
-	size_t p_size = __builtin_object_size(p, 1);
-
 	if (__builtin_constant_p(size) && p_size < size)
 		__write_overflow();
 	if (p_size < size)
@@ -71,9 +71,10 @@ __FORTIFY_INLINE char *strcat(char *p, const char *q)
 }
 
 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
-__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
+#define strnlen(p, s) __fortify_strnlen(p, s, __builtin_object_size(p, 1))
+__FORTIFY_INLINE __kernel_size_t __fortify_strnlen(const char *p, size_t maxlen,
+						   size_t p_size)
 {
-	size_t p_size = __builtin_object_size(p, 1);
 	size_t p_len = __compiletime_strlen(p);
 	size_t ret;
 
@@ -108,10 +109,14 @@ __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 
 /* defined after fortified strlen to reuse it */
 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
-__FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
+#define strlcpy(p, q, s) __fortify_strlcpy(p, q, s,			\
+					   __builtin_object_size(p, 1),	\
+					   __builtin_object_size(q, 1))
+__FORTIFY_INLINE size_t __fortify_strlcpy(char *p, const char *q,
+					  size_t size,
+					  const size_t p_size,
+					  const size_t q_size)
 {
-	size_t p_size = __builtin_object_size(p, 1);
-	size_t q_size = __builtin_object_size(q, 1);
 	size_t q_len;	/* Full count of source string length. */
 	size_t len;	/* Count of characters going into destination. */
 
@@ -135,12 +140,15 @@ __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
 
 /* defined after fortified strnlen to reuse it */
 extern ssize_t __real_strscpy(char *, const char *, size_t) __RENAME(strscpy);
-__FORTIFY_INLINE ssize_t strscpy(char *p, const char *q, size_t size)
+#define strscpy(p, q, s) __fortify_strscpy(p, q, s,			\
+					   __builtin_object_size(p, 1),	\
+					   __builtin_object_size(q, 1))
+__FORTIFY_INLINE ssize_t __fortify_strscpy(char *p, const char *q,
+					   size_t size,
+					   const size_t p_size,
+					   const size_t q_size)
 {
 	size_t len;
-	/* Use string size rather than possible enclosing struct size. */
-	size_t p_size = __builtin_object_size(p, 1);
-	size_t q_size = __builtin_object_size(q, 1);
 
 	/* If we cannot get size of p and q default to call strscpy. */
 	if (p_size == (size_t) -1 && q_size == (size_t) -1)
@@ -181,11 +189,13 @@ __FORTIFY_INLINE ssize_t strscpy(char *p, const char *q, size_t size)
 }
 
 /* defined after fortified strlen and strnlen to reuse them */
-__FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
+#define strncat(p, q, count)	__fortify_strncat(p, q, count, \
+						  __builtin_object_size(p, 1), \
+						  __builtin_object_size(q, 1))
+__FORTIFY_INLINE char *__fortify_strncat(char *p, const char *q, size_t count,
+					 size_t p_size, size_t q_size)
 {
 	size_t p_len, copy_len;
-	size_t p_size = __builtin_object_size(p, 1);
-	size_t q_size = __builtin_object_size(q, 1);
 
 	if (p_size == (size_t)-1 && q_size == (size_t)-1)
 		return __underlying_strncat(p, q, count);
@@ -352,7 +362,8 @@ __FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size,
 		memmove)
 
 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
-__FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
+#define memscan(p, c, s) __fortify_memscan(p, c, s)
+__FORTIFY_INLINE void *__fortify_memscan(void *p, int c, __kernel_size_t size)
 {
 	size_t p_size = __builtin_object_size(p, 0);
 
@@ -363,7 +374,8 @@ __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
 	return __real_memscan(p, c, size);
 }
 
-__FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
+#define memcmp(p, q, s) __fortify_memcmp(p, q, s)
+__FORTIFY_INLINE int __fortify_memcmp(const void *p, const void *q, __kernel_size_t size)
 {
 	size_t p_size = __builtin_object_size(p, 0);
 	size_t q_size = __builtin_object_size(q, 0);
@@ -379,7 +391,8 @@ __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
 	return __underlying_memcmp(p, q, size);
 }
 
-__FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
+#define memchr(p, c, s) __fortify_memchr(p, c, s)
+__FORTIFY_INLINE void *__fortify_memchr(const void *p, int c, __kernel_size_t size)
 {
 	size_t p_size = __builtin_object_size(p, 0);
 
@@ -391,7 +404,8 @@ __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
 }
 
 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
-__FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
+#define memchr_inv(p, c, s) __fortify_memchr_inv(p, c, s)
+__FORTIFY_INLINE void *__fortify_memchr_inv(const void *p, int c, size_t size)
 {
 	size_t p_size = __builtin_object_size(p, 0);
 
@@ -415,7 +429,8 @@ __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
 }
 
 /* Defined after fortified strlen to reuse it. */
-__FORTIFY_INLINE char *strcpy(char *p, const char *q)
+#define strcpy(p, q) __fortify_strcpy(p, q)
+__FORTIFY_INLINE char *__fortify_strcpy(char *p, const char *q)
 {
 	size_t p_size = __builtin_object_size(p, 1);
 	size_t q_size = __builtin_object_size(q, 1);
diff --git a/security/Kconfig b/security/Kconfig
index fe6c0395fa02..530a15566b1d 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -193,7 +193,7 @@ config FORTIFY_SOURCE
 	depends on ARCH_HAS_FORTIFY_SOURCE
 	# https://bugs.llvm.org/show_bug.cgi?id=50322
 	# https://bugs.llvm.org/show_bug.cgi?id=41459
-	depends on !CC_IS_CLANG
+	depends on !CC_IS_CLANG || CLANG_VERSION >= 130000
 	help
 	  Detect overflows of buffers in common string and memory functions
 	  where the compiler can determine and validate the buffer sizes.
-- 
2.30.2


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions
  2021-08-18  6:05 ` [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions Kees Cook
@ 2021-08-18  6:26   ` Marc Kleine-Budde
  0 siblings, 0 replies; 116+ messages in thread
From: Marc Kleine-Budde @ 2021-08-18  6:26 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Wolfgang Grandegger, David S. Miller,
	Jakub Kicinski, linux-can, netdev, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

[-- Attachment #1: Type: text/plain, Size: 2620 bytes --]

On 17.08.2021 23:05:29, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Add struct_group() to mark both regions of struct flexcan_regs that get
> initialized to zero. Avoid the future warnings:
> 
> In function 'fortify_memset_chk',
>     inlined from 'memset_io' at ./include/asm-generic/io.h:1169:2,
>     inlined from 'flexcan_ram_init' at drivers/net/can/flexcan.c:1403:2:
> ./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
>   199 |    __write_overflow_field(p_size_field, size);
>       |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> In function 'fortify_memset_chk',
>     inlined from 'memset_io' at ./include/asm-generic/io.h:1169:2,
>     inlined from 'flexcan_ram_init' at drivers/net/can/flexcan.c:1408:3:
> ./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
>   199 |    __write_overflow_field(p_size_field, size);
>       |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Cc: Wolfgang Grandegger <wg@grandegger.com>
> Cc: Marc Kleine-Budde <mkl@pengutronix.de>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: linux-can@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

> -	memset_io(&regs->mb[0][0], 0,
> -		  offsetof(struct flexcan_regs, rx_smb1[3]) -
> -		  offsetof(struct flexcan_regs, mb[0][0]) + 0x4);
> +	memset_io(&regs->init, 0, sizeof(regs->init));

This even makes the code more readable! \o/

>  	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
> -		memset_io(&regs->tx_smb_fd[0], 0,
> -			  offsetof(struct flexcan_regs, rx_smb1_fd[17]) -
> -			  offsetof(struct flexcan_regs, tx_smb_fd[0]) + 0x4);
> +		memset_io(&regs->init_fd, 0, sizeof(regs->init_fd));
>  
>  	reg_ctrl2 &= ~FLEXCAN_CTRL2_WRMFRZ;
>  	priv->write(reg_ctrl2, &regs->ctrl2);

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct
  2021-08-18  6:05 ` [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct Kees Cook
@ 2021-08-18  6:35   ` Nikolay Borisov
  2021-08-18  9:28   ` David Sterba
  1 sibling, 0 replies; 116+ messages in thread
From: Nikolay Borisov @ 2021-08-18  6:35 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: Chris Mason, Josef Bacik, David Sterba, linux-btrfs,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening



On 18.08.21 г. 9:05, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Use memset_startat() so memset() doesn't get confused about writing
> beyond the destination member that is intended to be the starting point
> of zeroing through the end of the struct.
> 
> Cc: Chris Mason <clm@fb.com>
> Cc: Josef Bacik <josef@toxicpanda.com>
> Cc: David Sterba <dsterba@suse.com>
> Cc: linux-btrfs@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow
  2021-08-18  6:05 ` [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow Kees Cook
@ 2021-08-18  6:42   ` Christophe Leroy
  2021-08-18 22:30     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Christophe Leroy @ 2021-08-18  6:42 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: Rasmus Villemoes, Greg Kroah-Hartman, Wang Wensheng,
	linux-staging, linux-wireless, Gustavo A. R. Silva,
	Qinglang Miao, linux-block, Hulk Robot, clang-built-linux,
	netdev, dri-devel, Andrew Morton, linuxppc-dev, linux-kbuild,
	linux-hardening



Le 18/08/2021 à 08:05, Kees Cook a écrit :
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Instead of writing across a field boundary with memset(), move the call
> to just the array, and an explicit zeroing of the prior field.
> 
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Qinglang Miao <miaoqinglang@huawei.com>
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: Hulk Robot <hulkci@huawei.com>
> Cc: Wang Wensheng <wangwensheng4@huawei.com>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
> Link: https://lore.kernel.org/lkml/87czqsnmw9.fsf@mpe.ellerman.id.au
> ---
>   drivers/macintosh/smu.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
> index 94fb63a7b357..59ce431da7ef 100644
> --- a/drivers/macintosh/smu.c
> +++ b/drivers/macintosh/smu.c
> @@ -848,7 +848,8 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
>   	cmd->read = cmd->info.devaddr & 0x01;
>   	switch(cmd->info.type) {
>   	case SMU_I2C_TRANSFER_SIMPLE:
> -		memset(&cmd->info.sublen, 0, 4);
> +		cmd->info.sublen = 0;
> +		memset(&cmd->info.subaddr, 0, 3);

subaddr[] is a table, should the & be avoided ?
And while at it, why not use sizeof(subaddr) instead of 3 ?


>   		break;
>   	case SMU_I2C_TRANSFER_COMBINED:
>   		cmd->info.devaddr &= 0xfe;
> 

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status
  2021-08-18  6:05 ` [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status Kees Cook
@ 2021-08-18  7:08   ` Johannes Berg
  2021-08-18  8:06     ` Johannes Berg
  0 siblings, 1 reply; 116+ messages in thread
From: Johannes Berg @ 2021-08-18  7:08 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: David S. Miller, Jakub Kicinski, linux-wireless, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Tue, 2021-08-17 at 23:05 -0700, Kees Cook wrote:
> 
> @@ -275,12 +275,11 @@ static void carl9170_tx_release(struct kref *ref)
>  	if (WARN_ON_ONCE(!ar))
>  		return;
>  
> 
> 
> 
> -	BUILD_BUG_ON(
> -	    offsetof(struct ieee80211_tx_info, status.ack_signal) != 20);
> -
> -	memset(&txinfo->status.ack_signal, 0,
> -	       sizeof(struct ieee80211_tx_info) -
> -	       offsetof(struct ieee80211_tx_info, status.ack_signal));
> +	/*
> +	 * Should this call ieee80211_tx_info_clear_status() instead of clearing
> +	 * manually? txinfo->status.rates do not seem to be used here.
> +	 */

Since you insist, I went digging :)

It should not, carl9170_tx_fill_rateinfo() has filled the rate
information before we get to this point.

johannes


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status
  2021-08-18  7:08   ` Johannes Berg
@ 2021-08-18  8:06     ` Johannes Berg
  2021-08-18  9:05       ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Johannes Berg @ 2021-08-18  8:06 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: David S. Miller, Jakub Kicinski, linux-wireless, netdev,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, 2021-08-18 at 09:08 +0200, Johannes Berg wrote:
> On Tue, 2021-08-17 at 23:05 -0700, Kees Cook wrote:
> > 
> > @@ -275,12 +275,11 @@ static void carl9170_tx_release(struct kref *ref)
> >  	if (WARN_ON_ONCE(!ar))
> >  		return;
> >  
> > 
> > 
> > 
> > -	BUILD_BUG_ON(
> > -	    offsetof(struct ieee80211_tx_info, status.ack_signal) != 20);
> > -
> > -	memset(&txinfo->status.ack_signal, 0,
> > -	       sizeof(struct ieee80211_tx_info) -
> > -	       offsetof(struct ieee80211_tx_info, status.ack_signal));
> > +	/*
> > +	 * Should this call ieee80211_tx_info_clear_status() instead of clearing
> > +	 * manually? txinfo->status.rates do not seem to be used here.
> > +	 */
> 
> Since you insist, I went digging :)
> 
> It should not, carl9170_tx_fill_rateinfo() has filled the rate
> information before we get to this point.

Otherwise, looks fine, FWIW.

Are you going to apply all of these together somewhere? I (we) can't,
since memset_after() doesn't exist yet.

johannes


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status
  2021-08-18  8:06     ` Johannes Berg
@ 2021-08-18  9:05       ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18  9:05 UTC (permalink / raw)
  To: Johannes Berg
  Cc: linux-kernel, David S. Miller, Jakub Kicinski, linux-wireless,
	netdev, Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 10:06:51AM +0200, Johannes Berg wrote:
> On Wed, 2021-08-18 at 09:08 +0200, Johannes Berg wrote:
> > On Tue, 2021-08-17 at 23:05 -0700, Kees Cook wrote:
> > > 
> > > @@ -275,12 +275,11 @@ static void carl9170_tx_release(struct kref *ref)
> > >  	if (WARN_ON_ONCE(!ar))
> > >  		return;
> > >  
> > > 
> > > 
> > > 
> > > -	BUILD_BUG_ON(
> > > -	    offsetof(struct ieee80211_tx_info, status.ack_signal) != 20);
> > > -
> > > -	memset(&txinfo->status.ack_signal, 0,
> > > -	       sizeof(struct ieee80211_tx_info) -
> > > -	       offsetof(struct ieee80211_tx_info, status.ack_signal));
> > > +	/*
> > > +	 * Should this call ieee80211_tx_info_clear_status() instead of clearing
> > > +	 * manually? txinfo->status.rates do not seem to be used here.
> > > +	 */
> > 
> > Since you insist, I went digging :)
> > 
> > It should not, carl9170_tx_fill_rateinfo() has filled the rate
> > information before we get to this point.

Ah-ha! Thanks for checking. I'll update the comment to explain the
rationale here.

> Otherwise, looks fine, FWIW.

Thanks!

> Are you going to apply all of these together somewhere? I (we) can't,
> since memset_after() doesn't exist yet.

Right, given the dependencies, I am expecting to just carry the whole
series, since the vast majority of it has no binary changes, etc. I'm
hoping to get it into -next soon, but we're uncomfortably close to the
merge window. :P

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct
  2021-08-18  6:05 ` [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct Kees Cook
  2021-08-18  6:35   ` Nikolay Borisov
@ 2021-08-18  9:28   ` David Sterba
  1 sibling, 0 replies; 116+ messages in thread
From: David Sterba @ 2021-08-18  9:28 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Chris Mason, Josef Bacik, David Sterba,
	linux-btrfs, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Tue, Aug 17, 2021 at 11:05:19PM -0700, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Use memset_startat() so memset() doesn't get confused about writing
> beyond the destination member that is intended to be the starting point
> of zeroing through the end of the struct.
> 
> Cc: Chris Mason <clm@fb.com>
> Cc: Josef Bacik <josef@toxicpanda.com>
> Cc: David Sterba <dsterba@suse.com>
> Cc: linux-btrfs@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Acked-by: David Sterba <dsterba@suse.com>

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 26/63] lib/string: Move helper functions out of string.c
  2021-08-18  6:04 ` [PATCH v2 26/63] lib/string: Move helper functions out of string.c Kees Cook
@ 2021-08-18  9:35   ` Andy Shevchenko
  0 siblings, 0 replies; 116+ messages in thread
From: Andy Shevchenko @ 2021-08-18  9:35 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Andy Shevchenko, Andrew Morton, Nick Desaulniers,
	Andy Lavr, Nathan Chancellor, Alexey Dobriyan, Stephen Rothwell,
	Bartosz Golaszewski, Gustavo A. R. Silva, Greg Kroah-Hartman,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Tue, Aug 17, 2021 at 11:04:56PM -0700, Kees Cook wrote:
> The core functions of string.c are those that may be implemented by
> per-architecture functions, or overloaded by FORTIFY_SOURCE. As a
> result, it needs to be built with __NO_FORTIFY. Without this, macros
> will collide with function declarations. This was accidentally working
> due to -ffreestanding (on some architectures). Make this deterministic
> by explicitly setting __NO_FORTIFY and move all the helper functions
> into string_helpers.c so that they gain the fortification coverage they
> had been missing.

