From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
"Jason A. Donenfeld" <Jason@zx2c4.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jonathan Lemon <jonathan.lemon@gmail.com>,
Alexander Lobakin <alobakin@pm.me>,
Jakub Sitnicki <jakub@cloudflare.com>,
Marco Elver <elver@google.com>,
Willem de Bruijn <willemb@google.com>,
wireguard@lists.zx2c4.com, netdev@vger.kernel.org,
"Gustavo A . R . Silva" <gustavoars@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-wireless@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-staging@lists.linux.dev, linux-block@vger.kernel.org,
linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
linux-hardening@vger.kernel.org
Subject: [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group()
Date: Tue, 17 Aug 2021 23:04:37 -0700 [thread overview]
Message-ID: <20210818060533.3569517-8-keescook@chromium.org> (raw)
In-Reply-To: <20210818060533.3569517-1-keescook@chromium.org>
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
next prev parent reply other threads:[~2021-08-18 6:06 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
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 ` Kees Cook [this message]
2021-09-01 13:46 ` [PATCH v2 07/63] skbuff: Switch structure bounds to struct_group() 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
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