No objections
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Cc: Andy Shevchenko <andy@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Andy Lavr <andy.lavr@gmail.com>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Alexey Dobriyan <adobriyan@gmail.com>
> Cc: Stephen Rothwell <sfr@canb.auug.org.au>
> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/arm/boot/compressed/string.c     |   1 +
>  arch/s390/lib/string.c                |   3 +
>  arch/x86/boot/compressed/misc.h       |   2 +
>  arch/x86/boot/compressed/pgtable_64.c |   2 +
>  arch/x86/lib/string_32.c              |   1 +
>  lib/string.c                          | 210 +-------------------------
>  lib/string_helpers.c                  | 193 +++++++++++++++++++++++
>  7 files changed, 208 insertions(+), 204 deletions(-)
> 
> diff --git a/arch/arm/boot/compressed/string.c b/arch/arm/boot/compressed/string.c
> index 8c0fa276d994..fcc678fce045 100644
> --- a/arch/arm/boot/compressed/string.c
> +++ b/arch/arm/boot/compressed/string.c
> @@ -5,6 +5,7 @@
>   * Small subset of simple string routines
>   */
>  
> +#define __NO_FORTIFY
>  #include <linux/string.h>
>  
>  /*
> diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
> index cfcdf76d6a95..392fb9f4f4db 100644
> --- a/arch/s390/lib/string.c
> +++ b/arch/s390/lib/string.c
> @@ -8,6 +8,9 @@
>   */
>  
>  #define IN_ARCH_STRING_C 1
> +#ifndef __NO_FORTIFY
> +# define __NO_FORTIFY
> +#endif
>  
>  #include <linux/types.h>
>  #include <linux/string.h>
> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index 31139256859f..49bde196da9b 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -14,6 +14,8 @@
>  #undef CONFIG_KASAN
>  #undef CONFIG_KASAN_GENERIC
>  
> +#define __NO_FORTIFY
> +
>  /* cpu_feature_enabled() cannot be used this early */
>  #define USE_EARLY_PGTABLE_L5
>  
> diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
> index 2a78746f5a4c..a1733319a22a 100644
> --- a/arch/x86/boot/compressed/pgtable_64.c
> +++ b/arch/x86/boot/compressed/pgtable_64.c
> @@ -1,3 +1,5 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include "misc.h"
>  #include <linux/efi.h>
>  #include <asm/e820/types.h>
>  #include <asm/processor.h>
> diff --git a/arch/x86/lib/string_32.c b/arch/x86/lib/string_32.c
> index d15fdae9656e..53b3f202267c 100644
> --- a/arch/x86/lib/string_32.c
> +++ b/arch/x86/lib/string_32.c
> @@ -11,6 +11,7 @@
>   * strings.
>   */
>  
> +#define __NO_FORTIFY
>  #include <linux/string.h>
>  #include <linux/export.h>
>  
> diff --git a/lib/string.c b/lib/string.c
> index 4fec38fc6e58..4e111d9dd6d5 100644
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -6,20 +6,15 @@
>   */
>  
>  /*
> - * stupid library routines.. The optimized versions should generally be found
> - * as inline code in <asm-xx/string.h>
> + * This file should be used only for "library" routines that may have
> + * alternative implementations on specific architectures (generally
> + * found in <asm-xx/string.h>), or get overloaded by FORTIFY_SOURCE.
> + * (Specifically, this file is built with __NO_FORTIFY.)
>   *
> - * These are buggy as well..
> - *
> - * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
> - * -  Added strsep() which will replace strtok() soon (because strsep() is
> - *    reentrant and should be faster). Use only strsep() in new code, please.
> - *
> - * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>,
> - *                    Matthew Hawkins <matt@mh.dropbear.id.au>
> - * -  Kissed strtok() goodbye
> + * Other helper functions should live in string_helpers.c.
>   */
>  
> +#define __NO_FORTIFY
>  #include <linux/types.h>
>  #include <linux/string.h>
>  #include <linux/ctype.h>
> @@ -254,40 +249,6 @@ ssize_t strscpy(char *dest, const char *src, size_t count)
>  EXPORT_SYMBOL(strscpy);
>  #endif
>  
> -/**
> - * strscpy_pad() - Copy a C-string into a sized buffer
> - * @dest: Where to copy the string to
> - * @src: Where to copy the string from
> - * @count: Size of destination buffer
> - *
> - * Copy the string, or as much of it as fits, into the dest buffer.  The
> - * behavior is undefined if the string buffers overlap.  The destination
> - * buffer is always %NUL terminated, unless it's zero-sized.
> - *
> - * If the source string is shorter than the destination buffer, zeros
> - * the tail of the destination buffer.
> - *
> - * For full explanation of why you may want to consider using the
> - * 'strscpy' functions please see the function docstring for strscpy().
> - *
> - * Returns:
> - * * The number of characters copied (not including the trailing %NUL)
> - * * -E2BIG if count is 0 or @src was truncated.
> - */
> -ssize_t strscpy_pad(char *dest, const char *src, size_t count)
> -{
> -	ssize_t written;
> -
> -	written = strscpy(dest, src, count);
> -	if (written < 0 || written == count - 1)
> -		return written;
> -
> -	memset(dest + written + 1, 0, count - written - 1);
> -
> -	return written;
> -}
> -EXPORT_SYMBOL(strscpy_pad);
> -
>  /**
>   * stpcpy - copy a string from src to dest returning a pointer to the new end
>   *          of dest, including src's %NUL-terminator. May overrun dest.
> @@ -530,46 +491,6 @@ char *strnchr(const char *s, size_t count, int c)
>  EXPORT_SYMBOL(strnchr);
>  #endif
>  
> -/**
> - * skip_spaces - Removes leading whitespace from @str.
> - * @str: The string to be stripped.
> - *
> - * Returns a pointer to the first non-whitespace character in @str.
> - */
> -char *skip_spaces(const char *str)
> -{
> -	while (isspace(*str))
> -		++str;
> -	return (char *)str;
> -}
> -EXPORT_SYMBOL(skip_spaces);
> -
> -/**
> - * strim - Removes leading and trailing whitespace from @s.
> - * @s: The string to be stripped.
> - *
> - * Note that the first trailing whitespace is replaced with a %NUL-terminator
> - * in the given string @s. Returns a pointer to the first non-whitespace
> - * character in @s.
> - */
> -char *strim(char *s)
> -{
> -	size_t size;
> -	char *end;
> -
> -	size = strlen(s);
> -	if (!size)
> -		return s;
> -
> -	end = s + size - 1;
> -	while (end >= s && isspace(*end))
> -		end--;
> -	*(end + 1) = '\0';
> -
> -	return skip_spaces(s);
> -}
> -EXPORT_SYMBOL(strim);
> -
>  #ifndef __HAVE_ARCH_STRLEN
>  /**
>   * strlen - Find the length of a string
> @@ -704,101 +625,6 @@ char *strsep(char **s, const char *ct)
>  EXPORT_SYMBOL(strsep);
>  #endif
>  
> -/**
> - * sysfs_streq - return true if strings are equal, modulo trailing newline
> - * @s1: one string
> - * @s2: another string
> - *
> - * This routine returns true iff two strings are equal, treating both
> - * NUL and newline-then-NUL as equivalent string terminations.  It's
> - * geared for use with sysfs input strings, which generally terminate
> - * with newlines but are compared against values without newlines.
> - */
> -bool sysfs_streq(const char *s1, const char *s2)
> -{
> -	while (*s1 && *s1 == *s2) {
> -		s1++;
> -		s2++;
> -	}
> -
> -	if (*s1 == *s2)
> -		return true;
> -	if (!*s1 && *s2 == '\n' && !s2[1])
> -		return true;
> -	if (*s1 == '\n' && !s1[1] && !*s2)
> -		return true;
> -	return false;
> -}
> -EXPORT_SYMBOL(sysfs_streq);
> -
> -/**
> - * match_string - matches given string in an array
> - * @array:	array of strings
> - * @n:		number of strings in the array or -1 for NULL terminated arrays
> - * @string:	string to match with
> - *
> - * This routine will look for a string in an array of strings up to the
> - * n-th element in the array or until the first NULL element.
> - *
> - * Historically the value of -1 for @n, was used to search in arrays that
> - * are NULL terminated. However, the function does not make a distinction
> - * when finishing the search: either @n elements have been compared OR
> - * the first NULL element was found.
> - *
> - * Return:
> - * index of a @string in the @array if matches, or %-EINVAL otherwise.
> - */
> -int match_string(const char * const *array, size_t n, const char *string)
> -{
> -	int index;
> -	const char *item;
> -
> -	for (index = 0; index < n; index++) {
> -		item = array[index];
> -		if (!item)
> -			break;
> -		if (!strcmp(item, string))
> -			return index;
> -	}
> -
> -	return -EINVAL;
> -}
> -EXPORT_SYMBOL(match_string);
> -
> -/**
> - * __sysfs_match_string - matches given string in an array
> - * @array: array of strings
> - * @n: number of strings in the array or -1 for NULL terminated arrays
> - * @str: string to match with
> - *
> - * Returns index of @str in the @array or -EINVAL, just like match_string().
> - * Uses sysfs_streq instead of strcmp for matching.
> - *
> - * This routine will look for a string in an array of strings up to the
> - * n-th element in the array or until the first NULL element.
> - *
> - * Historically the value of -1 for @n, was used to search in arrays that
> - * are NULL terminated. However, the function does not make a distinction
> - * when finishing the search: either @n elements have been compared OR
> - * the first NULL element was found.
> - */
> -int __sysfs_match_string(const char * const *array, size_t n, const char *str)
> -{
> -	const char *item;
> -	int index;
> -
> -	for (index = 0; index < n; index++) {
> -		item = array[index];
> -		if (!item)
> -			break;
> -		if (sysfs_streq(item, str))
> -			return index;
> -	}
> -
> -	return -EINVAL;
> -}
> -EXPORT_SYMBOL(__sysfs_match_string);
> -
>  #ifndef __HAVE_ARCH_MEMSET
>  /**
>   * memset - Fill a region of memory with the given value
> @@ -1221,27 +1047,3 @@ void *memchr_inv(const void *start, int c, size_t bytes)
>  	return check_bytes8(start, value, bytes % 8);
>  }
>  EXPORT_SYMBOL(memchr_inv);
> -
> -/**
> - * strreplace - Replace all occurrences of character in string.
> - * @s: The string to operate on.
> - * @old: The character being replaced.
> - * @new: The character @old is replaced with.
> - *
> - * Returns pointer to the nul byte at the end of @s.
> - */
> -char *strreplace(char *s, char old, char new)
> -{
> -	for (; *s; ++s)
> -		if (*s == old)
> -			*s = new;
> -	return s;
> -}
> -EXPORT_SYMBOL(strreplace);
> -
> -void fortify_panic(const char *name)
> -{
> -	pr_emerg("detected buffer overflow in %s\n", name);
> -	BUG();
> -}
> -EXPORT_SYMBOL(fortify_panic);
> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
> index 3806a52ce697..bde13612c25d 100644
> --- a/lib/string_helpers.c
> +++ b/lib/string_helpers.c
> @@ -696,3 +696,196 @@ void kfree_strarray(char **array, size_t n)
>  	kfree(array);
>  }
>  EXPORT_SYMBOL_GPL(kfree_strarray);
> +
> +/**
> + * strscpy_pad() - Copy a C-string into a sized buffer
> + * @dest: Where to copy the string to
> + * @src: Where to copy the string from
> + * @count: Size of destination buffer
> + *
> + * Copy the string, or as much of it as fits, into the dest buffer.  The
> + * behavior is undefined if the string buffers overlap.  The destination
> + * buffer is always %NUL terminated, unless it's zero-sized.
> + *
> + * If the source string is shorter than the destination buffer, zeros
> + * the tail of the destination buffer.
> + *
> + * For full explanation of why you may want to consider using the
> + * 'strscpy' functions please see the function docstring for strscpy().
> + *
> + * Returns:
> + * * The number of characters copied (not including the trailing %NUL)
> + * * -E2BIG if count is 0 or @src was truncated.
> + */
> +ssize_t strscpy_pad(char *dest, const char *src, size_t count)
> +{
> +	ssize_t written;
> +
> +	written = strscpy(dest, src, count);
> +	if (written < 0 || written == count - 1)
> +		return written;
> +
> +	memset(dest + written + 1, 0, count - written - 1);
> +
> +	return written;
> +}
> +EXPORT_SYMBOL(strscpy_pad);
> +
> +/**
> + * skip_spaces - Removes leading whitespace from @str.
> + * @str: The string to be stripped.
> + *
> + * Returns a pointer to the first non-whitespace character in @str.
> + */
> +char *skip_spaces(const char *str)
> +{
> +	while (isspace(*str))
> +		++str;
> +	return (char *)str;
> +}
> +EXPORT_SYMBOL(skip_spaces);
> +
> +/**
> + * strim - Removes leading and trailing whitespace from @s.
> + * @s: The string to be stripped.
> + *
> + * Note that the first trailing whitespace is replaced with a %NUL-terminator
> + * in the given string @s. Returns a pointer to the first non-whitespace
> + * character in @s.
> + */
> +char *strim(char *s)
> +{
> +	size_t size;
> +	char *end;
> +
> +	size = strlen(s);
> +	if (!size)
> +		return s;
> +
> +	end = s + size - 1;
> +	while (end >= s && isspace(*end))
> +		end--;
> +	*(end + 1) = '\0';
> +
> +	return skip_spaces(s);
> +}
> +EXPORT_SYMBOL(strim);
> +
> +/**
> + * sysfs_streq - return true if strings are equal, modulo trailing newline
> + * @s1: one string
> + * @s2: another string
> + *
> + * This routine returns true iff two strings are equal, treating both
> + * NUL and newline-then-NUL as equivalent string terminations.  It's
> + * geared for use with sysfs input strings, which generally terminate
> + * with newlines but are compared against values without newlines.
> + */
> +bool sysfs_streq(const char *s1, const char *s2)
> +{
> +	while (*s1 && *s1 == *s2) {
> +		s1++;
> +		s2++;
> +	}
> +
> +	if (*s1 == *s2)
> +		return true;
> +	if (!*s1 && *s2 == '\n' && !s2[1])
> +		return true;
> +	if (*s1 == '\n' && !s1[1] && !*s2)
> +		return true;
> +	return false;
> +}
> +EXPORT_SYMBOL(sysfs_streq);
> +
> +/**
> + * match_string - matches given string in an array
> + * @array:	array of strings
> + * @n:		number of strings in the array or -1 for NULL terminated arrays
> + * @string:	string to match with
> + *
> + * This routine will look for a string in an array of strings up to the
> + * n-th element in the array or until the first NULL element.
> + *
> + * Historically the value of -1 for @n, was used to search in arrays that
> + * are NULL terminated. However, the function does not make a distinction
> + * when finishing the search: either @n elements have been compared OR
> + * the first NULL element was found.
> + *
> + * Return:
> + * index of a @string in the @array if matches, or %-EINVAL otherwise.
> + */
> +int match_string(const char * const *array, size_t n, const char *string)
> +{
> +	int index;
> +	const char *item;
> +
> +	for (index = 0; index < n; index++) {
> +		item = array[index];
> +		if (!item)
> +			break;
> +		if (!strcmp(item, string))
> +			return index;
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL(match_string);
> +
> +/**
> + * __sysfs_match_string - matches given string in an array
> + * @array: array of strings
> + * @n: number of strings in the array or -1 for NULL terminated arrays
> + * @str: string to match with
> + *
> + * Returns index of @str in the @array or -EINVAL, just like match_string().
> + * Uses sysfs_streq instead of strcmp for matching.
> + *
> + * This routine will look for a string in an array of strings up to the
> + * n-th element in the array or until the first NULL element.
> + *
> + * Historically the value of -1 for @n, was used to search in arrays that
> + * are NULL terminated. However, the function does not make a distinction
> + * when finishing the search: either @n elements have been compared OR
> + * the first NULL element was found.
> + */
> +int __sysfs_match_string(const char * const *array, size_t n, const char *str)
> +{
> +	const char *item;
> +	int index;
> +
> +	for (index = 0; index < n; index++) {
> +		item = array[index];
> +		if (!item)
> +			break;
> +		if (sysfs_streq(item, str))
> +			return index;
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL(__sysfs_match_string);
> +
> +/**
> + * strreplace - Replace all occurrences of character in string.
> + * @s: The string to operate on.
> + * @old: The character being replaced.
> + * @new: The character @old is replaced with.
> + *
> + * Returns pointer to the nul byte at the end of @s.
> + */
> +char *strreplace(char *s, char old, char new)
> +{
> +	for (; *s; ++s)
> +		if (*s == old)
> +			*s = new;
> +	return s;
> +}
> +EXPORT_SYMBOL(strreplace);
> +
> +void fortify_panic(const char *name)
> +{
> +	pr_emerg("detected buffer overflow in %s\n", name);
> +	BUG();
> +}
> +EXPORT_SYMBOL(fortify_panic);
> -- 
> 2.30.2
> 

-- 
With Best Regards,
Andy Shevchenko



^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 13/63] iommu/amd: Use struct_group() for memcpy() region
  2021-08-18  6:04 ` [PATCH v2 13/63] iommu/amd: " Kees Cook
@ 2021-08-18 11:34   ` Joerg Roedel
  0 siblings, 0 replies; 116+ messages in thread
From: Joerg Roedel @ 2021-08-18 11:34 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Will Deacon, iommu, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Tue, Aug 17, 2021 at 11:04:43PM -0700, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), memmove(), and memset(), avoid
> intentionally writing across neighboring fields.
> 
> Use struct_group() in struct ivhd_entry around members ext and hidh, so
> they can be referenced together. This will allow memcpy() and sizeof()
> to more easily reason about sizes, improve readability, and avoid future
> warnings about writing beyond the end of ext.
> 
> "pahole" shows no size nor member offset changes to struct ivhd_entry.
> "objdump -d" shows no object code changes.
> 
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Will Deacon <will@kernel.org>
> Cc: iommu@lists.linux-foundation.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Acked-by: Joerg Roedel <jroedel@suse.de>


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 18/63] drm/amd/pm: Use struct_group() for memcpy() region
  2021-08-18  6:04 ` [PATCH v2 18/63] drm/amd/pm: " Kees Cook
@ 2021-08-18 11:42   ` Lazar, Lijo
  2021-08-18 23:59     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Lazar, Lijo @ 2021-08-18 11:42 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: Christian König, Pan, Xinhui, David Airlie, Daniel Vetter,
	Hawking Zhang, Feifei Xu, Likun Gao, Jiawei Gu, Evan Quan,
	amd-gfx, dri-devel, Alex Deucher, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening


On 8/18/2021 11:34 AM, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), memmove(), and memset(), avoid
> intentionally writing across neighboring fields.
> 
> Use struct_group() in structs:
> 	struct atom_smc_dpm_info_v4_5
> 	struct atom_smc_dpm_info_v4_6
> 	struct atom_smc_dpm_info_v4_7
> 	struct atom_smc_dpm_info_v4_10
> 	PPTable_t
> so the grouped members can be referenced together. This will allow
> memcpy() and sizeof() to more easily reason about sizes, improve
> readability, and avoid future warnings about writing beyond the end of
> the first member.
> 
> "pahole" shows no size nor member offset changes to any structs.
> "objdump -d" shows no object code changes.
> 
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> Cc: Feifei Xu <Feifei.Xu@amd.com>
> Cc: Lijo Lazar <lijo.lazar@amd.com>
> Cc: Likun Gao <Likun.Gao@amd.com>
> Cc: Jiawei Gu <Jiawei.Gu@amd.com>
> Cc: Evan Quan <evan.quan@amd.com>
> Cc: amd-gfx@lists.freedesktop.org
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Acked-by: Alex Deucher <alexander.deucher@amd.com>
> Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2FCADnq5_Npb8uYvd%2BR4UHgf-w8-cQj3JoODjviJR_Y9w9wqJ71mQ%40mail.gmail.com&amp;data=04%7C01%7Clijo.lazar%40amd.com%7C92b8d2f072f0444b9f8508d9620f6971%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637648640625729624%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=rKh5LUXCRUsorYM3kSpG2tkB%2Fczwl9I9EBnWBCtbg6Q%3D&amp;reserved=0
> ---
>   drivers/gpu/drm/amd/include/atomfirmware.h           |  9 ++++++++-
>   .../gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h    |  3 ++-
>   drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h  |  3 ++-
>   .../gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h   |  3 ++-

Hi Kees,

The headers which define these structs are firmware/VBIOS interfaces and 
are picked directly from those components. There are difficulties in 
grouping them to structs at the original source as that involves other 
component changes.

The driver_if_* files updates are frequent and it is error prone to 
manually group them each time we pick them for any update. Our usage of 
memcpy in this way is restricted only to a very few places.

As another option - is it possible to have a helper function/macro like 
memcpy_fortify() which takes the extra arguments and does the extra 
compile time checks? We will use the helper whenever we have such kind 
of usage.

Thanks,
Lijo

>   drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c    |  6 +++---
>   drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c      | 12 ++++++++----
>   drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c   |  6 +++---
>   7 files changed, 28 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/include/atomfirmware.h b/drivers/gpu/drm/amd/include/atomfirmware.h
> index 44955458fe38..7bf3edf15410 100644
> --- a/drivers/gpu/drm/amd/include/atomfirmware.h
> +++ b/drivers/gpu/drm/amd/include/atomfirmware.h
> @@ -2081,6 +2081,7 @@ struct atom_smc_dpm_info_v4_5
>   {
>     struct   atom_common_table_header  table_header;
>       // SECTION: BOARD PARAMETERS
> +  struct_group(dpm_info,
>       // I2C Control
>     struct smudpm_i2c_controller_config_v2  I2cControllers[8];
>   
> @@ -2159,7 +2160,7 @@ struct atom_smc_dpm_info_v4_5
>     uint32_t MvddRatio; // This is used for MVDD Vid workaround. It has 16 fractional bits (Q16.16)
>     
>     uint32_t     BoardReserved[9];
> -
> +  );
>   };
>   
>   struct atom_smc_dpm_info_v4_6
> @@ -2168,6 +2169,7 @@ struct atom_smc_dpm_info_v4_6
>     // section: board parameters
>     uint32_t     i2c_padding[3];   // old i2c control are moved to new area
>   
> +  struct_group(dpm_info,
>     uint16_t     maxvoltagestepgfx; // in mv(q2) max voltage step that smu will request. multiple steps are taken if voltage change exceeds this value.
>     uint16_t     maxvoltagestepsoc; // in mv(q2) max voltage step that smu will request. multiple steps are taken if voltage change exceeds this value.
>   
> @@ -2246,12 +2248,14 @@ struct atom_smc_dpm_info_v4_6
>   
>     // reserved
>     uint32_t   boardreserved[10];
> +  );
>   };
>   
>   struct atom_smc_dpm_info_v4_7
>   {
>     struct   atom_common_table_header  table_header;
>       // SECTION: BOARD PARAMETERS
> +  struct_group(dpm_info,
>       // I2C Control
>     struct smudpm_i2c_controller_config_v2  I2cControllers[8];
>   
> @@ -2348,6 +2352,7 @@ struct atom_smc_dpm_info_v4_7
>     uint8_t      Padding8_Psi2;
>   
>     uint32_t     BoardReserved[5];
> +  );
>   };
>   
>   struct smudpm_i2c_controller_config_v3
> @@ -2478,6 +2483,7 @@ struct atom_smc_dpm_info_v4_10
>     struct   atom_common_table_header  table_header;
>   
>     // SECTION: BOARD PARAMETERS
> +  struct_group(dpm_info,
>     // Telemetry Settings
>     uint16_t GfxMaxCurrent; // in Amps
>     uint8_t   GfxOffset;     // in Amps
> @@ -2524,6 +2530,7 @@ struct atom_smc_dpm_info_v4_10
>     uint16_t spare5;
>   
>     uint32_t reserved[16];
> +  );
>   };
>   
>   /*
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> index 43d43d6addc0..8093a98800c3 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> @@ -643,6 +643,7 @@ typedef struct {
>     // SECTION: BOARD PARAMETERS
>   
>     // SVI2 Board Parameters
> +  struct_group(v4_6,
>     uint16_t     MaxVoltageStepGfx; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
>     uint16_t     MaxVoltageStepSoc; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
>   
> @@ -728,10 +729,10 @@ typedef struct {
>     uint32_t     BoardVoltageCoeffB;    // decode by /1000
>   
>     uint32_t     BoardReserved[7];
> +  );
>   
>     // Padding for MMHUB - do not modify this
>     uint32_t     MmHubPadding[8]; // SMU internal use
> -
>   } PPTable_t;
>   
>   typedef struct {
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
> index 04752ade1016..0b4e6e907e95 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
> @@ -725,6 +725,7 @@ typedef struct {
>     uint32_t     Reserved[8];
>   
>     // SECTION: BOARD PARAMETERS
> +  struct_group(v4,
>     // I2C Control
>     I2cControllerConfig_t  I2cControllers[NUM_I2C_CONTROLLERS];
>   
> @@ -809,10 +810,10 @@ typedef struct {
>     uint8_t      Padding8_Loadline;
>   
>     uint32_t     BoardReserved[8];
> +  );
>   
>     // Padding for MMHUB - do not modify this
>     uint32_t     MmHubPadding[8]; // SMU internal use
> -
>   } PPTable_t;
>   
>   typedef struct {
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h b/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
> index a017983ff1fa..5056d3728da8 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
> @@ -390,6 +390,7 @@ typedef struct {
>     uint32_t spare3[14];
>   
>     // SECTION: BOARD PARAMETERS
> +  struct_group(v4_10,
>     // Telemetry Settings
>     uint16_t GfxMaxCurrent; // in Amps
>     int8_t   GfxOffset;     // in Amps
> @@ -444,7 +445,7 @@ typedef struct {
>   
>     //reserved
>     uint32_t reserved[14];
> -
> +  );
>   } PPTable_t;
>   
>   typedef struct {
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
> index 8ab58781ae13..341adf209240 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
> @@ -463,11 +463,11 @@ static int arcturus_append_powerplay_table(struct smu_context *smu)
>   			smc_dpm_table->table_header.format_revision,
>   			smc_dpm_table->table_header.content_revision);
>   
> +	BUILD_BUG_ON(sizeof(smc_pptable->v4_6) != sizeof(smc_dpm_table->dpm_info));
>   	if ((smc_dpm_table->table_header.format_revision == 4) &&
>   	    (smc_dpm_table->table_header.content_revision == 6))
> -		memcpy(&smc_pptable->MaxVoltageStepGfx,
> -		       &smc_dpm_table->maxvoltagestepgfx,
> -		       sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_6, maxvoltagestepgfx));
> +		memcpy(&smc_pptable->v4_6, &smc_dpm_table->dpm_info,
> +		       sizeof(smc_dpm_table->dpm_info));
>   
>   	return 0;
>   }
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
> index 2e5d3669652b..e8b6e25a7815 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
> @@ -431,16 +431,20 @@ static int navi10_append_powerplay_table(struct smu_context *smu)
>   
>   	switch (smc_dpm_table->table_header.content_revision) {
>   	case 5: /* nv10 and nv14 */
> -		memcpy(smc_pptable->I2cControllers, smc_dpm_table->I2cControllers,
> -			sizeof(*smc_dpm_table) - sizeof(smc_dpm_table->table_header));
> +		BUILD_BUG_ON(sizeof(smc_pptable->v4) !=
> +			     sizeof(smc_dpm_table->dpm_info));
> +		memcpy(&smc_pptable->v4, &smc_dpm_table->dpm_info,
> +		       sizeof(smc_dpm_table->dpm_info));
>   		break;
>   	case 7: /* nv12 */
>   		ret = amdgpu_atombios_get_data_table(adev, index, NULL, NULL, NULL,
>   					      (uint8_t **)&smc_dpm_table_v4_7);
>   		if (ret)
>   			return ret;
> -		memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
> -			sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));
> +		BUILD_BUG_ON(sizeof(smc_pptable->v4) !=
> +			     sizeof(smc_dpm_table_v4_7->dpm_info));
> +		memcpy(&smc_pptable->v4, &smc_dpm_table_v4_7->dpm_info,
> +		       sizeof(smc_dpm_table_v4_7->dpm_info));
>   		break;
>   	default:
>   		dev_err(smu->adev->dev, "smc_dpm_info with unsupported content revision %d!\n",
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
> index c8eefacfdd37..492ba37bc514 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
> @@ -407,11 +407,11 @@ static int aldebaran_append_powerplay_table(struct smu_context *smu)
>   			smc_dpm_table->table_header.format_revision,
>   			smc_dpm_table->table_header.content_revision);
>   
> +	BUILD_BUG_ON(sizeof(smc_pptable->v4_10) != sizeof(smc_dpm_table->dpm_info));
>   	if ((smc_dpm_table->table_header.format_revision == 4) &&
>   	    (smc_dpm_table->table_header.content_revision == 10))
> -		memcpy(&smc_pptable->GfxMaxCurrent,
> -		       &smc_dpm_table->GfxMaxCurrent,
> -		       sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_10, GfxMaxCurrent));
> +		memcpy(&smc_pptable->v4_10, &smc_dpm_table->dpm_info,
> +		       sizeof(smc_dpm_table->dpm_info));
>   	return 0;
>   }
>   
> 

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 25/63] compiler_types.h: Remove __compiletime_object_size()
  2021-08-18  6:04 ` [PATCH v2 25/63] compiler_types.h: Remove __compiletime_object_size() Kees Cook
@ 2021-08-18 13:02   ` Miguel Ojeda
  0 siblings, 0 replies; 116+ messages in thread
From: Miguel Ojeda @ 2021-08-18 13:02 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Nick Desaulniers, Nathan Chancellor, Miguel Ojeda,
	Sedat Dilek, Will Deacon, Marco Elver, Arvind Sankar,
	Masahiro Yamada, Luc Van Oostenryck, Andrew Morton,
	Sami Tolvanen, Thomas Gleixner, Gabriel Krisman Bertazi,
	Andy Lutomirski, Oleg Nesterov, Gustavo A. R. Silva,
	Greg Kroah-Hartman, linux-wireless, Network Development,
	dri-devel, linux-staging, linux-block, Linux Kbuild mailing list,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 8:14 AM Kees Cook <keescook@chromium.org> wrote:
>
> Since all compilers support __builtin_object_size(), and there is only
> one user of __compiletime_object_size, remove it to avoid the needless
> indirection. This lets Clang reason about check_copy_size() correctly.

Sounds good to me, the indirection is making things more complex than
they need to be.

Reviewed-by: Miguel Ojeda <ojeda@kernel.org>

Cheers,
Miguel

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator
  2021-08-18  6:05 ` [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator Kees Cook
@ 2021-08-18 13:33   ` Steven Rostedt
  2021-08-18 16:21     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Steven Rostedt @ 2021-08-18 13:33 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Ingo Molnar, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Tue, 17 Aug 2021 23:05:20 -0700
Kees Cook <keescook@chromium.org> wrote:

> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Use memset_startat() to avoid confusing memset() about writing beyond
> the target struct member.
> 
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  kernel/trace/trace.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 13587e771567..9ff8c31975cd 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -6691,9 +6691,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
>  		cnt = PAGE_SIZE - 1;
>  
>  	/* reset all but tr, trace, and overruns */
> -	memset(&iter->seq, 0,
> -	       sizeof(struct trace_iterator) -
> -	       offsetof(struct trace_iterator, seq));
> +	memset_startat(iter, 0, seq);

I can't find memset_startat() in mainline nor linux-next. I don't see it
in this thread either, but since this has 63 patches, I could have
easily missed it.

This change really should belong to a patch set that just introduces
memset_startat() (and perhaps memset_after()) and then updates all the
places that should use it. That way I can give it a proper review. In
other words, you should break this patch set up into smaller, more
digestible portions for the reviewers.

Thanks,

-- Steve



>  	cpumask_clear(iter->started);
>  	trace_seq_init(&iter->seq);
>  	iter->pos = -1;


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache
  2021-08-18  6:05 ` [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache Kees Cook
@ 2021-08-18 15:11   ` Sean Christopherson
  2021-08-18 16:23     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Sean Christopherson @ 2021-08-18 15:11 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Paolo Bonzini, Vitaly Kuznetsov, Wanpeng Li,
	Jim Mattson, Joerg Roedel, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, kvm, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Tue, Aug 17, 2021, Kees Cook wrote:
>  arch/x86/kvm/emulate.c     |  3 +--
>  arch/x86/kvm/kvm_emulate.h | 19 +++++++++++--------
>  2 files changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index 2837110e66ed..2608a047e769 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -5377,8 +5377,7 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
>  
>  void init_decode_cache(struct x86_emulate_ctxt *ctxt)
>  {
> -	memset(&ctxt->rip_relative, 0,
> -	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
> +	memset(&ctxt->decode_cache, 0, sizeof(ctxt->decode_cache));
>  
>  	ctxt->io_read.pos = 0;
>  	ctxt->io_read.end = 0;
> diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
> index 68b420289d7e..9b8afcb8ad39 100644
> --- a/arch/x86/kvm/kvm_emulate.h
> +++ b/arch/x86/kvm/kvm_emulate.h
> @@ -341,14 +341,17 @@ struct x86_emulate_ctxt {
>  	 * the rest are initialized unconditionally in x86_decode_insn
>  	 * or elsewhere
>  	 */
> -	bool rip_relative;
> -	u8 rex_prefix;
> -	u8 lock_prefix;
> -	u8 rep_prefix;
> -	/* bitmaps of registers in _regs[] that can be read */
> -	u32 regs_valid;
> -	/* bitmaps of registers in _regs[] that have been written */
> -	u32 regs_dirty;
> +	struct_group(decode_cache,

This is somewhat misleading because half of this struct is the so called "decode
cache", not just these six fields.

KVM's "optimization" is quite ridiculous as this has never been such a hot path
that saving a few mov instructions would be noticeable.  And hilariously, the
"optimization" is completely unnecessary because both gcc and clang are clever
enough to batch the first five into a movq even when zeroing the fields individually.

So, I would much prefer to go with the following:

From dbdca1f4cd01fee418c252e54c360d518b2b1ad6 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Wed, 18 Aug 2021 08:03:08 -0700
Subject: [PATCH] KVM: x86: Replace memset() "optimization" with normal
 per-field writes

Explicitly zero select fields in the emulator's decode cache instead of
zeroing the fields via a gross memset() that spans six fields.  gcc and
clang are both clever enough to batch the first five fields into a single
quadword MOV, i.e. memset() and individually zeroing generate identical
code.

Removing the wart also prepares KVM for FORTIFY_SOURCE performing
compile-time and run-time field bounds checking for memset().

No functional change intended.

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/emulate.c     | 9 +++++++--
 arch/x86/kvm/kvm_emulate.h | 6 +-----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2837110e66ed..bf81fd017e7f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5377,8 +5377,13 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)

 void init_decode_cache(struct x86_emulate_ctxt *ctxt)
 {
-	memset(&ctxt->rip_relative, 0,
-	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
+	/* Clear fields that are set conditionally but read without a guard. */
+	ctxt->rip_relative = false;
+	ctxt->rex_prefix = 0;
+	ctxt->lock_prefix = 0;
+	ctxt->rep_prefix = 0;
+	ctxt->regs_valid = 0;
+	ctxt->regs_dirty = 0;

 	ctxt->io_read.pos = 0;
 	ctxt->io_read.end = 0;
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 68b420289d7e..bc1fecacccd4 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -336,11 +336,7 @@ struct x86_emulate_ctxt {
 		fastop_t fop;
 	};
 	int (*check_perm)(struct x86_emulate_ctxt *ctxt);
-	/*
-	 * The following six fields are cleared together,
-	 * the rest are initialized unconditionally in x86_decode_insn
-	 * or elsewhere
-	 */
+
 	bool rip_relative;
 	u8 rex_prefix;
 	u8 lock_prefix;
--
2.33.0.rc1.237.g0d66db33f3-goog

> +		bool rip_relative;
> +		u8 rex_prefix;
> +		u8 lock_prefix;
> +		u8 rep_prefix;
> +		/* bitmaps of registers in _regs[] that can be read */
> +		u32 regs_valid;
> +		/* bitmaps of registers in _regs[] that have been written */
> +		u32 regs_dirty;
> +	);
> +
>  	/* modrm */
>  	u8 modrm;
>  	u8 modrm_mod;
> -- 
> 2.30.2
> 

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator
  2021-08-18 13:33   ` Steven Rostedt
@ 2021-08-18 16:21     ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18 16:21 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: linux-kernel, Ingo Molnar, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 09:33:49AM -0400, Steven Rostedt wrote:
> On Tue, 17 Aug 2021 23:05:20 -0700
> Kees Cook <keescook@chromium.org> wrote:
> 
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memset(), avoid intentionally writing across
> > neighboring fields.
> > 
> > Use memset_startat() to avoid confusing memset() about writing beyond
> > the target struct member.
> > 
> > Cc: Steven Rostedt <rostedt@goodmis.org>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  kernel/trace/trace.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index 13587e771567..9ff8c31975cd 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -6691,9 +6691,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
> >  		cnt = PAGE_SIZE - 1;
> >  
> >  	/* reset all but tr, trace, and overruns */
> > -	memset(&iter->seq, 0,
> > -	       sizeof(struct trace_iterator) -
> > -	       offsetof(struct trace_iterator, seq));
> > +	memset_startat(iter, 0, seq);
> 
> I can't find memset_startat() in mainline nor linux-next. I don't see it
> in this thread either, but since this has 63 patches, I could have
> easily missed it.

Sorry, it isn't called out in the Subject, but it's part of this patch:
https://lore.kernel.org/lkml/20210818060533.3569517-38-keescook@chromium.org/

> This change really should belong to a patch set that just introduces
> memset_startat() (and perhaps memset_after()) and then updates all the
> places that should use it. That way I can give it a proper review. In
> other words, you should break this patch set up into smaller, more
> digestible portions for the reviewers.

I will split memset_after() and memset_startat() introduction patches. I
already split up each use into individual cases, so that those changes
could be checked one step at a time for differences in pahole struct
layout and object code.

Thanks for taking a look!

-Kees

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache
  2021-08-18 15:11   ` Sean Christopherson
@ 2021-08-18 16:23     ` Kees Cook
  2021-08-18 22:53       ` Sean Christopherson
  0 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18 16:23 UTC (permalink / raw)
  To: Sean Christopherson
  Cc: linux-kernel, Paolo Bonzini, Vitaly Kuznetsov, Wanpeng Li,
	Jim Mattson, Joerg Roedel, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, kvm, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 03:11:28PM +0000, Sean Christopherson wrote:
> On Tue, Aug 17, 2021, Kees Cook wrote:
> >  arch/x86/kvm/emulate.c     |  3 +--
> >  arch/x86/kvm/kvm_emulate.h | 19 +++++++++++--------
> >  2 files changed, 12 insertions(+), 10 deletions(-)
> > 
> > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> > index 2837110e66ed..2608a047e769 100644
> > --- a/arch/x86/kvm/emulate.c
> > +++ b/arch/x86/kvm/emulate.c
> > @@ -5377,8 +5377,7 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
> >  
> >  void init_decode_cache(struct x86_emulate_ctxt *ctxt)
> >  {
> > -	memset(&ctxt->rip_relative, 0,
> > -	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
> > +	memset(&ctxt->decode_cache, 0, sizeof(ctxt->decode_cache));
> >  
> >  	ctxt->io_read.pos = 0;
> >  	ctxt->io_read.end = 0;
> > diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
> > index 68b420289d7e..9b8afcb8ad39 100644
> > --- a/arch/x86/kvm/kvm_emulate.h
> > +++ b/arch/x86/kvm/kvm_emulate.h
> > @@ -341,14 +341,17 @@ struct x86_emulate_ctxt {
> >  	 * the rest are initialized unconditionally in x86_decode_insn
> >  	 * or elsewhere
> >  	 */
> > -	bool rip_relative;
> > -	u8 rex_prefix;
> > -	u8 lock_prefix;
> > -	u8 rep_prefix;
> > -	/* bitmaps of registers in _regs[] that can be read */
> > -	u32 regs_valid;
> > -	/* bitmaps of registers in _regs[] that have been written */
> > -	u32 regs_dirty;
> > +	struct_group(decode_cache,
> 
> This is somewhat misleading because half of this struct is the so called "decode
> cache", not just these six fields.
> 
> KVM's "optimization" is quite ridiculous as this has never been such a hot path
> that saving a few mov instructions would be noticeable.  And hilariously, the
> "optimization" is completely unnecessary because both gcc and clang are clever
> enough to batch the first five into a movq even when zeroing the fields individually.
> 
> So, I would much prefer to go with the following:

Sounds good to me!

> 
> From dbdca1f4cd01fee418c252e54c360d518b2b1ad6 Mon Sep 17 00:00:00 2001
> From: Sean Christopherson <seanjc@google.com>
> Date: Wed, 18 Aug 2021 08:03:08 -0700
> Subject: [PATCH] KVM: x86: Replace memset() "optimization" with normal
>  per-field writes
> 
> Explicitly zero select fields in the emulator's decode cache instead of
> zeroing the fields via a gross memset() that spans six fields.  gcc and
> clang are both clever enough to batch the first five fields into a single
> quadword MOV, i.e. memset() and individually zeroing generate identical
> code.
> 
> Removing the wart also prepares KVM for FORTIFY_SOURCE performing
> compile-time and run-time field bounds checking for memset().
> 
> No functional change intended.
> 
> Reported-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

Do you want me to take this patch into my tree, or do you want to carry
it for KVM directly?

Thanks!

-Kees

> ---
>  arch/x86/kvm/emulate.c     | 9 +++++++--
>  arch/x86/kvm/kvm_emulate.h | 6 +-----
>  2 files changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index 2837110e66ed..bf81fd017e7f 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -5377,8 +5377,13 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
> 
>  void init_decode_cache(struct x86_emulate_ctxt *ctxt)
>  {
> -	memset(&ctxt->rip_relative, 0,
> -	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
> +	/* Clear fields that are set conditionally but read without a guard. */
> +	ctxt->rip_relative = false;
> +	ctxt->rex_prefix = 0;
> +	ctxt->lock_prefix = 0;
> +	ctxt->rep_prefix = 0;
> +	ctxt->regs_valid = 0;
> +	ctxt->regs_dirty = 0;
> 
>  	ctxt->io_read.pos = 0;
>  	ctxt->io_read.end = 0;
> diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
> index 68b420289d7e..bc1fecacccd4 100644
> --- a/arch/x86/kvm/kvm_emulate.h
> +++ b/arch/x86/kvm/kvm_emulate.h
> @@ -336,11 +336,7 @@ struct x86_emulate_ctxt {
>  		fastop_t fop;
>  	};
>  	int (*check_perm)(struct x86_emulate_ctxt *ctxt);
> -	/*
> -	 * The following six fields are cleared together,
> -	 * the rest are initialized unconditionally in x86_decode_insn
> -	 * or elsewhere
> -	 */
> +
>  	bool rip_relative;
>  	u8 rex_prefix;
>  	u8 lock_prefix;
> --
> 2.33.0.rc1.237.g0d66db33f3-goog
> 
> > +		bool rip_relative;
> > +		u8 rex_prefix;
> > +		u8 lock_prefix;
> > +		u8 rep_prefix;
> > +		/* bitmaps of registers in _regs[] that can be read */
> > +		u32 regs_valid;
> > +		/* bitmaps of registers in _regs[] that have been written */
> > +		u32 regs_dirty;
> > +	);
> > +
> >  	/* modrm */
> >  	u8 modrm;
> >  	u8 modrm_mod;
> > -- 
> > 2.30.2
> > 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 27/63] fortify: Move remaining fortify helpers into fortify-string.h
  2021-08-18  6:04 ` [PATCH v2 27/63] fortify: Move remaining fortify helpers into fortify-string.h Kees Cook
@ 2021-08-18 19:05   ` Francis Laniel
  0 siblings, 0 replies; 116+ messages in thread
From: Francis Laniel @ 2021-08-18 19:05 UTC (permalink / raw)
  To: linux-kernel, Kees Cook
  Cc: Kees Cook, Andrew Morton, Daniel Axtens, Vincenzo Frascino,
	Andrey Konovalov, Dan Williams, Gustavo A. R. Silva,
	Greg Kroah-Hartman, linux-wireless, netdev, dri-devel,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

Hi.


Le mercredi 18 août 2021, 08:04:57 CEST Kees Cook a écrit :
> When commit a28a6e860c6c ("string.h: move fortified functions definitions
> in a dedicated header.") moved the fortify-specific code, some helpers
> were left behind. Moves the remaining fortify-specific helpers into
> fortify-string.h so they're together where they're used. This requires
> that any FORTIFY helper function prototypes be conditionally built to
> avoid "no prototype" warnings. Additionally removes unused helpers.
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Francis Laniel <laniel_francis@privacyrequired.com>
> Cc: Daniel Axtens <dja@axtens.net>
> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Cc: Andrey Konovalov <andreyknvl@google.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  include/linux/fortify-string.h | 7 +++++++
>  include/linux/string.h         | 9 ---------
>  lib/string_helpers.c           | 2 ++
>  3 files changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
> index c1be37437e77..7e67d02764db 100644
> --- a/include/linux/fortify-string.h
> +++ b/include/linux/fortify-string.h
> @@ -2,6 +2,13 @@
>  #ifndef _LINUX_FORTIFY_STRING_H_
>  #define _LINUX_FORTIFY_STRING_H_
> 
> +#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
> +#define __RENAME(x) __asm__(#x)
> +
> +void fortify_panic(const char *name) __noreturn __cold;
> +void __read_overflow(void) __compiletime_error("detected read beyond size
> of object (1st parameter)"); +void __read_overflow2(void)
> __compiletime_error("detected read beyond size of object (2nd parameter)");
> +void __write_overflow(void) __compiletime_error("detected write beyond
> size of object (1st parameter)");
> 
>  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
>  extern void *__underlying_memchr(const void *p, int c, __kernel_size_t
> size) __RENAME(memchr); diff --git a/include/linux/string.h
> b/include/linux/string.h
> index b48d2d28e0b1..9473f81b9db2 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -249,15 +249,6 @@ static inline const char *kbasename(const char *path)
>  	return tail ? tail + 1 : path;
>  }
> 
> -#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
> -#define __RENAME(x) __asm__(#x)
> -
> -void fortify_panic(const char *name) __noreturn __cold;
> -void __read_overflow(void) __compiletime_error("detected read beyond size
> of object passed as 1st parameter"); -void __read_overflow2(void)
> __compiletime_error("detected read beyond size of object passed as 2nd
> parameter"); -void __read_overflow3(void) __compiletime_error("detected
> read beyond size of object passed as 3rd parameter"); -void
> __write_overflow(void) __compiletime_error("detected write beyond size of
> object passed as 1st parameter"); -
>  #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) &&
> defined(CONFIG_FORTIFY_SOURCE) #include <linux/fortify-string.h>
>  #endif
> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
> index bde13612c25d..faa9d8e4e2c5 100644
> --- a/lib/string_helpers.c
> +++ b/lib/string_helpers.c
> @@ -883,9 +883,11 @@ char *strreplace(char *s, char old, char new)
>  }
>  EXPORT_SYMBOL(strreplace);
> 
> +#ifdef CONFIG_FORTIFY_SOURCE
>  void fortify_panic(const char *name)
>  {
>  	pr_emerg("detected buffer overflow in %s\n", name);
>  	BUG();
>  }
>  EXPORT_SYMBOL(fortify_panic);
> +#endif /* CONFIG_FORTIFY_SOURCE */

If I remember correctly, I let these helpers in string.h because I thought 
they could be used by code not related to fortify-string.h.

But you are right and I think it is better to have all the code related to one 
feature in the same place.
I am happy to see the kernel is fortifying, and this contribution is good, so 
here is what I can give:
Acked-by: Francis Laniel <laniel_francis@privacyrequired.com>


Best regards.



^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow
  2021-08-18  6:42   ` Christophe Leroy
@ 2021-08-18 22:30     ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18 22:30 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: linux-kernel, Rasmus Villemoes, Greg Kroah-Hartman,
	Wang Wensheng, linux-staging, linux-wireless,
	Gustavo A. R. Silva, Qinglang Miao, linux-block, Hulk Robot,
	clang-built-linux, netdev, dri-devel, Andrew Morton,
	linuxppc-dev, linux-kbuild, linux-hardening

On Wed, Aug 18, 2021 at 08:42:18AM +0200, Christophe Leroy wrote:
> 
> 
> Le 18/08/2021 à 08:05, Kees Cook a écrit :
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memset(), avoid intentionally writing across
> > neighboring fields.
> > 
> > Instead of writing across a field boundary with memset(), move the call
> > to just the array, and an explicit zeroing of the prior field.
> > 
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Qinglang Miao <miaoqinglang@huawei.com>
> > Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> > Cc: Hulk Robot <hulkci@huawei.com>
> > Cc: Wang Wensheng <wangwensheng4@huawei.com>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
> > Link: https://lore.kernel.org/lkml/87czqsnmw9.fsf@mpe.ellerman.id.au
> > ---
> >   drivers/macintosh/smu.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
> > index 94fb63a7b357..59ce431da7ef 100644
> > --- a/drivers/macintosh/smu.c
> > +++ b/drivers/macintosh/smu.c
> > @@ -848,7 +848,8 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
> >   	cmd->read = cmd->info.devaddr & 0x01;
> >   	switch(cmd->info.type) {
> >   	case SMU_I2C_TRANSFER_SIMPLE:
> > -		memset(&cmd->info.sublen, 0, 4);
> > +		cmd->info.sublen = 0;
> > +		memset(&cmd->info.subaddr, 0, 3);
> 
> subaddr[] is a table, should the & be avoided ?

It results in the same thing, but it's better form to not have the &; I
will fix this.

> And while at it, why not use sizeof(subaddr) instead of 3 ?

Agreed. :)

Thanks!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 05/63] stddef: Introduce struct_group() helper macro
  2021-08-18  6:04 ` [PATCH v2 05/63] stddef: Introduce struct_group() helper macro Kees Cook
@ 2021-08-18 22:35   ` Dan Williams
  0 siblings, 0 replies; 116+ messages in thread
From: Dan Williams @ 2021-08-18 22:35 UTC (permalink / raw)
  To: Kees Cook
  Cc: Linux Kernel Mailing List, Keith Packard, Gustavo A . R . Silva,
	Rasmus Villemoes, Daniel Vetter, Greg Kroah-Hartman,
	Andrew Morton, Linux Wireless List, Netdev,
	Maling list - DRI developers, linux-staging, linux-block,
	Linux Kbuild mailing list, clang-built-linux, linux-hardening

On Tue, Aug 17, 2021 at 11:06 PM Kees Cook <keescook@chromium.org> wrote:
>
> Kernel code has a regular need to describe groups of members within a
> structure usually when they need to be copied or initialized separately
> from the rest of the surrounding structure. The generally accepted design
> pattern in C is to use a named sub-struct:
>
>         struct foo {
>                 int one;
>                 struct {
>                         int two;
>                         int three, four;
>                 } thing;
>                 int five;
>         };
>
> This would allow for traditional references and sizing:
>
>         memcpy(&dst.thing, &src.thing, sizeof(dst.thing));
>
> However, doing this would mean that referencing struct members enclosed
> by such named structs would always require including the sub-struct name
> in identifiers:
>
>         do_something(dst.thing.three);
>
> This has tended to be quite inflexible, especially when such groupings
> need to be added to established code which causes huge naming churn.
> Three workarounds exist in the kernel for this problem, and each have
> other negative properties.
>
> To avoid the naming churn, there is a design pattern of adding macro
> aliases for the named struct:
>
>         #define f_three thing.three
>
> This ends up polluting the global namespace, and makes it difficult to
> search for identifiers.
>
> Another common work-around in kernel code avoids the pollution by avoiding
> the named struct entirely, instead identifying the group's boundaries using
> either a pair of empty anonymous structs of a pair of zero-element arrays:
>
>         struct foo {
>                 int one;
>                 struct { } start;
>                 int two;
>                 int three, four;
>                 struct { } finish;
>                 int five;
>         };
>
>         struct foo {
>                 int one;
>                 int start[0];
>                 int two;
>                 int three, four;
>                 int finish[0];
>                 int five;
>         };
>
> This allows code to avoid needing to use a sub-struct named for member
> references within the surrounding structure, but loses the benefits of
> being able to actually use such a struct, making it rather fragile. Using
> these requires open-coded calculation of sizes and offsets. The efforts
> made to avoid common mistakes include lots of comments, or adding various
> BUILD_BUG_ON()s. Such code is left with no way for the compiler to reason
> about the boundaries (e.g. the "start" object looks like it's 0 bytes
> in length), making bounds checking depend on open-coded calculations:
>
>         if (length > offsetof(struct foo, finish) -
>                      offsetof(struct foo, start))
>                 return -EINVAL;
>         memcpy(&dst.start, &src.start, offsetof(struct foo, finish) -
>                                        offsetof(struct foo, start));
>
> However, the vast majority of places in the kernel that operate on
> groups of members do so without any identification of the grouping,
> relying either on comments or implicit knowledge of the struct contents,
> which is even harder for the compiler to reason about, and results in
> even more fragile manual sizing, usually depending on member locations
> outside of the region (e.g. to copy "two" and "three", use the start of
> "four" to find the size):
>
>         BUILD_BUG_ON((offsetof(struct foo, four) <
>                       offsetof(struct foo, two)) ||
>                      (offsetof(struct foo, four) <
>                       offsetof(struct foo, three));
>         if (length > offsetof(struct foo, four) -
>                      offsetof(struct foo, two))
>                 return -EINVAL;
>         memcpy(&dst.two, &src.two, length);
>
> In order to have a regular programmatic way to describe a struct
> region that can be used for references and sizing, can be examined for
> bounds checking, avoids forcing the use of intermediate identifiers,
> and avoids polluting the global namespace, introduce the struct_group()
> macro. This macro wraps the member declarations to create an anonymous
> union of an anonymous struct (no intermediate name) and a named struct
> (for references and sizing):
>
>         struct foo {
>                 int one;
>                 struct_group(thing,
>                         int two;
>                         int three, four;
>                 );
>                 int five;
>         };
>
>         if (length > sizeof(src.thing))
>                 return -EINVAL;
>         memcpy(&dst.thing, &src.thing, length);
>         do_something(dst.three);
>
> There are some rare cases where the resulting struct_group() needs
> attributes added, so struct_group_attr() is also introduced to allow
> for specifying struct attributes (e.g. __align(x) or __packed).
> Additionally, there are places where such declarations would like to
> have the struct be typed, so struct_group_typed() is added.
>
> Given there is a need for a handful of UAPI uses too, the underlying
> __struct_group() macro has been defined in UAPI so it can be used there
> too.
>
> Co-developed-by: Keith Packard <keithp@keithp.com>
> Signed-off-by: Keith Packard <keithp@keithp.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> Link: https://lore.kernel.org/lkml/20210728023217.GC35706@embeddedor
> Enhanced-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> Link: https://lore.kernel.org/lkml/41183a98-bdb9-4ad6-7eab-5a7292a6df84@rasmusvillemoes.dk
> Enhanced-by: Dan Williams <dan.j.williams@intel.com>

Acked-by: Dan Williams <dan.j.williams@intel.com>

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 06/63] cxl/core: Replace unions with struct_group()
  2021-08-18  6:04 ` [PATCH v2 06/63] cxl/core: Replace unions with struct_group() Kees Cook
@ 2021-08-18 22:36   ` Dan Williams
  0 siblings, 0 replies; 116+ messages in thread
From: Dan Williams @ 2021-08-18 22:36 UTC (permalink / raw)
  To: Kees Cook
  Cc: Linux Kernel Mailing List, Alison Schofield, Vishal Verma,
	Ira Weiny, Ben Widawsky, linux-cxl, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, Linux Wireless List, Netdev,
	Maling list - DRI developers, linux-staging, linux-block,
	Linux Kbuild mailing list, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Tue, Aug 17, 2021 at 11:06 PM Kees Cook <keescook@chromium.org> wrote:
>
> Use the newly introduced struct_group_typed() macro to clean up the
> declaration of struct cxl_regs.
>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Ben Widawsky <ben.widawsky@intel.com>
> Cc: linux-cxl@vger.kernel.org
> Suggested-by: Dan Williams <dan.j.williams@intel.com>

Looks good and tests ok here:

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache
  2021-08-18 16:23     ` Kees Cook
@ 2021-08-18 22:53       ` Sean Christopherson
  2021-08-18 23:06         ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Sean Christopherson @ 2021-08-18 22:53 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Paolo Bonzini, Vitaly Kuznetsov, Wanpeng Li,
	Jim Mattson, Joerg Roedel, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, kvm, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021, Kees Cook wrote:
> On Wed, Aug 18, 2021 at 03:11:28PM +0000, Sean Christopherson wrote:
> > From dbdca1f4cd01fee418c252e54c360d518b2b1ad6 Mon Sep 17 00:00:00 2001
> > From: Sean Christopherson <seanjc@google.com>
> > Date: Wed, 18 Aug 2021 08:03:08 -0700
> > Subject: [PATCH] KVM: x86: Replace memset() "optimization" with normal
> >  per-field writes
> > 
> > Explicitly zero select fields in the emulator's decode cache instead of
> > zeroing the fields via a gross memset() that spans six fields.  gcc and
> > clang are both clever enough to batch the first five fields into a single
> > quadword MOV, i.e. memset() and individually zeroing generate identical
> > code.
> > 
> > Removing the wart also prepares KVM for FORTIFY_SOURCE performing
> > compile-time and run-time field bounds checking for memset().
> > 
> > No functional change intended.
> > 
> > Reported-by: Kees Cook <keescook@chromium.org>
> > Signed-off-by: Sean Christopherson <seanjc@google.com>
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> 
> Do you want me to take this patch into my tree, or do you want to carry
> it for KVM directly?

That's a Paolo question :-)

What's the expected timeframe for landing stricter bounds checking?  If it's
5.16 or later, the easiest thing would be to squeak this into 5.15.

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache
  2021-08-18 22:53       ` Sean Christopherson
@ 2021-08-18 23:06         ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-18 23:06 UTC (permalink / raw)
  To: Sean Christopherson
  Cc: linux-kernel, Paolo Bonzini, Vitaly Kuznetsov, Wanpeng Li,
	Jim Mattson, Joerg Roedel, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, kvm, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 10:53:58PM +0000, Sean Christopherson wrote:
> On Wed, Aug 18, 2021, Kees Cook wrote:
> > On Wed, Aug 18, 2021 at 03:11:28PM +0000, Sean Christopherson wrote:
> > > From dbdca1f4cd01fee418c252e54c360d518b2b1ad6 Mon Sep 17 00:00:00 2001
> > > From: Sean Christopherson <seanjc@google.com>
> > > Date: Wed, 18 Aug 2021 08:03:08 -0700
> > > Subject: [PATCH] KVM: x86: Replace memset() "optimization" with normal
> > >  per-field writes
> > > 
> > > Explicitly zero select fields in the emulator's decode cache instead of
> > > zeroing the fields via a gross memset() that spans six fields.  gcc and
> > > clang are both clever enough to batch the first five fields into a single
> > > quadword MOV, i.e. memset() and individually zeroing generate identical
> > > code.
> > > 
> > > Removing the wart also prepares KVM for FORTIFY_SOURCE performing
> > > compile-time and run-time field bounds checking for memset().
> > > 
> > > No functional change intended.
> > > 
> > > Reported-by: Kees Cook <keescook@chromium.org>
> > > Signed-off-by: Sean Christopherson <seanjc@google.com>
> > 
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > 
> > Do you want me to take this patch into my tree, or do you want to carry
> > it for KVM directly?
> 
> That's a Paolo question :-)
> 
> What's the expected timeframe for landing stricter bounds checking?  If it's
> 5.16 or later, the easiest thing would be to squeak this into 5.15.

I'm hoping to land all the "compile time" stuff for 5.15, but
realistically, some portions may not get there. I'll just carry this
patch for now and if we need to swap trees we can do that. :)

Thanks!

-Kees

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 18/63] drm/amd/pm: Use struct_group() for memcpy() region
  2021-08-18 11:42   ` Lazar, Lijo
@ 2021-08-18 23:59     ` Kees Cook
  2021-08-19  5:03       ` Lazar, Lijo
  0 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-18 23:59 UTC (permalink / raw)
  To: Lazar, Lijo
  Cc: linux-kernel, Christian König, Pan, Xinhui, David Airlie,
	Daniel Vetter, Hawking Zhang, Feifei Xu, Likun Gao, Jiawei Gu,
	Evan Quan, amd-gfx, dri-devel, Alex Deucher, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 05:12:28PM +0530, Lazar, Lijo wrote:
> 
> On 8/18/2021 11:34 AM, Kees Cook wrote:
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memcpy(), memmove(), and memset(), avoid
> > intentionally writing across neighboring fields.
> > 
> > Use struct_group() in structs:
> > 	struct atom_smc_dpm_info_v4_5
> > 	struct atom_smc_dpm_info_v4_6
> > 	struct atom_smc_dpm_info_v4_7
> > 	struct atom_smc_dpm_info_v4_10
> > 	PPTable_t
> > so the grouped members can be referenced together. This will allow
> > memcpy() and sizeof() to more easily reason about sizes, improve
> > readability, and avoid future warnings about writing beyond the end of
> > the first member.
> > 
> > "pahole" shows no size nor member offset changes to any structs.
> > "objdump -d" shows no object code changes.
> > 
> > Cc: "Christian König" <christian.koenig@amd.com>
> > Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> > Cc: David Airlie <airlied@linux.ie>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> > Cc: Feifei Xu <Feifei.Xu@amd.com>
> > Cc: Lijo Lazar <lijo.lazar@amd.com>
> > Cc: Likun Gao <Likun.Gao@amd.com>
> > Cc: Jiawei Gu <Jiawei.Gu@amd.com>
> > Cc: Evan Quan <evan.quan@amd.com>
> > Cc: amd-gfx@lists.freedesktop.org
> > Cc: dri-devel@lists.freedesktop.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > Acked-by: Alex Deucher <alexander.deucher@amd.com>
> > Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2FCADnq5_Npb8uYvd%2BR4UHgf-w8-cQj3JoODjviJR_Y9w9wqJ71mQ%40mail.gmail.com&amp;data=04%7C01%7Clijo.lazar%40amd.com%7C92b8d2f072f0444b9f8508d9620f6971%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637648640625729624%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=rKh5LUXCRUsorYM3kSpG2tkB%2Fczwl9I9EBnWBCtbg6Q%3D&amp;reserved=0
> > ---
> >   drivers/gpu/drm/amd/include/atomfirmware.h           |  9 ++++++++-
> >   .../gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h    |  3 ++-
> >   drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h  |  3 ++-
> >   .../gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h   |  3 ++-
> 
> Hi Kees,

Hi! Thanks for looking into this.

> The headers which define these structs are firmware/VBIOS interfaces and are
> picked directly from those components. There are difficulties in grouping
> them to structs at the original source as that involves other component
> changes.

So, can you help me understand this a bit more? It sounds like these are
generated headers, yes? I'd like to understand your constraints and
weight them against various benefits that could be achieved here.

The groupings I made do appear to be roughly documented already,
for example:

   struct   atom_common_table_header  table_header;
     // SECTION: BOARD PARAMETERS
+  struct_group(dpm_info,

Something emitted the "BOARD PARAMETERS" section heading as a comment,
so it likely also would know where it ends, yes? The good news here is
that for the dpm_info groups, they all end at the end of the existing
structs, see:
	struct atom_smc_dpm_info_v4_5
	struct atom_smc_dpm_info_v4_6
	struct atom_smc_dpm_info_v4_7
	struct atom_smc_dpm_info_v4_10

The matching regions in the PPTable_t structs are similarly marked with a
"BOARD PARAMETERS" section heading comment:

--- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
+++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
@@ -643,6 +643,7 @@ typedef struct {
   // SECTION: BOARD PARAMETERS
 
   // SVI2 Board Parameters
+  struct_group(v4_6,
   uint16_t     MaxVoltageStepGfx; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
   uint16_t     MaxVoltageStepSoc; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
 
@@ -728,10 +729,10 @@ typedef struct {
   uint32_t     BoardVoltageCoeffB;    // decode by /1000
 
   uint32_t     BoardReserved[7];
+  );
 
   // Padding for MMHUB - do not modify this
   uint32_t     MmHubPadding[8]; // SMU internal use
-
 } PPTable_t;

Where they end seems known as well (the padding switches from a "Board"
to "MmHub" prefix at exactly the matching size).

So, given that these regions are already known by the export tool, how
about just updating the export tool to emit a struct there? I imagine
the problem with this would be the identifier churn needed, but that's
entirely mechanical.

However, I'm curious about another aspect of these regions: they are,
by definition, the same. Why isn't there a single struct describing
them already, given the existing redundancy? For example, look at the
member names: maxvoltagestepgfx vs MaxVoltageStepGfx. Why aren't these
the same? And then why aren't they described separately?

Fixing that would cut down on the redundancy here, and in the renaming,
you can fix the identifiers as well. It should be straight forward to
write a Coccinelle script to do this renaming for you after extracting
the structure.

> The driver_if_* files updates are frequent and it is error prone to manually
> group them each time we pick them for any update.

Why are these structs updated? It looks like they're specifically
versioned, and aren't expected to change (i.e. v4.5, v4.6, v4.10, etc).

> Our usage of memcpy in this way is restricted only to a very few places.

True, there's 1 per PPTable_t duplication. With a proper struct, you
wouldn't even need a memcpy().

Instead of the existing:
               memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
                       sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));

or my proposed:
               memcpy(&smc_pptable->v4, &smc_dpm_table_v4_7->dpm_info,
                      sizeof(smc_dpm_table_v4_7->dpm_info));

you could just have:
		smc_pptable->v4 = smc_dpm_table_v4_7->dpm_info;

since they'd be explicitly the same type.

That looks like a much cleaner solution to this. It greatly improves
readability, reduces the redundancy in the headers, and should be a
simple mechanical refactoring.

Oh my, I just noticed append_vbios_pptable() in
drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega12_processpptables.c
which does an open-coded assignment of the entire PPTable_t, including
padding, and, apparently, the i2c address twice:

        ppsmc_pptable->Vr2_I2C_address = smc_dpm_table.Vr2_I2C_address;

        ppsmc_pptable->Vr2_I2C_address = smc_dpm_table.Vr2_I2C_address;

> As another option - is it possible to have a helper function/macro like
> memcpy_fortify() which takes the extra arguments and does the extra compile
> time checks? We will use the helper whenever we have such kind of usage.

I'd rather avoid special cases just for this, especially when the code
here is already doing a couple things we try to avoid in the rest of
the kernel (i.e. open coded redundant struct contents, etc).

If something mechanically produced append_vbios_pptable() above, I bet
we can get rid of the memcpy()s entirely and save a lot of code doing a
member-to-member assignment.

What do you think?

-Kees

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 18/63] drm/amd/pm: Use struct_group() for memcpy() region
  2021-08-18 23:59     ` Kees Cook
@ 2021-08-19  5:03       ` Lazar, Lijo
  2021-08-19 19:58         ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Lazar, Lijo @ 2021-08-19  5:03 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Christian König, Pan, Xinhui, David Airlie,
	Daniel Vetter, Hawking Zhang, Feifei Xu, Likun Gao, Jiawei Gu,
	Evan Quan, amd-gfx, dri-devel, Alex Deucher, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening



On 8/19/2021 5:29 AM, Kees Cook wrote:
> On Wed, Aug 18, 2021 at 05:12:28PM +0530, Lazar, Lijo wrote:
>>
>> On 8/18/2021 11:34 AM, Kees Cook wrote:
>>> In preparation for FORTIFY_SOURCE performing compile-time and run-time
>>> field bounds checking for memcpy(), memmove(), and memset(), avoid
>>> intentionally writing across neighboring fields.
>>>
>>> Use struct_group() in structs:
>>> 	struct atom_smc_dpm_info_v4_5
>>> 	struct atom_smc_dpm_info_v4_6
>>> 	struct atom_smc_dpm_info_v4_7
>>> 	struct atom_smc_dpm_info_v4_10
>>> 	PPTable_t
>>> so the grouped members can be referenced together. This will allow
>>> memcpy() and sizeof() to more easily reason about sizes, improve
>>> readability, and avoid future warnings about writing beyond the end of
>>> the first member.
>>>
>>> "pahole" shows no size nor member offset changes to any structs.
>>> "objdump -d" shows no object code changes.
>>>
>>> Cc: "Christian König" <christian.koenig@amd.com>
>>> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
>>> Cc: David Airlie <airlied@linux.ie>
>>> Cc: Daniel Vetter <daniel@ffwll.ch>
>>> Cc: Hawking Zhang <Hawking.Zhang@amd.com>
>>> Cc: Feifei Xu <Feifei.Xu@amd.com>
>>> Cc: Lijo Lazar <lijo.lazar@amd.com>
>>> Cc: Likun Gao <Likun.Gao@amd.com>
>>> Cc: Jiawei Gu <Jiawei.Gu@amd.com>
>>> Cc: Evan Quan <evan.quan@amd.com>
>>> Cc: amd-gfx@lists.freedesktop.org
>>> Cc: dri-devel@lists.freedesktop.org
>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>> Acked-by: Alex Deucher <alexander.deucher@amd.com>
>>> Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2FCADnq5_Npb8uYvd%2BR4UHgf-w8-cQj3JoODjviJR_Y9w9wqJ71mQ%40mail.gmail.com&amp;data=04%7C01%7Clijo.lazar%40amd.com%7C3861f20094074bf7328808d962a433f2%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637649279701053991%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=386LcfJJGfQfHsXBuK17LMqxJ2nFtGoj%2FUjoN2ZtJd0%3D&amp;reserved=0
>>> ---
>>>    drivers/gpu/drm/amd/include/atomfirmware.h           |  9 ++++++++-
>>>    .../gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h    |  3 ++-
>>>    drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h  |  3 ++-
>>>    .../gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h   |  3 ++-
>>
>> Hi Kees,
> 
> Hi! Thanks for looking into this.
> 
>> The headers which define these structs are firmware/VBIOS interfaces and are
>> picked directly from those components. There are difficulties in grouping
>> them to structs at the original source as that involves other component
>> changes.
> 
> So, can you help me understand this a bit more? It sounds like these are
> generated headers, yes? I'd like to understand your constraints and
> weight them against various benefits that could be achieved here.
> 
> The groupings I made do appear to be roughly documented already,
> for example:
> 
>     struct   atom_common_table_header  table_header;
>       // SECTION: BOARD PARAMETERS
> +  struct_group(dpm_info,
> 
> Something emitted the "BOARD PARAMETERS" section heading as a comment,
> so it likely also would know where it ends, yes? The good news here is
> that for the dpm_info groups, they all end at the end of the existing
> structs, see:
> 	struct atom_smc_dpm_info_v4_5
> 	struct atom_smc_dpm_info_v4_6
> 	struct atom_smc_dpm_info_v4_7
> 	struct atom_smc_dpm_info_v4_10
> 
> The matching regions in the PPTable_t structs are similarly marked with a
> "BOARD PARAMETERS" section heading comment:
> 
> --- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> @@ -643,6 +643,7 @@ typedef struct {
>     // SECTION: BOARD PARAMETERS
>   
>     // SVI2 Board Parameters
> +  struct_group(v4_6,
>     uint16_t     MaxVoltageStepGfx; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
>     uint16_t     MaxVoltageStepSoc; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
>   
> @@ -728,10 +729,10 @@ typedef struct {
>     uint32_t     BoardVoltageCoeffB;    // decode by /1000
>   
>     uint32_t     BoardReserved[7];
> +  );
>   
>     // Padding for MMHUB - do not modify this
>     uint32_t     MmHubPadding[8]; // SMU internal use
> -
>   } PPTable_t;
> 
> Where they end seems known as well (the padding switches from a "Board"
> to "MmHub" prefix at exactly the matching size).
> 
> So, given that these regions are already known by the export tool, how
> about just updating the export tool to emit a struct there? I imagine
> the problem with this would be the identifier churn needed, but that's
> entirely mechanical.
> 
> However, I'm curious about another aspect of these regions: they are,
> by definition, the same. Why isn't there a single struct describing
> them already, given the existing redundancy? For example, look at the
> member names: maxvoltagestepgfx vs MaxVoltageStepGfx. Why aren't these
> the same? And then why aren't they described separately?
> 
> Fixing that would cut down on the redundancy here, and in the renaming,
> you can fix the identifiers as well. It should be straight forward to
> write a Coccinelle script to do this renaming for you after extracting
> the structure.
> 
>> The driver_if_* files updates are frequent and it is error prone to manually
>> group them each time we pick them for any update.
> 
> Why are these structs updated? It looks like they're specifically
> versioned, and aren't expected to change (i.e. v4.5, v4.6, v4.10, etc).
> 
>> Our usage of memcpy in this way is restricted only to a very few places.
> 
> True, there's 1 per PPTable_t duplication. With a proper struct, you
> wouldn't even need a memcpy().
> 
> Instead of the existing:
>                 memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
>                         sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));
> 
> or my proposed:
>                 memcpy(&smc_pptable->v4, &smc_dpm_table_v4_7->dpm_info,
>                        sizeof(smc_dpm_table_v4_7->dpm_info));
> 
> you could just have:
> 		smc_pptable->v4 = smc_dpm_table_v4_7->dpm_info;
> 
> since they'd be explicitly the same type.
> 
> That looks like a much cleaner solution to this. It greatly improves
> readability, reduces the redundancy in the headers, and should be a
> simple mechanical refactoring.
> 
> Oh my, I just noticed append_vbios_pptable() in
> drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega12_processpptables.c
> which does an open-coded assignment of the entire PPTable_t, including
> padding, and, apparently, the i2c address twice:
> 
>          ppsmc_pptable->Vr2_I2C_address = smc_dpm_table.Vr2_I2C_address;
> 
>          ppsmc_pptable->Vr2_I2C_address = smc_dpm_table.Vr2_I2C_address;
> 
>> As another option - is it possible to have a helper function/macro like
>> memcpy_fortify() which takes the extra arguments and does the extra compile
>> time checks? We will use the helper whenever we have such kind of usage.
> 
> I'd rather avoid special cases just for this, especially when the code
> here is already doing a couple things we try to avoid in the rest of
> the kernel (i.e. open coded redundant struct contents, etc).
> 
> If something mechanically produced append_vbios_pptable() above, I bet
> we can get rid of the memcpy()s entirely and save a lot of code doing a
> member-to-member assignment.
> 
> What do you think?
> 

Hi Kees,

Will give a background on why there are multiple headers and why it's 
structured this way. That may help to better understand this arrangement.

This code is part of driver for AMD GPUs. These GPUs get to the 
consumers through multiple channels - AMD designs a few boards with 
those, there are add-in-board partners like ASRock, Sapphire etc. who 
take these ASICs and design their own boards, and others like OEM 
vendors who have their own design for boards in their laptops.

As you have noticed, this particular section in the structure carries 
information categorized as 'BOARD PARAMETERS'. Since there are multiple 
vendors designing their own boards, this gives the option to customize 
the parameters based on their board design.

There are a few components in AMD GPUs which are interested in these 
board parameters main ones being - Video BIOS (VBIOS) and power 
management firmware (PMFW). There needs to be a single source where a 
vendor can input the information and that is decided as VBIOS. VBIOS 
carries different data tables which carry other information also (some 
of which are used by driver), so this information is added as a separate 
data table in VBIOS. A board vendor can customize the VBIOS build with 
this information.

The data tables (and some other interfaces with driver) carried by VBIOS 
are published in this header - drivers/gpu/drm/amd/include/atomfirmware.h

There are multiple families of AMD GPUs like Navi10, Arcturus, Aldebaran 
etc. and the board specific details change with different families of 
GPUs. However, VBIOS team publishes a common header file for these GPUs 
and any difference in data tables (between GPU families) is maintained 
through a versioning scheme. Thus there are different tables like 
atom_smc_dpm_info_v4_5, atom_smc_dpm_info_v4_6 etc. which are relevant 
for a particular family of GPUs.

With newer VBIOS versions and new GPU families, there could be changes 
in the structs defined in atomfirmware.h and we pick the header accordingly.
	
As mentioned earlier, one other user of the board specific information 
is power management firmware (PMFW). PMFW design is isolated from the 
actual source of board information. In addition to board specific 
information, PMFW needs some other info as well and driver is the one 
responsible for passing this info to the firmware. PMFW gives an 
interface header to driver providing the different struct formats which 
are used in driver<->PMFW interactions. Unlike VBIOS, these interface 
headers are defined per family of ASICs and those are 
smu11_driver_if_arcturus.h, smu11_driver_if_* etc. (in short driver_if_* 
files). Like VBIOS,  with newer firmware versions, there could be 
changes in the different structs defined in these headers and we pick 
them accordingly.

Driver acts the intermediary between actual source of board information 
(VBIOS) and PMFW. So what is being done here is driver picks the board 
information from VBIOS table, strips the VBIOS table header and passes 
it as part of PPTable_t which defines all the information that is needed 
by PMFW from driver for enabling dynamic power management.

In summary, these headers are not generated and not owned by driver. 
They define the interfaces of two different components with driver, and 
are consumed by those components themselves. A simple change to group 
the information as a separate structure involves changes in multiple 
components like VBIOS, PMFW, software used to build VBIOS, Windows 
driver etc.

In all practical cases, this code is harmless as these structs (in both 
headers) are well defined for a specific family of GPUs. There is always 
a reserve field defined with some extra bytes so that the size is not 
affected if at all new fields need to be added.

The patch now makes us to modify the headers for Linux through 
script/manually whenever we pick them, and TBH that strips off the 
coherency with the original source. The other option is field by field 
copy. Now we use memcpy as a safe bet so that a new field added later 
taking some reserve space is not missed even if we miss a header update.

Thanks,
Lijo


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-18  6:05 ` [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr Kees Cook
@ 2021-08-19 12:27   ` Jason Gunthorpe
  2021-08-19 16:19     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Jason Gunthorpe @ 2021-08-19 12:27 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Leon Romanovsky, Doug Ledford, linux-rdma,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Tue, Aug 17, 2021 at 11:05:26PM -0700, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Add struct_group() to mark region of struct mlx5_ib_mr that should be
> initialized to zero.
> 
> Cc: Leon Romanovsky <leon@kernel.org>
> Cc: Doug Ledford <dledford@redhat.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: linux-rdma@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> index bf20a388eabe..f63bf204a7a1 100644
> --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
> +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> @@ -644,6 +644,7 @@ struct mlx5_ib_mr {
>  	struct ib_umem *umem;
>  
>  	/* This is zero'd when the MR is allocated */
> +	struct_group(cleared,
>  	union {
>  		/* Used only while the MR is in the cache */
>  		struct {
> @@ -691,12 +692,13 @@ struct mlx5_ib_mr {
>  			bool is_odp_implicit;
>  		};
>  	};
> +	);
>  };
>  
>  /* Zero the fields in the mr that are variant depending on usage */
>  static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
>  {
> -	memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
> +	memset(&mr->cleared, 0, sizeof(mr->cleared));
>  }

Why not use the memset_after(mr->umem) here?

Jason

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors
  2021-08-18  6:05 ` [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors Kees Cook
@ 2021-08-19 13:19   ` Kalle Valo
  2021-08-19 16:25     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Kalle Valo @ 2021-08-19 13:19 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, David S. Miller, Jakub Kicinski, ath11k,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Kees Cook <keescook@chromium.org> writes:

> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
>
> Use memset_startat() so memset() doesn't get confused about writing
> beyond the destination member that is intended to be the starting point
> of zeroing through the end of the struct. Additionally split up a later
> field-spanning memset() so that memset() can reason about the size.
>
> Cc: Kalle Valo <kvalo@codeaurora.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: ath11k@lists.infradead.org
> Cc: linux-wireless@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

To avoid conflicts I prefer taking this via my ath tree.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-19 12:27   ` Jason Gunthorpe
@ 2021-08-19 16:19     ` Kees Cook
  2021-08-19 16:47       ` Jason Gunthorpe
  0 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-19 16:19 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: linux-kernel, Leon Romanovsky, Doug Ledford, linux-rdma,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Thu, Aug 19, 2021 at 09:27:16AM -0300, Jason Gunthorpe wrote:
> On Tue, Aug 17, 2021 at 11:05:26PM -0700, Kees Cook wrote:
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memset(), avoid intentionally writing across
> > neighboring fields.
> > 
> > Add struct_group() to mark region of struct mlx5_ib_mr that should be
> > initialized to zero.
> > 
> > Cc: Leon Romanovsky <leon@kernel.org>
> > Cc: Doug Ledford <dledford@redhat.com>
> > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > Cc: linux-rdma@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > index bf20a388eabe..f63bf204a7a1 100644
> > --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > @@ -644,6 +644,7 @@ struct mlx5_ib_mr {
> >  	struct ib_umem *umem;
> >  
> >  	/* This is zero'd when the MR is allocated */
> > +	struct_group(cleared,
> >  	union {
> >  		/* Used only while the MR is in the cache */
> >  		struct {
> > @@ -691,12 +692,13 @@ struct mlx5_ib_mr {
> >  			bool is_odp_implicit;
> >  		};
> >  	};
> > +	);
> >  };
> >  
> >  /* Zero the fields in the mr that are variant depending on usage */
> >  static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
> >  {
> > -	memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
> > +	memset(&mr->cleared, 0, sizeof(mr->cleared));
> >  }
> 
> Why not use the memset_after(mr->umem) here?

I can certainly do that instead. In this series I've tended to opt
for groupings so the position of future struct member additions are
explicitly chosen. (i.e. reducing the chance that a zeroing of the new
member be a surprise.)

-Kees

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors
  2021-08-19 13:19   ` Kalle Valo
@ 2021-08-19 16:25     ` Kees Cook
  2021-08-21 10:17       ` Kalle Valo
  0 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-19 16:25 UTC (permalink / raw)
  To: Kalle Valo
  Cc: linux-kernel, David S. Miller, Jakub Kicinski, ath11k,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Thu, Aug 19, 2021 at 04:19:37PM +0300, Kalle Valo wrote:
> Kees Cook <keescook@chromium.org> writes:
> 
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memset(), avoid intentionally writing across
> > neighboring fields.
> >
> > Use memset_startat() so memset() doesn't get confused about writing
> > beyond the destination member that is intended to be the starting point
> > of zeroing through the end of the struct. Additionally split up a later
> > field-spanning memset() so that memset() can reason about the size.
> >
> > Cc: Kalle Valo <kvalo@codeaurora.org>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: ath11k@lists.infradead.org
> > Cc: linux-wireless@vger.kernel.org
> > Cc: netdev@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> 
> To avoid conflicts I prefer taking this via my ath tree.

The memset helpers are introduced as part of this series, so that makes
things more difficult. Do you want me to create a branch with the
helpers that you can merge?

-Kees

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-19 16:19     ` Kees Cook
@ 2021-08-19 16:47       ` Jason Gunthorpe
  2021-08-19 18:14         ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Jason Gunthorpe @ 2021-08-19 16:47 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Leon Romanovsky, Doug Ledford, linux-rdma,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Thu, Aug 19, 2021 at 09:19:08AM -0700, Kees Cook wrote:
> On Thu, Aug 19, 2021 at 09:27:16AM -0300, Jason Gunthorpe wrote:
> > On Tue, Aug 17, 2021 at 11:05:26PM -0700, Kees Cook wrote:
> > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > field bounds checking for memset(), avoid intentionally writing across
> > > neighboring fields.
> > > 
> > > Add struct_group() to mark region of struct mlx5_ib_mr that should be
> > > initialized to zero.
> > > 
> > > Cc: Leon Romanovsky <leon@kernel.org>
> > > Cc: Doug Ledford <dledford@redhat.com>
> > > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > > Cc: linux-rdma@vger.kernel.org
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > >  drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > > index bf20a388eabe..f63bf204a7a1 100644
> > > +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > > @@ -644,6 +644,7 @@ struct mlx5_ib_mr {
> > >  	struct ib_umem *umem;
> > >  
> > >  	/* This is zero'd when the MR is allocated */
> > > +	struct_group(cleared,
> > >  	union {
> > >  		/* Used only while the MR is in the cache */
> > >  		struct {
> > > @@ -691,12 +692,13 @@ struct mlx5_ib_mr {
> > >  			bool is_odp_implicit;
> > >  		};
> > >  	};
> > > +	);
> > >  };
> > >  
> > >  /* Zero the fields in the mr that are variant depending on usage */
> > >  static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
> > >  {
> > > -	memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
> > > +	memset(&mr->cleared, 0, sizeof(mr->cleared));
> > >  }
> > 
> > Why not use the memset_after(mr->umem) here?
> 
> I can certainly do that instead. In this series I've tended to opt
> for groupings so the position of future struct member additions are
> explicitly chosen. (i.e. reducing the chance that a zeroing of the new
> member be a surprise.)

I saw the earlier RDMA patches where using other memset techniques
though? Were there flex arrays or something that made groups infeasible?

Jason

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-19 16:47       ` Jason Gunthorpe
@ 2021-08-19 18:14         ` Kees Cook
  2021-08-20 12:34           ` Jason Gunthorpe
  0 siblings, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-19 18:14 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: linux-kernel, Leon Romanovsky, Doug Ledford, linux-rdma,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Thu, Aug 19, 2021 at 01:47:57PM -0300, Jason Gunthorpe wrote:
> On Thu, Aug 19, 2021 at 09:19:08AM -0700, Kees Cook wrote:
> > On Thu, Aug 19, 2021 at 09:27:16AM -0300, Jason Gunthorpe wrote:
> > > On Tue, Aug 17, 2021 at 11:05:26PM -0700, Kees Cook wrote:
> > > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > > field bounds checking for memset(), avoid intentionally writing across
> > > > neighboring fields.
> > > > 
> > > > Add struct_group() to mark region of struct mlx5_ib_mr that should be
> > > > initialized to zero.
> > > > 
> > > > Cc: Leon Romanovsky <leon@kernel.org>
> > > > Cc: Doug Ledford <dledford@redhat.com>
> > > > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > > > Cc: linux-rdma@vger.kernel.org
> > > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > >  drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
> > > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > > > index bf20a388eabe..f63bf204a7a1 100644
> > > > +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > > > @@ -644,6 +644,7 @@ struct mlx5_ib_mr {
> > > >  	struct ib_umem *umem;
> > > >  
> > > >  	/* This is zero'd when the MR is allocated */
> > > > +	struct_group(cleared,
> > > >  	union {
> > > >  		/* Used only while the MR is in the cache */
> > > >  		struct {
> > > > @@ -691,12 +692,13 @@ struct mlx5_ib_mr {
> > > >  			bool is_odp_implicit;
> > > >  		};
> > > >  	};
> > > > +	);
> > > >  };
> > > >  
> > > >  /* Zero the fields in the mr that are variant depending on usage */
> > > >  static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
> > > >  {
> > > > -	memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
> > > > +	memset(&mr->cleared, 0, sizeof(mr->cleared));
> > > >  }
> > > 
> > > Why not use the memset_after(mr->umem) here?
> > 
> > I can certainly do that instead. In this series I've tended to opt
> > for groupings so the position of future struct member additions are
> > explicitly chosen. (i.e. reducing the chance that a zeroing of the new
> > member be a surprise.)
> 
> I saw the earlier RDMA patches where using other memset techniques
> though? Were there flex arrays or something that made groups infeasible?

Which do you mean? When doing the conversions I tended to opt for
struct_group() since it provides more robust "intentionality". Strictly
speaking, the new memset helpers are doing field-spanning writes, but the
"clear to the end" pattern was so common it made sense to add the helpers,
as they're a bit less disruptive. It's totally up to you! :)

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 18/63] drm/amd/pm: Use struct_group() for memcpy() region
  2021-08-19  5:03       ` Lazar, Lijo
@ 2021-08-19 19:58         ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-19 19:58 UTC (permalink / raw)
  To: Lazar, Lijo
  Cc: linux-kernel, Christian König, Pan, Xinhui, David Airlie,
	Daniel Vetter, Hawking Zhang, Feifei Xu, Likun Gao, Jiawei Gu,
	Evan Quan, amd-gfx, dri-devel, Alex Deucher, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	linux-staging, linux-block, linux-kbuild, clang-built-linux,
	Rasmus Villemoes, linux-hardening

On Thu, Aug 19, 2021 at 10:33:43AM +0530, Lazar, Lijo wrote:
> On 8/19/2021 5:29 AM, Kees Cook wrote:
> > On Wed, Aug 18, 2021 at 05:12:28PM +0530, Lazar, Lijo wrote:
> > > 
> > > On 8/18/2021 11:34 AM, Kees Cook wrote:
> > > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > > field bounds checking for memcpy(), memmove(), and memset(), avoid
> > > > intentionally writing across neighboring fields.
> > > > 
> > > > Use struct_group() in structs:
> > > > 	struct atom_smc_dpm_info_v4_5
> > > > 	struct atom_smc_dpm_info_v4_6
> > > > 	struct atom_smc_dpm_info_v4_7
> > > > 	struct atom_smc_dpm_info_v4_10
> > > > 	PPTable_t
> > > > so the grouped members can be referenced together. This will allow
> > > > memcpy() and sizeof() to more easily reason about sizes, improve
> > > > readability, and avoid future warnings about writing beyond the end of
> > > > the first member.
> > > > 
> > > > "pahole" shows no size nor member offset changes to any structs.
> > > > "objdump -d" shows no object code changes.
> > > > 
> > > > Cc: "Christian König" <christian.koenig@amd.com>
> > > > Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> > > > Cc: David Airlie <airlied@linux.ie>
> > > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > > Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> > > > Cc: Feifei Xu <Feifei.Xu@amd.com>
> > > > Cc: Lijo Lazar <lijo.lazar@amd.com>
> > > > Cc: Likun Gao <Likun.Gao@amd.com>
> > > > Cc: Jiawei Gu <Jiawei.Gu@amd.com>
> > > > Cc: Evan Quan <evan.quan@amd.com>
> > > > Cc: amd-gfx@lists.freedesktop.org
> > > > Cc: dri-devel@lists.freedesktop.org
> > > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > > Acked-by: Alex Deucher <alexander.deucher@amd.com>
> > > > Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2FCADnq5_Npb8uYvd%2BR4UHgf-w8-cQj3JoODjviJR_Y9w9wqJ71mQ%40mail.gmail.com&amp;data=04%7C01%7Clijo.lazar%40amd.com%7C3861f20094074bf7328808d962a433f2%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637649279701053991%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=386LcfJJGfQfHsXBuK17LMqxJ2nFtGoj%2FUjoN2ZtJd0%3D&amp;reserved=0
> > > > ---
> > > >    drivers/gpu/drm/amd/include/atomfirmware.h           |  9 ++++++++-
> > > >    .../gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h    |  3 ++-
> > > >    drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h  |  3 ++-
> > > >    .../gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h   |  3 ++-
> > > 
> > > Hi Kees,
> > 
> > Hi! Thanks for looking into this.
> > 
> > > The headers which define these structs are firmware/VBIOS interfaces and are
> > > picked directly from those components. There are difficulties in grouping
> > > them to structs at the original source as that involves other component
> > > changes.
> > 
> > So, can you help me understand this a bit more? It sounds like these are
> > generated headers, yes? I'd like to understand your constraints and
> > weight them against various benefits that could be achieved here.
> > 
> > The groupings I made do appear to be roughly documented already,
> > for example:
> > 
> >     struct   atom_common_table_header  table_header;
> >       // SECTION: BOARD PARAMETERS
> > +  struct_group(dpm_info,
> > 
> > Something emitted the "BOARD PARAMETERS" section heading as a comment,
> > so it likely also would know where it ends, yes? The good news here is
> > that for the dpm_info groups, they all end at the end of the existing
> > structs, see:
> > 	struct atom_smc_dpm_info_v4_5
> > 	struct atom_smc_dpm_info_v4_6
> > 	struct atom_smc_dpm_info_v4_7
> > 	struct atom_smc_dpm_info_v4_10
> > 
> > The matching regions in the PPTable_t structs are similarly marked with a
> > "BOARD PARAMETERS" section heading comment:
> > 
> > --- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> > +++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> > @@ -643,6 +643,7 @@ typedef struct {
> >     // SECTION: BOARD PARAMETERS
> >     // SVI2 Board Parameters
> > +  struct_group(v4_6,
> >     uint16_t     MaxVoltageStepGfx; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
> >     uint16_t     MaxVoltageStepSoc; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
> > @@ -728,10 +729,10 @@ typedef struct {
> >     uint32_t     BoardVoltageCoeffB;    // decode by /1000
> >     uint32_t     BoardReserved[7];
> > +  );
> >     // Padding for MMHUB - do not modify this
> >     uint32_t     MmHubPadding[8]; // SMU internal use
> > -
> >   } PPTable_t;
> > 
> > Where they end seems known as well (the padding switches from a "Board"
> > to "MmHub" prefix at exactly the matching size).
> > 
> > So, given that these regions are already known by the export tool, how
> > about just updating the export tool to emit a struct there? I imagine
> > the problem with this would be the identifier churn needed, but that's
> > entirely mechanical.
> > 
> > However, I'm curious about another aspect of these regions: they are,
> > by definition, the same. Why isn't there a single struct describing
> > them already, given the existing redundancy? For example, look at the
> > member names: maxvoltagestepgfx vs MaxVoltageStepGfx. Why aren't these
> > the same? And then why aren't they described separately?
> > 
> > Fixing that would cut down on the redundancy here, and in the renaming,
> > you can fix the identifiers as well. It should be straight forward to
> > write a Coccinelle script to do this renaming for you after extracting
> > the structure.
> > 
> > > The driver_if_* files updates are frequent and it is error prone to manually
> > > group them each time we pick them for any update.
> > 
> > Why are these structs updated? It looks like they're specifically
> > versioned, and aren't expected to change (i.e. v4.5, v4.6, v4.10, etc).
> > 
> > > Our usage of memcpy in this way is restricted only to a very few places.
> > 
> > True, there's 1 per PPTable_t duplication. With a proper struct, you
> > wouldn't even need a memcpy().
> > 
> > Instead of the existing:
> >                 memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
> >                         sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));
> > 
> > or my proposed:
> >                 memcpy(&smc_pptable->v4, &smc_dpm_table_v4_7->dpm_info,
> >                        sizeof(smc_dpm_table_v4_7->dpm_info));
> > 
> > you could just have:
> > 		smc_pptable->v4 = smc_dpm_table_v4_7->dpm_info;
> > 
> > since they'd be explicitly the same type.
> > 
> > That looks like a much cleaner solution to this. It greatly improves
> > readability, reduces the redundancy in the headers, and should be a
> > simple mechanical refactoring.
> > 
> > Oh my, I just noticed append_vbios_pptable() in
> > drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega12_processpptables.c
> > which does an open-coded assignment of the entire PPTable_t, including
> > padding, and, apparently, the i2c address twice:
> > 
> >          ppsmc_pptable->Vr2_I2C_address = smc_dpm_table.Vr2_I2C_address;
> > 
> >          ppsmc_pptable->Vr2_I2C_address = smc_dpm_table.Vr2_I2C_address;
> > 
> > > As another option - is it possible to have a helper function/macro like
> > > memcpy_fortify() which takes the extra arguments and does the extra compile
> > > time checks? We will use the helper whenever we have such kind of usage.
> > 
> > I'd rather avoid special cases just for this, especially when the code
> > here is already doing a couple things we try to avoid in the rest of
> > the kernel (i.e. open coded redundant struct contents, etc).
> > 
> > If something mechanically produced append_vbios_pptable() above, I bet
> > we can get rid of the memcpy()s entirely and save a lot of code doing a
> > member-to-member assignment.
> > 
> > What do you think?
> > 
> 
> Hi Kees,
> 
> Will give a background on why there are multiple headers and why it's
> structured this way. That may help to better understand this arrangement.
> 
> This code is part of driver for AMD GPUs. These GPUs get to the consumers
> through multiple channels - AMD designs a few boards with those, there are
> add-in-board partners like ASRock, Sapphire etc. who take these ASICs and
> design their own boards, and others like OEM vendors who have their own
> design for boards in their laptops.
> 
> As you have noticed, this particular section in the structure carries
> information categorized as 'BOARD PARAMETERS'. Since there are multiple
> vendors designing their own boards, this gives the option to customize the
> parameters based on their board design.
> 
> There are a few components in AMD GPUs which are interested in these board
> parameters main ones being - Video BIOS (VBIOS) and power management
> firmware (PMFW). There needs to be a single source where a vendor can input
> the information and that is decided as VBIOS. VBIOS carries different data
> tables which carry other information also (some of which are used by
> driver), so this information is added as a separate data table in VBIOS. A
> board vendor can customize the VBIOS build with this information.
> 
> The data tables (and some other interfaces with driver) carried by VBIOS are
> published in this header - drivers/gpu/drm/amd/include/atomfirmware.h

I understand this to mean that this header is shared by other projects?

If that's true, what compilers are processing this header? (i.e. so I
can scope my suggestions to things that all the compilers will be able
to deal with.)

How are edits of this file managed "upstream" from the Linux kernel?

Why does it have strange indentations like this:

  uint8_t  ledpin0;
  uint8_t  ledpin1;
  uint8_t  ledpin2;
  uint8_t  padding8_4;

	uint8_t  pllgfxclkspreadenabled;
	uint8_t  pllgfxclkspreadpercent;
	uint16_t pllgfxclkspreadfreq;

  uint8_t uclkspreadenabled;
  uint8_t uclkspreadpercent;
  uint16_t uclkspreadfreq;


> There are multiple families of AMD GPUs like Navi10, Arcturus, Aldebaran
> etc. and the board specific details change with different families of GPUs.
> However, VBIOS team publishes a common header file for these GPUs and any
> difference in data tables (between GPU families) is maintained through a
> versioning scheme. Thus there are different tables like
> atom_smc_dpm_info_v4_5, atom_smc_dpm_info_v4_6 etc. which are relevant for a
> particular family of GPUs.
> 
> With newer VBIOS versions and new GPU families, there could be changes in
> the structs defined in atomfirmware.h and we pick the header accordingly.
> 
> As mentioned earlier, one other user of the board specific information is
> power management firmware (PMFW). PMFW design is isolated from the actual
> source of board information. In addition to board specific information, PMFW
> needs some other info as well and driver is the one responsible for passing
> this info to the firmware. PMFW gives an interface header to driver
> providing the different struct formats which are used in driver<->PMFW
> interactions. Unlike VBIOS, these interface headers are defined per family
> of ASICs and those are smu11_driver_if_arcturus.h, smu11_driver_if_* etc.
> (in short driver_if_* files). Like VBIOS,  with newer firmware versions,
> there could be changes in the different structs defined in these headers and
> we pick them accordingly.

Are these headers also shared between other projects?

What's needed to coordinate making these less redundant? (i.e. replacing
the "BOARD PARAMETERS" portion of PPTable_t with the associated
struct *_dpm_info_v* from atomfirmware.h?)

> Driver acts the intermediary between actual source of board information
> (VBIOS) and PMFW. So what is being done here is driver picks the board
> information from VBIOS table, strips the VBIOS table header and passes it as
> part of PPTable_t which defines all the information that is needed by PMFW
> from driver for enabling dynamic power management.
> 
> In summary, these headers are not generated and not owned by driver. They
> define the interfaces of two different components with driver, and are
> consumed by those components themselves. A simple change to group the
> information as a separate structure involves changes in multiple components
> like VBIOS, PMFW, software used to build VBIOS, Windows driver etc.
> 
> In all practical cases, this code is harmless as these structs (in both
> headers) are well defined for a specific family of GPUs. There is always a
> reserve field defined with some extra bytes so that the size is not affected
> if at all new fields need to be added.

It sounds like it's unlikely that the headers will be able to change? If
that's true, it seems like a good idea to mark those headers very
clearly at the top with details like you describe here. Maybe something
like:

/*
 * This header file is shared between VBIOS, Windows drivers, and Linux
 * drivers. Any changes need to be well justified and coordinated with
 * email@address...
 */

And in looking through these, I notice there's a typo in the Description:

    header file of general definitions for OS nd pre-OS video drivers

nd -> and

> The patch now makes us to modify the headers for Linux through
> script/manually whenever we pick them, and TBH that strips off the coherency
> with the original source. The other option is field by field copy. Now we
> use memcpy as a safe bet so that a new field added later taking some reserve
> space is not missed even if we miss a header update.

How does this look as a work-around for now:


diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 96e895d6be35..4605934a4fb7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1446,4 +1446,29 @@ static inline int amdgpu_in_reset(struct amdgpu_device *adev)
 {
 	return atomic_read(&adev->in_gpu_reset);
 }
+
+/**
+ * memcpy_trailing - Copy the end of one structure into the middle of another
+ *
+ * @dst: Pointer to destination struct
+ * @first_dst_member: The member name in @dst where the overwrite begins
+ * @last_dst_member: The member name in @dst where the overwrite ends after
+ * @src: Pointer to the source struct
+ * @first_src_member: The member name in @src where the copy begins
+ *
+ */
+#define memcpy_trailing(dst, first_dst_member, last_dst_member,		   \
+		        src, first_src_member)				   \
+({									   \
+	size_t __src_offset = offsetof(typeof(*(src)), first_src_member);  \
+	size_t __src_size = sizeof(*(src)) - __src_offset;		   \
+	size_t __dst_offset = offsetof(typeof(*(dst)), first_dst_member);  \
+	size_t __dst_size = offsetofend(typeof(*(dst)), last_dst_member) - \
+			    __dst_offset;				   \
+	BUILD_BUG_ON(__src_size != __dst_size);				   \
+	__builtin_memcpy((u8 *)(dst) + __dst_offset,			   \
+			 (u8 *)(src) + __src_offset,			   \
+			 __dst_size);					   \
+})
+
 #endif
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
index 8ab58781ae13..1918e6232319 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
@@ -465,10 +465,8 @@ static int arcturus_append_powerplay_table(struct smu_context *smu)
 
 	if ((smc_dpm_table->table_header.format_revision == 4) &&
 	    (smc_dpm_table->table_header.content_revision == 6))
-		memcpy(&smc_pptable->MaxVoltageStepGfx,
-		       &smc_dpm_table->maxvoltagestepgfx,
-		       sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_6, maxvoltagestepgfx));
-
+		memcpy_trailing(smc_pptable, MaxVoltageStepGfx, BoardReserved,
+				smc_dpm_table, maxvoltagestepgfx);
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
index 2e5d3669652b..b738042e064d 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
@@ -431,16 +431,16 @@ static int navi10_append_powerplay_table(struct smu_context *smu)
 
 	switch (smc_dpm_table->table_header.content_revision) {
 	case 5: /* nv10 and nv14 */
-		memcpy(smc_pptable->I2cControllers, smc_dpm_table->I2cControllers,
-			sizeof(*smc_dpm_table) - sizeof(smc_dpm_table->table_header));
+		memcpy_trailing(smc_pptable, I2cControllers, BoardReserved,
+				smc_dpm_table, I2cControllers);
 		break;
 	case 7: /* nv12 */
 		ret = amdgpu_atombios_get_data_table(adev, index, NULL, NULL, NULL,
 					      (uint8_t **)&smc_dpm_table_v4_7);
 		if (ret)
 			return ret;
-		memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
-			sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));
+		memcpy_trailing(smc_pptable, I2cControllers, BoardReserved,
+				smc_dpm_table_v4_7, I2cControllers);
 		break;
 	default:
 		dev_err(smu->adev->dev, "smc_dpm_info with unsupported content revision %d!\n",
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
index c8eefacfdd37..a6fd7ee314a9 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
@@ -409,9 +409,8 @@ static int aldebaran_append_powerplay_table(struct smu_context *smu)
 
 	if ((smc_dpm_table->table_header.format_revision == 4) &&
 	    (smc_dpm_table->table_header.content_revision == 10))
-		memcpy(&smc_pptable->GfxMaxCurrent,
-		       &smc_dpm_table->GfxMaxCurrent,
-		       sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_10, GfxMaxCurrent));
+		memcpy_trailing(smc_pptable, GfxMaxCurrent, reserved,
+				smc_dpm_table, GfxMaxCurrent);
 	return 0;
 }
 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs
  2021-08-18  6:05 ` [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs Kees Cook
@ 2021-08-20  7:49   ` Michael Ellerman
  2021-08-20  7:53     ` Christophe Leroy
  2021-08-20 15:55     ` Kees Cook
  0 siblings, 2 replies; 116+ messages in thread
From: Michael Ellerman @ 2021-08-20  7:49 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: Kees Cook, Benjamin Herrenschmidt, Paul Mackerras,
	Christophe Leroy, Sudeep Holla, linuxppc-dev, kernel test robot,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Kees Cook <keescook@chromium.org> writes:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
>
> Add a struct_group() for the spe registers so that memset() can correctly reason
> about the size:
>
>    In function 'fortify_memset_chk',
>        inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
>>> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>      195 |    __write_overflow_field();
>          |    ^~~~~~~~~~~~~~~~~~~~~~~~
>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: linuxppc-dev@lists.ozlabs.org
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/powerpc/include/asm/processor.h | 6 ++++--
>  arch/powerpc/kernel/signal_32.c      | 6 +++---
>  2 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
> index f348e564f7dd..05dc567cb9a8 100644
> --- a/arch/powerpc/include/asm/processor.h
> +++ b/arch/powerpc/include/asm/processor.h
> @@ -191,8 +191,10 @@ struct thread_struct {
>  	int		used_vsr;	/* set if process has used VSX */
>  #endif /* CONFIG_VSX */
>  #ifdef CONFIG_SPE
> -	unsigned long	evr[32];	/* upper 32-bits of SPE regs */
> -	u64		acc;		/* Accumulator */
> +	struct_group(spe,
> +		unsigned long	evr[32];	/* upper 32-bits of SPE regs */
> +		u64		acc;		/* Accumulator */
> +	);
>  	unsigned long	spefscr;	/* SPE & eFP status */
>  	unsigned long	spefscr_last;	/* SPEFSCR value on last prctl
>  					   call or trap return */
> diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
> index 0608581967f0..77b86caf5c51 100644
> --- a/arch/powerpc/kernel/signal_32.c
> +++ b/arch/powerpc/kernel/signal_32.c
> @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs,
>  	regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
>  	if (msr & MSR_SPE) {
>  		/* restore spe registers from the stack */
> -		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
> -				      ELF_NEVRREG * sizeof(u32), failed);
> +		unsafe_copy_from_user(&current->thread.spe, &sr->mc_vregs,
> +				      sizeof(current->thread.spe), failed);

This makes me nervous, because the ABI is that we copy ELF_NEVRREG *
sizeof(u32) bytes, not whatever sizeof(current->thread.spe) happens to
be.

ie. if we use sizeof an inadvertent change to the fields in
thread_struct could change how many bytes we copy out to userspace,
which would be an ABI break.

And that's not that hard to do, because it's not at all obvious that the
size and layout of fields in thread_struct affects the user ABI.

At the same time we don't want to copy the right number of bytes but
the wrong content, so from that point of view using sizeof is good :)

The way we handle it in ptrace is to have BUILD_BUG_ON()s to verify that
things match up, so maybe we should do that here too.

ie. add:

	BUILD_BUG_ON(sizeof(current->thread.spe) == ELF_NEVRREG * sizeof(u32));


Not sure if you are happy doing that as part of this patch. I can always
do it later if not.

cheers

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs
  2021-08-20  7:49   ` Michael Ellerman
@ 2021-08-20  7:53     ` Christophe Leroy
  2021-08-20 12:13       ` Michael Ellerman
  2021-08-20 15:55     ` Kees Cook
  1 sibling, 1 reply; 116+ messages in thread
From: Christophe Leroy @ 2021-08-20  7:53 UTC (permalink / raw)
  To: Michael Ellerman, Kees Cook, linux-kernel
  Cc: Benjamin Herrenschmidt, Paul Mackerras, Sudeep Holla,
	linuxppc-dev, kernel test robot, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening



Le 20/08/2021 à 09:49, Michael Ellerman a écrit :
> Kees Cook <keescook@chromium.org> writes:
>> In preparation for FORTIFY_SOURCE performing compile-time and run-time
>> field bounds checking for memset(), avoid intentionally writing across
>> neighboring fields.
>>
>> Add a struct_group() for the spe registers so that memset() can correctly reason
>> about the size:
>>
>>     In function 'fortify_memset_chk',
>>         inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
>>>> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>>       195 |    __write_overflow_field();
>>           |    ^~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Reported-by: kernel test robot <lkp@intel.com>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> ---
>>   arch/powerpc/include/asm/processor.h | 6 ++++--
>>   arch/powerpc/kernel/signal_32.c      | 6 +++---
>>   2 files changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
>> index f348e564f7dd..05dc567cb9a8 100644
>> --- a/arch/powerpc/include/asm/processor.h
>> +++ b/arch/powerpc/include/asm/processor.h
>> @@ -191,8 +191,10 @@ struct thread_struct {
>>   	int		used_vsr;	/* set if process has used VSX */
>>   #endif /* CONFIG_VSX */
>>   #ifdef CONFIG_SPE
>> -	unsigned long	evr[32];	/* upper 32-bits of SPE regs */
>> -	u64		acc;		/* Accumulator */
>> +	struct_group(spe,
>> +		unsigned long	evr[32];	/* upper 32-bits of SPE regs */
>> +		u64		acc;		/* Accumulator */
>> +	);
>>   	unsigned long	spefscr;	/* SPE & eFP status */
>>   	unsigned long	spefscr_last;	/* SPEFSCR value on last prctl
>>   					   call or trap return */
>> diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
>> index 0608581967f0..77b86caf5c51 100644
>> --- a/arch/powerpc/kernel/signal_32.c
>> +++ b/arch/powerpc/kernel/signal_32.c
>> @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs,
>>   	regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
>>   	if (msr & MSR_SPE) {
>>   		/* restore spe registers from the stack */
>> -		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
>> -				      ELF_NEVRREG * sizeof(u32), failed);
>> +		unsafe_copy_from_user(&current->thread.spe, &sr->mc_vregs,
>> +				      sizeof(current->thread.spe), failed);
> 
> This makes me nervous, because the ABI is that we copy ELF_NEVRREG *
> sizeof(u32) bytes, not whatever sizeof(current->thread.spe) happens to
> be.
> 
> ie. if we use sizeof an inadvertent change to the fields in
> thread_struct could change how many bytes we copy out to userspace,
> which would be an ABI break.
> 
> And that's not that hard to do, because it's not at all obvious that the
> size and layout of fields in thread_struct affects the user ABI.
> 
> At the same time we don't want to copy the right number of bytes but
> the wrong content, so from that point of view using sizeof is good :)
> 
> The way we handle it in ptrace is to have BUILD_BUG_ON()s to verify that
> things match up, so maybe we should do that here too.
> 
> ie. add:
> 
> 	BUILD_BUG_ON(sizeof(current->thread.spe) == ELF_NEVRREG * sizeof(u32));

You mean != I guess ?


> 
> 
> Not sure if you are happy doing that as part of this patch. I can always
> do it later if not.
> 
> cheers
> 

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs
  2021-08-20  7:53     ` Christophe Leroy
@ 2021-08-20 12:13       ` Michael Ellerman
  0 siblings, 0 replies; 116+ messages in thread
From: Michael Ellerman @ 2021-08-20 12:13 UTC (permalink / raw)
  To: Christophe Leroy, Kees Cook, linux-kernel
  Cc: Benjamin Herrenschmidt, Paul Mackerras, Sudeep Holla,
	linuxppc-dev, kernel test robot, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, netdev,
	dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 20/08/2021 à 09:49, Michael Ellerman a écrit :
>> Kees Cook <keescook@chromium.org> writes:
>>> In preparation for FORTIFY_SOURCE performing compile-time and run-time
>>> field bounds checking for memset(), avoid intentionally writing across
>>> neighboring fields.
>>>
>>> Add a struct_group() for the spe registers so that memset() can correctly reason
>>> about the size:
>>>
>>>     In function 'fortify_memset_chk',
>>>         inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
>>>>> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>>>       195 |    __write_overflow_field();
>>>           |    ^~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>> Cc: Paul Mackerras <paulus@samba.org>
>>> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
>>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>>> Cc: linuxppc-dev@lists.ozlabs.org
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>> ---
>>>   arch/powerpc/include/asm/processor.h | 6 ++++--
>>>   arch/powerpc/kernel/signal_32.c      | 6 +++---
>>>   2 files changed, 7 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
>>> index f348e564f7dd..05dc567cb9a8 100644
>>> --- a/arch/powerpc/include/asm/processor.h
>>> +++ b/arch/powerpc/include/asm/processor.h
>>> @@ -191,8 +191,10 @@ struct thread_struct {
>>>   	int		used_vsr;	/* set if process has used VSX */
>>>   #endif /* CONFIG_VSX */
>>>   #ifdef CONFIG_SPE
>>> -	unsigned long	evr[32];	/* upper 32-bits of SPE regs */
>>> -	u64		acc;		/* Accumulator */
>>> +	struct_group(spe,
>>> +		unsigned long	evr[32];	/* upper 32-bits of SPE regs */
>>> +		u64		acc;		/* Accumulator */
>>> +	);
>>>   	unsigned long	spefscr;	/* SPE & eFP status */
>>>   	unsigned long	spefscr_last;	/* SPEFSCR value on last prctl
>>>   					   call or trap return */
>>> diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
>>> index 0608581967f0..77b86caf5c51 100644
>>> --- a/arch/powerpc/kernel/signal_32.c
>>> +++ b/arch/powerpc/kernel/signal_32.c
>>> @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs,
>>>   	regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
>>>   	if (msr & MSR_SPE) {
>>>   		/* restore spe registers from the stack */
>>> -		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
>>> -				      ELF_NEVRREG * sizeof(u32), failed);
>>> +		unsafe_copy_from_user(&current->thread.spe, &sr->mc_vregs,
>>> +				      sizeof(current->thread.spe), failed);
>> 
>> This makes me nervous, because the ABI is that we copy ELF_NEVRREG *
>> sizeof(u32) bytes, not whatever sizeof(current->thread.spe) happens to
>> be.
>> 
>> ie. if we use sizeof an inadvertent change to the fields in
>> thread_struct could change how many bytes we copy out to userspace,
>> which would be an ABI break.
>> 
>> And that's not that hard to do, because it's not at all obvious that the
>> size and layout of fields in thread_struct affects the user ABI.
>> 
>> At the same time we don't want to copy the right number of bytes but
>> the wrong content, so from that point of view using sizeof is good :)
>> 
>> The way we handle it in ptrace is to have BUILD_BUG_ON()s to verify that
>> things match up, so maybe we should do that here too.
>> 
>> ie. add:
>> 
>> 	BUILD_BUG_ON(sizeof(current->thread.spe) == ELF_NEVRREG * sizeof(u32));
>
> You mean != I guess ?

Gah. Yes I do :)

cheers

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-19 18:14         ` Kees Cook
@ 2021-08-20 12:34           ` Jason Gunthorpe
  2021-08-20 15:56             ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Jason Gunthorpe @ 2021-08-20 12:34 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Leon Romanovsky, Doug Ledford, linux-rdma,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Thu, Aug 19, 2021 at 11:14:37AM -0700, Kees Cook wrote:

> Which do you mean? When doing the conversions I tended to opt for
> struct_group() since it provides more robust "intentionality". Strictly
> speaking, the new memset helpers are doing field-spanning writes, but the
> "clear to the end" pattern was so common it made sense to add the helpers,
> as they're a bit less disruptive. It's totally up to you! :)

Well, of the patches you cc'd to me only this one used the struct
group..

Jason 

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 22/63] HID: cp2112: Use struct_group() for memcpy() region
  2021-08-18  6:04 ` [PATCH v2 22/63] HID: cp2112: " Kees Cook
@ 2021-08-20 13:01   ` Jiri Kosina
  2021-08-20 15:48     ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Jiri Kosina @ 2021-08-20 13:01 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Tue, 17 Aug 2021, Kees Cook wrote:

> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), memmove(), and memset(), avoid
> intentionally writing across neighboring fields.
> 
> Use struct_group() in struct cp2112_string_report around members report,
> length, type, and string, so they can be referenced together. This will
> allow memcpy() and sizeof() to more easily reason about sizes, improve
> readability, and avoid future warnings about writing beyond the end of
> report.
> 
> "pahole" shows no size nor member offset changes to struct
> cp2112_string_report.  "objdump -d" shows no meaningful object
> code changes (i.e. only source line number induced differences.)
> 
> Cc: Jiri Kosina <jikos@kernel.org>
> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> Cc: linux-input@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event
  2021-08-18  6:05 ` [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event Kees Cook
@ 2021-08-20 13:02   ` Jiri Kosina
       [not found]     ` <CAJr-aD=6-g7VRw2Hw0dhs+RrtA=Tago5r6Dukfw_gGPB0YYKOQ@mail.gmail.com>
  0 siblings, 1 reply; 116+ messages in thread
From: Jiri Kosina @ 2021-08-20 13:02 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Stefan Achatz, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Tue, 17 Aug 2021, Kees Cook wrote:

> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Add struct_group() to mark region of struct kone_mouse_event that should
> be initialized to zero.
> 
> Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
> Cc: Jiri Kosina <jikos@kernel.org>
> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> Cc: linux-input@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Applied, thank you Kees.

-- 
Jiri Kosina
SUSE Labs


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event
       [not found]     ` <CAJr-aD=6-g7VRw2Hw0dhs+RrtA=Tago5r6Dukfw_gGPB0YYKOQ@mail.gmail.com>
@ 2021-08-20 15:27       ` Jiri Kosina
  2021-08-20 15:49         ` Kees Cook
  2021-08-20 15:57         ` Kees Cook
  0 siblings, 2 replies; 116+ messages in thread
From: Jiri Kosina @ 2021-08-20 15:27 UTC (permalink / raw)
  To: Kees Cook
  Cc: LKML, Stefan Achatz, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, Network Development,
	Maling list - DRI developers, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, 20 Aug 2021, Kees Cook wrote:

> > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > field bounds checking for memset(), avoid intentionally writing across
> > > neighboring fields.
> > >
> > > Add struct_group() to mark region of struct kone_mouse_event that should
> > > be initialized to zero.
> > >
> > > Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
> > > Cc: Jiri Kosina <jikos@kernel.org>
> > > Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > > Cc: linux-input@vger.kernel.org
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> >
> > Applied, thank you Kees.
> >
> 
> Eek! No, this will break the build: struct_group() is not yet in the tree.
> I can carry this with an Ack, etc.

I was pretty sure I saw struct_group() already in linux-next, but that was 
apparently a vacation-induced brainfart, sorry. Dropping.

-- 
Jiri Kosina
SUSE Labs


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 22/63] HID: cp2112: Use struct_group() for memcpy() region
  2021-08-20 13:01   ` Jiri Kosina
@ 2021-08-20 15:48     ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-20 15:48 UTC (permalink / raw)
  To: Jiri Kosina
  Cc: linux-kernel, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, Aug 20, 2021 at 03:01:43PM +0200, Jiri Kosina wrote:
> On Tue, 17 Aug 2021, Kees Cook wrote:
> 
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memcpy(), memmove(), and memset(), avoid
> > intentionally writing across neighboring fields.
> > 
> > Use struct_group() in struct cp2112_string_report around members report,
> > length, type, and string, so they can be referenced together. This will
> > allow memcpy() and sizeof() to more easily reason about sizes, improve
> > readability, and avoid future warnings about writing beyond the end of
> > report.
> > 
> > "pahole" shows no size nor member offset changes to struct
> > cp2112_string_report.  "objdump -d" shows no meaningful object
> > code changes (i.e. only source line number induced differences.)
> > 
> > Cc: Jiri Kosina <jikos@kernel.org>
> > Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > Cc: linux-input@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> 
> Applied, thanks.

I'm not sure if my other HTML email got through, but please don't apply
these to separate trees -- struct_group() is introduced as part of this
series.

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event
  2021-08-20 15:27       ` Jiri Kosina
@ 2021-08-20 15:49         ` Kees Cook
  2021-08-20 15:57         ` Kees Cook
  1 sibling, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-20 15:49 UTC (permalink / raw)
  To: Jiri Kosina
  Cc: LKML, Stefan Achatz, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, Network Development,
	Maling list - DRI developers, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, Aug 20, 2021 at 05:27:35PM +0200, Jiri Kosina wrote:
> On Fri, 20 Aug 2021, Kees Cook wrote:
> 
> > > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > > field bounds checking for memset(), avoid intentionally writing across
> > > > neighboring fields.
> > > >
> > > > Add struct_group() to mark region of struct kone_mouse_event that should
> > > > be initialized to zero.
> > > >
> > > > Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
> > > > Cc: Jiri Kosina <jikos@kernel.org>
> > > > Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > > > Cc: linux-input@vger.kernel.org
> > > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > >
> > > Applied, thank you Kees.
> > >
> > 
> > Eek! No, this will break the build: struct_group() is not yet in the tree.
> > I can carry this with an Ack, etc.
> 
> I was pretty sure I saw struct_group() already in linux-next, but that was 
> apparently a vacation-induced brainfart, sorry. Dropping.

Cool, no worries. Sorry for the confusion!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs
  2021-08-20  7:49   ` Michael Ellerman
  2021-08-20  7:53     ` Christophe Leroy
@ 2021-08-20 15:55     ` Kees Cook
  2021-08-23  4:55       ` Michael Ellerman
  1 sibling, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-20 15:55 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: linux-kernel, Benjamin Herrenschmidt, Paul Mackerras,
	Christophe Leroy, Sudeep Holla, linuxppc-dev, kernel test robot,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, Aug 20, 2021 at 05:49:35PM +1000, Michael Ellerman wrote:
> Kees Cook <keescook@chromium.org> writes:
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memset(), avoid intentionally writing across
> > neighboring fields.
> >
> > Add a struct_group() for the spe registers so that memset() can correctly reason
> > about the size:
> >
> >    In function 'fortify_memset_chk',
> >        inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
> >>> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
> >      195 |    __write_overflow_field();
> >          |    ^~~~~~~~~~~~~~~~~~~~~~~~
> >
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> > Cc: Sudeep Holla <sudeep.holla@arm.com>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Reported-by: kernel test robot <lkp@intel.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  arch/powerpc/include/asm/processor.h | 6 ++++--
> >  arch/powerpc/kernel/signal_32.c      | 6 +++---
> >  2 files changed, 7 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
> > index f348e564f7dd..05dc567cb9a8 100644
> > --- a/arch/powerpc/include/asm/processor.h
> > +++ b/arch/powerpc/include/asm/processor.h
> > @@ -191,8 +191,10 @@ struct thread_struct {
> >  	int		used_vsr;	/* set if process has used VSX */
> >  #endif /* CONFIG_VSX */
> >  #ifdef CONFIG_SPE
> > -	unsigned long	evr[32];	/* upper 32-bits of SPE regs */
> > -	u64		acc;		/* Accumulator */
> > +	struct_group(spe,
> > +		unsigned long	evr[32];	/* upper 32-bits of SPE regs */
> > +		u64		acc;		/* Accumulator */
> > +	);
> >  	unsigned long	spefscr;	/* SPE & eFP status */
> >  	unsigned long	spefscr_last;	/* SPEFSCR value on last prctl
> >  					   call or trap return */
> > diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
> > index 0608581967f0..77b86caf5c51 100644
> > --- a/arch/powerpc/kernel/signal_32.c
> > +++ b/arch/powerpc/kernel/signal_32.c
> > @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs,
> >  	regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
> >  	if (msr & MSR_SPE) {
> >  		/* restore spe registers from the stack */
> > -		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
> > -				      ELF_NEVRREG * sizeof(u32), failed);
> > +		unsafe_copy_from_user(&current->thread.spe, &sr->mc_vregs,
> > +				      sizeof(current->thread.spe), failed);
> 
> This makes me nervous, because the ABI is that we copy ELF_NEVRREG *
> sizeof(u32) bytes, not whatever sizeof(current->thread.spe) happens to
> be.
> 
> ie. if we use sizeof an inadvertent change to the fields in
> thread_struct could change how many bytes we copy out to userspace,
> which would be an ABI break.
> 
> And that's not that hard to do, because it's not at all obvious that the
> size and layout of fields in thread_struct affects the user ABI.
> 
> At the same time we don't want to copy the right number of bytes but
> the wrong content, so from that point of view using sizeof is good :)
> 
> The way we handle it in ptrace is to have BUILD_BUG_ON()s to verify that
> things match up, so maybe we should do that here too.
> 
> ie. add:
> 
> 	BUILD_BUG_ON(sizeof(current->thread.spe) == ELF_NEVRREG * sizeof(u32));
> 
> Not sure if you are happy doing that as part of this patch. I can always
> do it later if not.

Sounds good to me; I did that in a few other cases in the series where
the relationships between things seemed tenuous. :) I'll add this (as
!=) in v3.

Thanks!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr
  2021-08-20 12:34           ` Jason Gunthorpe
@ 2021-08-20 15:56             ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-20 15:56 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: linux-kernel, Leon Romanovsky, Doug Ledford, linux-rdma,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, Aug 20, 2021 at 09:34:00AM -0300, Jason Gunthorpe wrote:
> On Thu, Aug 19, 2021 at 11:14:37AM -0700, Kees Cook wrote:
> 
> > Which do you mean? When doing the conversions I tended to opt for
> > struct_group() since it provides more robust "intentionality". Strictly
> > speaking, the new memset helpers are doing field-spanning writes, but the
> > "clear to the end" pattern was so common it made sense to add the helpers,
> > as they're a bit less disruptive. It's totally up to you! :)
> 
> Well, of the patches you cc'd to me only this one used the struct
> group..

Understood. I've adjusted this for v3. Thanks!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event
  2021-08-20 15:27       ` Jiri Kosina
  2021-08-20 15:49         ` Kees Cook
@ 2021-08-20 15:57         ` Kees Cook
  2021-08-20 16:11           ` Jiri Kosina
  1 sibling, 1 reply; 116+ messages in thread
From: Kees Cook @ 2021-08-20 15:57 UTC (permalink / raw)
  To: Jiri Kosina
  Cc: LKML, Stefan Achatz, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, Network Development,
	Maling list - DRI developers, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, Aug 20, 2021 at 05:27:35PM +0200, Jiri Kosina wrote:
> On Fri, 20 Aug 2021, Kees Cook wrote:
> 
> > > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > > field bounds checking for memset(), avoid intentionally writing across
> > > > neighboring fields.
> > > >
> > > > Add struct_group() to mark region of struct kone_mouse_event that should
> > > > be initialized to zero.
> > > >
> > > > Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
> > > > Cc: Jiri Kosina <jikos@kernel.org>
> > > > Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > > > Cc: linux-input@vger.kernel.org
> > > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > >
> > > Applied, thank you Kees.
> > >
> > 
> > Eek! No, this will break the build: struct_group() is not yet in the tree.
> > I can carry this with an Ack, etc.
> 
> I was pretty sure I saw struct_group() already in linux-next, but that was 
> apparently a vacation-induced brainfart, sorry. Dropping.

Oh, for these two patches, can I add your Acked-by while I carry them?

Thanks!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event
  2021-08-20 15:57         ` Kees Cook
@ 2021-08-20 16:11           ` Jiri Kosina
  0 siblings, 0 replies; 116+ messages in thread
From: Jiri Kosina @ 2021-08-20 16:11 UTC (permalink / raw)
  To: Kees Cook
  Cc: LKML, Stefan Achatz, Benjamin Tissoires, linux-input,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, Network Development,
	Maling list - DRI developers, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Fri, 20 Aug 2021, Kees Cook wrote:

> > > > > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > > > > field bounds checking for memset(), avoid intentionally writing across
> > > > > neighboring fields.
> > > > >
> > > > > Add struct_group() to mark region of struct kone_mouse_event that should
> > > > > be initialized to zero.
> > > > >
> > > > > Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
> > > > > Cc: Jiri Kosina <jikos@kernel.org>
> > > > > Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > > > > Cc: linux-input@vger.kernel.org
> > > > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > >
> > > > Applied, thank you Kees.
> > > >
> > > 
> > > Eek! No, this will break the build: struct_group() is not yet in the tree.
> > > I can carry this with an Ack, etc.
> > 
> > I was pretty sure I saw struct_group() already in linux-next, but that was 
> > apparently a vacation-induced brainfart, sorry. Dropping.
> 
> Oh, for these two patches, can I add your Acked-by while I carry them?

Yes, thanks, and sorry for the noise.

-- 
Jiri Kosina
SUSE Labs


^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors
  2021-08-19 16:25     ` Kees Cook
@ 2021-08-21 10:17       ` Kalle Valo
  2021-08-22  8:11         ` Kees Cook
  0 siblings, 1 reply; 116+ messages in thread
From: Kalle Valo @ 2021-08-21 10:17 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, David S. Miller, Jakub Kicinski, ath11k,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Kees Cook <keescook@chromium.org> writes:

> On Thu, Aug 19, 2021 at 04:19:37PM +0300, Kalle Valo wrote:
>> Kees Cook <keescook@chromium.org> writes:
>> 
>> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
>> > field bounds checking for memset(), avoid intentionally writing across
>> > neighboring fields.
>> >
>> > Use memset_startat() so memset() doesn't get confused about writing
>> > beyond the destination member that is intended to be the starting point
>> > of zeroing through the end of the struct. Additionally split up a later
>> > field-spanning memset() so that memset() can reason about the size.
>> >
>> > Cc: Kalle Valo <kvalo@codeaurora.org>
>> > Cc: "David S. Miller" <davem@davemloft.net>
>> > Cc: Jakub Kicinski <kuba@kernel.org>
>> > Cc: ath11k@lists.infradead.org
>> > Cc: linux-wireless@vger.kernel.org
>> > Cc: netdev@vger.kernel.org
>> > Signed-off-by: Kees Cook <keescook@chromium.org>
>> 
>> To avoid conflicts I prefer taking this via my ath tree.
>
> The memset helpers are introduced as part of this series, so that makes
> things more difficult. Do you want me to create a branch with the
> helpers that you can merge?

Is this patch really worth the extra complexity? Why can't I apply this
ath11k patch after the helpers have landed Linus' tree? That would be
very simple.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors
  2021-08-21 10:17       ` Kalle Valo
@ 2021-08-22  8:11         ` Kees Cook
  0 siblings, 0 replies; 116+ messages in thread
From: Kees Cook @ 2021-08-22  8:11 UTC (permalink / raw)
  To: Kalle Valo
  Cc: linux-kernel, David S. Miller, Jakub Kicinski, ath11k,
	linux-wireless, netdev, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On Sat, Aug 21, 2021 at 01:17:36PM +0300, Kalle Valo wrote:
> Kees Cook <keescook@chromium.org> writes:
> 
> > On Thu, Aug 19, 2021 at 04:19:37PM +0300, Kalle Valo wrote:
> >> Kees Cook <keescook@chromium.org> writes:
> >> 
> >> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> >> > field bounds checking for memset(), avoid intentionally writing across
> >> > neighboring fields.
> >> >
> >> > Use memset_startat() so memset() doesn't get confused about writing
> >> > beyond the destination member that is intended to be the starting point
> >> > of zeroing through the end of the struct. Additionally split up a later
> >> > field-spanning memset() so that memset() can reason about the size.
> >> >
> >> > Cc: Kalle Valo <kvalo@codeaurora.org>
> >> > Cc: "David S. Miller" <davem@davemloft.net>
> >> > Cc: Jakub Kicinski <kuba@kernel.org>
> >> > Cc: ath11k@lists.infradead.org
> >> > Cc: linux-wireless@vger.kernel.org
> >> > Cc: netdev@vger.kernel.org
> >> > Signed-off-by: Kees Cook <keescook@chromium.org>
> >> 
> >> To avoid conflicts I prefer taking this via my ath tree.
> >
> > The memset helpers are introduced as part of this series, so that makes
> > things more difficult. Do you want me to create a branch with the
> > helpers that you can merge?
> 
> Is this patch really worth the extra complexity? Why can't I apply this
> ath11k patch after the helpers have landed Linus' tree? That would be
> very simple.

Not singularly, no. But I have a bit of a catch-22 in that I can't turn
on greater FORTIFY strictness without first fixing the false positives,
and I can't fix the false positives in "other" trees without those trees
first having the helpers that get introduced by the FORTIFY series. :)

Anyway, since we're close to the merge window anyway, the FORTIFY series
won't land in 1 release at this point regardless, so I'll just get
the helpers landed and we can do the individual pieces once the merge
window closes.

Wheee :)

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs
  2021-08-20 15:55     ` Kees Cook
@ 2021-08-23  4:55       ` Michael Ellerman
  0 siblings, 0 replies; 116+ messages in thread
From: Michael Ellerman @ 2021-08-23  4:55 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, Benjamin Herrenschmidt, Paul Mackerras,
	Christophe Leroy, Sudeep Holla, linuxppc-dev, kernel test robot,
	Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, netdev, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

Kees Cook <keescook@chromium.org> writes:
> On Fri, Aug 20, 2021 at 05:49:35PM +1000, Michael Ellerman wrote:
>> Kees Cook <keescook@chromium.org> writes:
>> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
>> > field bounds checking for memset(), avoid intentionally writing across
>> > neighboring fields.
>> >
>> > Add a struct_group() for the spe registers so that memset() can correctly reason
>> > about the size:
>> >
>> >    In function 'fortify_memset_chk',
>> >        inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3:
>> >>> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>> >      195 |    __write_overflow_field();
>> >          |    ^~~~~~~~~~~~~~~~~~~~~~~~
>> >
>> > Cc: Michael Ellerman <mpe@ellerman.id.au>
>> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> > Cc: Paul Mackerras <paulus@samba.org>
>> > Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
>> > Cc: Sudeep Holla <sudeep.holla@arm.com>
>> > Cc: linuxppc-dev@lists.ozlabs.org
>> > Reported-by: kernel test robot <lkp@intel.com>
>> > Signed-off-by: Kees Cook <keescook@chromium.org>
>> > ---
>> >  arch/powerpc/include/asm/processor.h | 6 ++++--
>> >  arch/powerpc/kernel/signal_32.c      | 6 +++---
>> >  2 files changed, 7 insertions(+), 5 deletions(-)
>> >
>> > diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
>> > index f348e564f7dd..05dc567cb9a8 100644
>> > --- a/arch/powerpc/include/asm/processor.h
>> > +++ b/arch/powerpc/include/asm/processor.h
>> > @@ -191,8 +191,10 @@ struct thread_struct {
>> >  	int		used_vsr;	/* set if process has used VSX */
>> >  #endif /* CONFIG_VSX */
>> >  #ifdef CONFIG_SPE
>> > -	unsigned long	evr[32];	/* upper 32-bits of SPE regs */
>> > -	u64		acc;		/* Accumulator */
>> > +	struct_group(spe,
>> > +		unsigned long	evr[32];	/* upper 32-bits of SPE regs */
>> > +		u64		acc;		/* Accumulator */
>> > +	);
>> >  	unsigned long	spefscr;	/* SPE & eFP status */
>> >  	unsigned long	spefscr_last;	/* SPEFSCR value on last prctl
>> >  					   call or trap return */
>> > diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
>> > index 0608581967f0..77b86caf5c51 100644
>> > --- a/arch/powerpc/kernel/signal_32.c
>> > +++ b/arch/powerpc/kernel/signal_32.c
>> > @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs,
>> >  	regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
>> >  	if (msr & MSR_SPE) {
>> >  		/* restore spe registers from the stack */
>> > -		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
>> > -				      ELF_NEVRREG * sizeof(u32), failed);
>> > +		unsafe_copy_from_user(&current->thread.spe, &sr->mc_vregs,
>> > +				      sizeof(current->thread.spe), failed);
>> 
>> This makes me nervous, because the ABI is that we copy ELF_NEVRREG *
>> sizeof(u32) bytes, not whatever sizeof(current->thread.spe) happens to
>> be.
>> 
>> ie. if we use sizeof an inadvertent change to the fields in
>> thread_struct could change how many bytes we copy out to userspace,
>> which would be an ABI break.
>> 
>> And that's not that hard to do, because it's not at all obvious that the
>> size and layout of fields in thread_struct affects the user ABI.
>> 
>> At the same time we don't want to copy the right number of bytes but
>> the wrong content, so from that point of view using sizeof is good :)
>> 
>> The way we handle it in ptrace is to have BUILD_BUG_ON()s to verify that
>> things match up, so maybe we should do that here too.
>> 
>> ie. add:
>> 
>> 	BUILD_BUG_ON(sizeof(current->thread.spe) == ELF_NEVRREG * sizeof(u32));
>> 
>> Not sure if you are happy doing that as part of this patch. I can always
>> do it later if not.
>
> Sounds good to me; I did that in a few other cases in the series where
> the relationships between things seemed tenuous. :) I'll add this (as
> !=) in v3.

Thanks.

cheers

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 47/63] intel_th: msu: Use memset_startat() for clearing hw header
  2021-08-18  6:05 ` [PATCH v2 47/63] intel_th: msu: Use memset_startat() for clearing hw header Kees Cook
@ 2021-08-24  7:38   ` Alexander Shishkin
  0 siblings, 0 replies; 116+ messages in thread
From: Alexander Shishkin @ 2021-08-24  7:38 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: Kees Cook, Gustavo A. R. Silva, Greg Kroah-Hartman,
	Andrew Morton, linux-wireless, netdev, dri-devel, linux-staging,
	linux-block, linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening, alexander.shishkin

Kees Cook <keescook@chromium.org> writes:

> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
>
> Use memset_startat() so memset() doesn't get confused about writing
> beyond the destination member that is intended to be the starting point
> of zeroing through the end of the struct.
>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>

> ---
>  drivers/hwtracing/intel_th/msu.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
> index 432ade0842f6..70a07b4e9967 100644
> --- a/drivers/hwtracing/intel_th/msu.c
> +++ b/drivers/hwtracing/intel_th/msu.c
> @@ -658,13 +658,11 @@ static void msc_buffer_clear_hw_header(struct msc *msc)
>  
>  	list_for_each_entry(win, &msc->win_list, entry) {
>  		unsigned int blk;
> -		size_t hw_sz = sizeof(struct msc_block_desc) -
> -			offsetof(struct msc_block_desc, hw_tag);
>  
>  		for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
>  			struct msc_block_desc *bdesc = sg_virt(sg);
>  
> -			memset(&bdesc->hw_tag, 0, hw_sz);
> +			memset_startat(bdesc, 0, hw_tag);
>  		}
>  	}
>  }
> -- 
> 2.30.2

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group()
  2021-08-18  6:04 ` [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group() Kees Cook
@ 2021-09-01 13:46   ` Jason A. Donenfeld
  0 siblings, 0 replies; 116+ messages in thread
From: Jason A. Donenfeld @ 2021-09-01 13:46 UTC (permalink / raw)
  To: Kees Cook
  Cc: LKML, David S. Miller, Jakub Kicinski, Jonathan Lemon,
	Alexander Lobakin, Jakub Sitnicki, Marco Elver, Willem de Bruijn,
	WireGuard mailing list, Netdev, Gustavo A . R . Silva,
	Greg Kroah-Hartman, Andrew Morton, linux-wireless, dri-devel,
	linux-staging, linux-block, Linux Kbuild mailing list,
	clang-built-linux, Rasmus Villemoes, linux-hardening

For the drivers/net/wireguard part,

Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 60/63] net/af_iucv: Use struct_group() to zero struct iucv_sock region
  2021-08-18  6:05 ` [PATCH v2 60/63] net/af_iucv: Use struct_group() to zero struct iucv_sock region Kees Cook
@ 2021-09-09  6:14   ` Karsten Graul
  0 siblings, 0 replies; 116+ messages in thread
From: Karsten Graul @ 2021-09-09  6:14 UTC (permalink / raw)
  To: Kees Cook, linux-kernel
  Cc: Julian Wiedmann, David S. Miller, Jakub Kicinski, linux-s390,
	netdev, Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	linux-wireless, dri-devel, linux-staging, linux-block,
	linux-kbuild, clang-built-linux, Rasmus Villemoes,
	linux-hardening

On 18/08/2021 08:05, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
> 
> Add struct_group() to mark the region of struct iucv_sock that gets
> initialized to zero. Avoid the future warning:
> 
> In function 'fortify_memset_chk',
>     inlined from 'iucv_sock_alloc' at net/iucv/af_iucv.c:476:2:
> ./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
>   199 |    __write_overflow_field(p_size_field, size);
>       |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Cc: Julian Wiedmann <jwi@linux.ibm.com>
> Cc: Karsten Graul <kgraul@linux.ibm.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: linux-s390@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  include/net/iucv/af_iucv.h | 10 ++++++----
>  net/iucv/af_iucv.c         |  2 +-
>  2 files changed, 7 insertions(+), 5 deletions(-)

No objections.
Acked-by: Karsten Graul <kgraul@linux.ibm.com>

Thank you.

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 12/63] thermal: intel: int340x_thermal: Use struct_group() for memcpy() region
  2021-08-18  6:04 ` [PATCH v2 12/63] thermal: intel: int340x_thermal: " Kees Cook
@ 2021-11-23 13:19   ` Rafael J. Wysocki
  2021-11-23 23:53     ` Srinivas Pandruvada
  0 siblings, 1 reply; 116+ messages in thread
From: Rafael J. Wysocki @ 2021-11-23 13:19 UTC (permalink / raw)
  To: Kees Cook, Zhang Rui, Srinivas Pandruvada
  Cc: Linux Kernel Mailing List, Daniel Lezcano, Amit Kucheria,
	Linux PM, Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	open list:NETWORKING DRIVERS (WIRELESS),
	netdev, dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Aug 18, 2021 at 8:08 AM Kees Cook <keescook@chromium.org> wrote:
>
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), avoid intentionally writing across
> neighboring fields.
>
> Use struct_group() in struct art around members weight, and ac[0-9]_max,
> so they can be referenced together. This will allow memcpy() and sizeof()
> to more easily reason about sizes, improve readability, and avoid future
> warnings about writing beyond the end of weight.
>
> "pahole" shows no size nor member offset changes to struct art.
> "objdump -d" shows no meaningful object code changes (i.e. only source
> line number induced differences).
>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Amit Kucheria <amitk@kernel.org>
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Rui, Srinivas, any comments here?

> ---
>  .../intel/int340x_thermal/acpi_thermal_rel.c  |  5 +-
>  .../intel/int340x_thermal/acpi_thermal_rel.h  | 48 ++++++++++---------
>  2 files changed, 29 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> index a478cff8162a..e90690a234c4 100644
> --- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> +++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> @@ -250,8 +250,9 @@ static int fill_art(char __user *ubuf)
>                 get_single_name(arts[i].source, art_user[i].source_device);
>                 get_single_name(arts[i].target, art_user[i].target_device);
>                 /* copy the rest int data in addition to source and target */
> -               memcpy(&art_user[i].weight, &arts[i].weight,
> -                       sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
> +               BUILD_BUG_ON(sizeof(art_user[i].data) !=
> +                            sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
> +               memcpy(&art_user[i].data, &arts[i].data, sizeof(art_user[i].data));
>         }
>
>         if (copy_to_user(ubuf, art_user, art_len))
> diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> index 58822575fd54..78d942477035 100644
> --- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> +++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> @@ -17,17 +17,19 @@
>  struct art {
>         acpi_handle source;
>         acpi_handle target;
> -       u64 weight;
> -       u64 ac0_max;
> -       u64 ac1_max;
> -       u64 ac2_max;
> -       u64 ac3_max;
> -       u64 ac4_max;
> -       u64 ac5_max;
> -       u64 ac6_max;
> -       u64 ac7_max;
> -       u64 ac8_max;
> -       u64 ac9_max;
> +       struct_group(data,
> +               u64 weight;
> +               u64 ac0_max;
> +               u64 ac1_max;
> +               u64 ac2_max;
> +               u64 ac3_max;
> +               u64 ac4_max;
> +               u64 ac5_max;
> +               u64 ac6_max;
> +               u64 ac7_max;
> +               u64 ac8_max;
> +               u64 ac9_max;
> +       );
>  } __packed;
>
>  struct trt {
> @@ -47,17 +49,19 @@ union art_object {
>         struct {
>                 char source_device[8]; /* ACPI single name */
>                 char target_device[8]; /* ACPI single name */
> -               u64 weight;
> -               u64 ac0_max_level;
> -               u64 ac1_max_level;
> -               u64 ac2_max_level;
> -               u64 ac3_max_level;
> -               u64 ac4_max_level;
> -               u64 ac5_max_level;
> -               u64 ac6_max_level;
> -               u64 ac7_max_level;
> -               u64 ac8_max_level;
> -               u64 ac9_max_level;
> +               struct_group(data,
> +                       u64 weight;
> +                       u64 ac0_max_level;
> +                       u64 ac1_max_level;
> +                       u64 ac2_max_level;
> +                       u64 ac3_max_level;
> +                       u64 ac4_max_level;
> +                       u64 ac5_max_level;
> +                       u64 ac6_max_level;
> +                       u64 ac7_max_level;
> +                       u64 ac8_max_level;
> +                       u64 ac9_max_level;
> +               );
>         };
>         u64 __data[ACPI_NR_ART_ELEMENTS];
>  };
> --
> 2.30.2
>

^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 12/63] thermal: intel: int340x_thermal: Use struct_group() for memcpy() region
  2021-11-23 13:19   ` Rafael J. Wysocki
@ 2021-11-23 23:53     ` Srinivas Pandruvada
  2021-11-24 13:33       ` Rafael J. Wysocki
  0 siblings, 1 reply; 116+ messages in thread
From: Srinivas Pandruvada @ 2021-11-23 23:53 UTC (permalink / raw)
  To: Rafael J. Wysocki, Kees Cook, Zhang Rui
  Cc: Linux Kernel Mailing List, Daniel Lezcano, Amit Kucheria,
	Linux PM, Gustavo A. R. Silva, Greg Kroah-Hartman, Andrew Morton,
	open list:NETWORKING DRIVERS (WIRELESS),
	netdev, dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Tue, 2021-11-23 at 14:19 +0100, Rafael J. Wysocki wrote:
> On Wed, Aug 18, 2021 at 8:08 AM Kees Cook <keescook@chromium.org>
> wrote:
> > 
> > In preparation for FORTIFY_SOURCE performing compile-time and run-
> > time
> > field bounds checking for memcpy(), avoid intentionally writing
> > across
> > neighboring fields.
> > 
> > Use struct_group() in struct art around members weight, and ac[0-
> > 9]_max,
> > so they can be referenced together. This will allow memcpy() and
> > sizeof()
> > to more easily reason about sizes, improve readability, and avoid
> > future
> > warnings about writing beyond the end of weight.
> > 
> > "pahole" shows no size nor member offset changes to struct art.
> > "objdump -d" shows no meaningful object code changes (i.e. only
> > source
> > line number induced differences).
> > 
> > Cc: Zhang Rui <rui.zhang@intel.com>
> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> > Cc: Amit Kucheria <amitk@kernel.org>
> > Cc: linux-pm@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> 
> Rui, Srinivas, any comments here?
Looks good.
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Thanks,
Srinivas

> 
> > ---
> >  .../intel/int340x_thermal/acpi_thermal_rel.c  |  5 +-
> >  .../intel/int340x_thermal/acpi_thermal_rel.h  | 48 ++++++++++-------
> > --
> >  2 files changed, 29 insertions(+), 24 deletions(-)
> > 
> > diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > index a478cff8162a..e90690a234c4 100644
> > --- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > +++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > @@ -250,8 +250,9 @@ static int fill_art(char __user *ubuf)
> >                 get_single_name(arts[i].source,
> > art_user[i].source_device);
> >                 get_single_name(arts[i].target,
> > art_user[i].target_device);
> >                 /* copy the rest int data in addition to source and
> > target */
> > -               memcpy(&art_user[i].weight, &arts[i].weight,
> > -                       sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
> > +               BUILD_BUG_ON(sizeof(art_user[i].data) !=
> > +                            sizeof(u64) * (ACPI_NR_ART_ELEMENTS -
> > 2));
> > +               memcpy(&art_user[i].data, &arts[i].data,
> > sizeof(art_user[i].data));
> >         }
> > 
> >         if (copy_to_user(ubuf, art_user, art_len))
> > diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> > b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> > index 58822575fd54..78d942477035 100644
> > --- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> > +++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
> > @@ -17,17 +17,19 @@
> >  struct art {
> >         acpi_handle source;
> >         acpi_handle target;
> > -       u64 weight;
> > -       u64 ac0_max;
> > -       u64 ac1_max;
> > -       u64 ac2_max;
> > -       u64 ac3_max;
> > -       u64 ac4_max;
> > -       u64 ac5_max;
> > -       u64 ac6_max;
> > -       u64 ac7_max;
> > -       u64 ac8_max;
> > -       u64 ac9_max;
> > +       struct_group(data,
> > +               u64 weight;
> > +               u64 ac0_max;
> > +               u64 ac1_max;
> > +               u64 ac2_max;
> > +               u64 ac3_max;
> > +               u64 ac4_max;
> > +               u64 ac5_max;
> > +               u64 ac6_max;
> > +               u64 ac7_max;
> > +               u64 ac8_max;
> > +               u64 ac9_max;
> > +       );
> >  } __packed;
> > 
> >  struct trt {
> > @@ -47,17 +49,19 @@ union art_object {
> >         struct {
> >                 char source_device[8]; /* ACPI single name */
> >                 char target_device[8]; /* ACPI single name */
> > -               u64 weight;
> > -               u64 ac0_max_level;
> > -               u64 ac1_max_level;
> > -               u64 ac2_max_level;
> > -               u64 ac3_max_level;
> > -               u64 ac4_max_level;
> > -               u64 ac5_max_level;
> > -               u64 ac6_max_level;
> > -               u64 ac7_max_level;
> > -               u64 ac8_max_level;
> > -               u64 ac9_max_level;
> > +               struct_group(data,
> > +                       u64 weight;
> > +                       u64 ac0_max_level;
> > +                       u64 ac1_max_level;
> > +                       u64 ac2_max_level;
> > +                       u64 ac3_max_level;
> > +                       u64 ac4_max_level;
> > +                       u64 ac5_max_level;
> > +                       u64 ac6_max_level;
> > +                       u64 ac7_max_level;
> > +                       u64 ac8_max_level;
> > +                       u64 ac9_max_level;
> > +               );
> >         };
> >         u64 __data[ACPI_NR_ART_ELEMENTS];
> >  };
> > --
> > 2.30.2
> > 



^ permalink raw reply	[flat|nested] 116+ messages in thread

* Re: [PATCH v2 12/63] thermal: intel: int340x_thermal: Use struct_group() for memcpy() region
  2021-11-23 23:53     ` Srinivas Pandruvada
@ 2021-11-24 13:33       ` Rafael J. Wysocki
  0 siblings, 0 replies; 116+ messages in thread
From: Rafael J. Wysocki @ 2021-11-24 13:33 UTC (permalink / raw)
  To: Srinivas Pandruvada, Kees Cook
  Cc: Rafael J. Wysocki, Zhang Rui, Linux Kernel Mailing List,
	Daniel Lezcano, Amit Kucheria, Linux PM, Gustavo A. R. Silva,
	Greg Kroah-Hartman, Andrew Morton,
	open list:NETWORKING DRIVERS (WIRELESS),
	netdev, dri-devel, linux-staging, linux-block, linux-kbuild,
	clang-built-linux, Rasmus Villemoes, linux-hardening

On Wed, Nov 24, 2021 at 12:53 AM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
>
> On Tue, 2021-11-23 at 14:19 +0100, Rafael J. Wysocki wrote:
> > On Wed, Aug 18, 2021 at 8:08 AM Kees Cook <keescook@chromium.org>
> > wrote:
> > >
> > > In preparation for FORTIFY_SOURCE performing compile-time and run-
> > > time
> > > field bounds checking for memcpy(), avoid intentionally writing
> > > across
> > > neighboring fields.
> > >
> > > Use struct_group() in struct art around members weight, and ac[0-
> > > 9]_max,
> > > so they can be referenced together. This will allow memcpy() and
> > > sizeof()
> > > to more easily reason about sizes, improve readability, and avoid
> > > future
> > > warnings about writing beyond the end of weight.
> > >
> > > "pahole" shows no size nor member offset changes to struct art.
> > > "objdump -d" shows no meaningful object code changes (i.e. only
> > > source
> > > line number induced differences).
> > >
> > > Cc: Zhang Rui <rui.zhang@intel.com>
> > > Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> > > Cc: Amit Kucheria <amitk@kernel.org>
> > > Cc: linux-pm@vger.kernel.org
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> >
> > Rui, Srinivas, any comments here?
> Looks good.
> Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Applied as 5.17 material, thank you!

^ permalink raw reply	[flat|nested] 116+ messages in thread

end of thread, other threads:[~2021-11-24 14:35 UTC | newest]

Thread overview: 116+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-18  6:04 [PATCH v2 00/63] Introduce strict memcpy() bounds checking Kees Cook
2021-08-18  6:04 ` [PATCH v2 01/63] ipw2x00: Avoid field-overflowing memcpy() Kees Cook
2021-08-18  6:04 ` [PATCH v2 02/63] net/mlx5e: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 03/63] rpmsg: glink: Replace strncpy() with strscpy_pad() Kees Cook
2021-08-18  6:04 ` [PATCH v2 04/63] pcmcia: ray_cs: Split memcpy() to avoid bounds check warning Kees Cook
2021-08-18  6:04 ` [PATCH v2 05/63] stddef: Introduce struct_group() helper macro Kees Cook
2021-08-18 22:35   ` Dan Williams
2021-08-18  6:04 ` [PATCH v2 06/63] cxl/core: Replace unions with struct_group() Kees Cook
2021-08-18 22:36   ` Dan Williams
2021-08-18  6:04 ` [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group() Kees Cook
2021-09-01 13:46   ` Jason A. Donenfeld
2021-08-18  6:04 ` [PATCH v2 08/63] bnxt_en: Use struct_group_attr() for memcpy() region Kees Cook
2021-08-18  6:04 ` [PATCH v2 09/63] mwl8k: Use struct_group() " Kees Cook
2021-08-18  6:04 ` [PATCH v2 10/63] libertas: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 11/63] libertas_tf: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 12/63] thermal: intel: int340x_thermal: " Kees Cook
2021-11-23 13:19   ` Rafael J. Wysocki
2021-11-23 23:53     ` Srinivas Pandruvada
2021-11-24 13:33       ` Rafael J. Wysocki
2021-08-18  6:04 ` [PATCH v2 13/63] iommu/amd: " Kees Cook
2021-08-18 11:34   ` Joerg Roedel
2021-08-18  6:04 ` [PATCH v2 14/63] cxgb3: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 15/63] intersil: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 16/63] cxgb4: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 17/63] bnx2x: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 18/63] drm/amd/pm: " Kees Cook
2021-08-18 11:42   ` Lazar, Lijo
2021-08-18 23:59     ` Kees Cook
2021-08-19  5:03       ` Lazar, Lijo
2021-08-19 19:58         ` Kees Cook
2021-08-18  6:04 ` [PATCH v2 19/63] staging: wlan-ng: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 20/63] drm/mga/mga_ioc32: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 21/63] net/mlx5e: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 22/63] HID: cp2112: " Kees Cook
2021-08-20 13:01   ` Jiri Kosina
2021-08-20 15:48     ` Kees Cook
2021-08-18  6:04 ` [PATCH v2 23/63] media: omap3isp: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 24/63] sata_fsl: " Kees Cook
2021-08-18  6:04 ` [PATCH v2 25/63] compiler_types.h: Remove __compiletime_object_size() Kees Cook
2021-08-18 13:02   ` Miguel Ojeda
2021-08-18  6:04 ` [PATCH v2 26/63] lib/string: Move helper functions out of string.c Kees Cook
2021-08-18  9:35   ` Andy Shevchenko
2021-08-18  6:04 ` [PATCH v2 27/63] fortify: Move remaining fortify helpers into fortify-string.h Kees Cook
2021-08-18 19:05   ` Francis Laniel
2021-08-18  6:04 ` [PATCH v2 28/63] fortify: Explicitly disable Clang support Kees Cook
2021-08-18  6:04 ` [PATCH v2 29/63] fortify: Fix dropped strcpy() compile-time write overflow check Kees Cook
2021-08-18  6:05 ` [PATCH v2 30/63] fortify: Prepare to improve strnlen() and strlen() warnings Kees Cook
2021-08-18  6:05 ` [PATCH v2 31/63] fortify: Allow strlen() and strnlen() to pass compile-time known lengths Kees Cook
2021-08-18  6:05 ` [PATCH v2 32/63] fortify: Add compile-time FORTIFY_SOURCE tests Kees Cook
2021-08-18  6:05 ` [PATCH v2 33/63] lib: Introduce CONFIG_TEST_MEMCPY Kees Cook
2021-08-18  6:05 ` [PATCH v2 34/63] fortify: Detect struct member overflows in memcpy() at compile-time Kees Cook
2021-08-18  6:05 ` [PATCH v2 35/63] fortify: Detect struct member overflows in memmove() " Kees Cook
2021-08-18  6:05 ` [PATCH v2 36/63] scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp Kees Cook
2021-08-18  6:05 ` [PATCH v2 37/63] string.h: Introduce memset_after() for wiping trailing members/padding Kees Cook
2021-08-18  6:05 ` [PATCH v2 38/63] xfrm: Use memset_after() to clear padding Kees Cook
2021-08-18  6:05 ` [PATCH v2 39/63] ipv6: Use memset_after() to zero rt6_info Kees Cook
2021-08-18  6:05 ` [PATCH v2 40/63] netfilter: conntrack: Use memset_startat() to zero struct nf_conn Kees Cook
2021-08-18  6:05 ` [PATCH v2 41/63] net: 802: Use memset_startat() to clear struct fields Kees Cook
2021-08-18  6:05 ` [PATCH v2 42/63] net: dccp: Use memset_startat() for TP zeroing Kees Cook
2021-08-18  6:05 ` [PATCH v2 43/63] net: qede: Use memset_startat() for counters Kees Cook
2021-08-18  6:05 ` [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status Kees Cook
2021-08-18  7:08   ` Johannes Berg
2021-08-18  8:06     ` Johannes Berg
2021-08-18  9:05       ` Kees Cook
2021-08-18  6:05 ` [PATCH v2 45/63] ath11k: Use memset_startat() for clearing queue descriptors Kees Cook
2021-08-19 13:19   ` Kalle Valo
2021-08-19 16:25     ` Kees Cook
2021-08-21 10:17       ` Kalle Valo
2021-08-22  8:11         ` Kees Cook
2021-08-18  6:05 ` [PATCH v2 46/63] iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl Kees Cook
2021-08-18  6:05 ` [PATCH v2 47/63] intel_th: msu: Use memset_startat() for clearing hw header Kees Cook
2021-08-24  7:38   ` Alexander Shishkin
2021-08-18  6:05 ` [PATCH v2 48/63] IB/mthca: Use memset_startat() for clearing mpt_entry Kees Cook
2021-08-18  6:05 ` [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct Kees Cook
2021-08-18  6:35   ` Nikolay Borisov
2021-08-18  9:28   ` David Sterba
2021-08-18  6:05 ` [PATCH v2 50/63] tracing: Use memset_startat() to zero struct trace_iterator Kees Cook
2021-08-18 13:33   ` Steven Rostedt
2021-08-18 16:21     ` Kees Cook
2021-08-18  6:05 ` [PATCH v2 51/63] drbd: Use struct_group() to zero algs Kees Cook
2021-08-18  6:05 ` [PATCH v2 52/63] cm4000_cs: Use struct_group() to zero struct cm4000_dev region Kees Cook
2021-08-18  6:05 ` [PATCH v2 53/63] KVM: x86: Use struct_group() to zero decode cache Kees Cook
2021-08-18 15:11   ` Sean Christopherson
2021-08-18 16:23     ` Kees Cook
2021-08-18 22:53       ` Sean Christopherson
2021-08-18 23:06         ` Kees Cook
2021-08-18  6:05 ` [PATCH v2 54/63] dm integrity: Use struct_group() to zero struct journal_sector Kees Cook
2021-08-18  6:05 ` [PATCH v2 55/63] HID: roccat: Use struct_group() to zero kone_mouse_event Kees Cook
2021-08-20 13:02   ` Jiri Kosina
     [not found]     ` <CAJr-aD=6-g7VRw2Hw0dhs+RrtA=Tago5r6Dukfw_gGPB0YYKOQ@mail.gmail.com>
2021-08-20 15:27       ` Jiri Kosina
2021-08-20 15:49         ` Kees Cook
2021-08-20 15:57         ` Kees Cook
2021-08-20 16:11           ` Jiri Kosina
2021-08-18  6:05 ` [PATCH v2 56/63] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr Kees Cook
2021-08-19 12:27   ` Jason Gunthorpe
2021-08-19 16:19     ` Kees Cook
2021-08-19 16:47       ` Jason Gunthorpe
2021-08-19 18:14         ` Kees Cook
2021-08-20 12:34           ` Jason Gunthorpe
2021-08-20 15:56             ` Kees Cook
2021-08-18  6:05 ` [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs Kees Cook
2021-08-20  7:49   ` Michael Ellerman
2021-08-20  7:53     ` Christophe Leroy
2021-08-20 12:13       ` Michael Ellerman
2021-08-20 15:55     ` Kees Cook
2021-08-23  4:55       ` Michael Ellerman
2021-08-18  6:05 ` [PATCH v2 58/63] ethtool: stats: Use struct_group() to clear all stats at once Kees Cook
2021-08-18  6:05 ` [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions Kees Cook
2021-08-18  6:26   ` Marc Kleine-Budde
2021-08-18  6:05 ` [PATCH v2 60/63] net/af_iucv: Use struct_group() to zero struct iucv_sock region Kees Cook
2021-09-09  6:14   ` Karsten Graul
2021-08-18  6:05 ` [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow Kees Cook
2021-08-18  6:42   ` Christophe Leroy
2021-08-18 22:30     ` Kees Cook
2021-08-18  6:05 ` [PATCH v2 62/63] fortify: Detect struct member overflows in memset() at compile-time Kees Cook
2021-08-18  6:05 ` [PATCH v2 63/63] fortify: Work around Clang inlining bugs Kees Cook

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).