linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kees Cook <keescook@chromium.org>
To: linux-hardening@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Keith Packard <keithpac@amazon.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
	netdev@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
Subject: [PATCH 60/64] fortify: Work around Clang inlining bugs
Date: Tue, 27 Jul 2021 13:58:51 -0700	[thread overview]
Message-ID: <20210727205855.411487-61-keescook@chromium.org> (raw)
In-Reply-To: <20210727205855.411487-1-keescook@chromium.org>

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 | 33 +++++++++++++++++++++------------
 security/Kconfig               |  2 +-
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 718325331021..4afd42079d3b 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -38,10 +38,11 @@ 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,
+					 const 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)
@@ -112,12 +113,15 @@ __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)
@@ -329,7 +333,8 @@ __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);
 
@@ -340,7 +345,8 @@ __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);
@@ -356,7 +362,8 @@ __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);
 
@@ -368,7 +375,8 @@ __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);
 
@@ -392,7 +400,8 @@ __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 8f0e675e70a4..509ec61bc54b 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 !CONFIG_CC_IS_CLANG
+	depends on !CONFIG_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


  parent reply	other threads:[~2021-07-27 21:17 UTC|newest]

Thread overview: 158+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-27 20:57 [PATCH 00/64] Introduce strict memcpy() bounds checking Kees Cook
2021-07-27 20:57 ` [PATCH 01/64] media: omap3isp: Extract struct group for memcpy() region Kees Cook
2021-07-28  0:55   ` Gustavo A. R. Silva
2021-07-28  1:50     ` Kees Cook
2021-07-28  8:59   ` David Sterba
2021-07-28  9:14     ` Dan Carpenter
2021-07-28 21:37       ` Bart Van Assche
2021-07-28 21:37         ` David Sterba
2021-07-29  5:56           ` Greg Kroah-Hartman
2021-07-29  8:20             ` Dan Carpenter
2021-07-30  6:00               ` Kees Cook
2021-07-30  8:38                 ` David Sterba
2021-07-30  9:00                   ` Dan Carpenter
2021-07-30 16:44                     ` Kees Cook
2021-07-30 17:08                       ` Nick Desaulniers
2021-07-30 19:18                         ` Kees Cook
2021-07-27 20:57 ` [PATCH 02/64] mac80211: Use flex-array for radiotap header bitmap Kees Cook
2021-07-28  7:35   ` Dan Carpenter
2021-07-28  9:23     ` David Sterba
2021-07-28 21:54       ` Kees Cook
2021-07-29 10:45         ` David Sterba
2021-07-30  6:06           ` Kees Cook
2021-07-28 21:20     ` Kees Cook
2021-07-28 23:14     ` Kees Cook
2021-07-28 23:33     ` Kees Cook
2021-07-29  8:25       ` Dan Carpenter
2021-07-27 20:57 ` [PATCH 03/64] rpmsg: glink: Replace strncpy() with strscpy_pad() Kees Cook
2021-07-28  2:07   ` Gustavo A. R. Silva
2021-07-27 20:57 ` [PATCH 04/64] stddef: Introduce struct_group() helper macro Kees Cook
2021-07-28  2:32   ` Gustavo A. R. Silva
2021-07-28 10:54   ` Rasmus Villemoes
2021-07-28 21:59     ` Kees Cook
2021-07-30 22:19       ` Williams, Dan J
2021-07-31  2:59         ` Kees Cook
     [not found]           ` <CAKwiHFheDv2pwsm6Fa+-KnOFyvk7bfZQjb2BQ-CSwH61gxgVYg@mail.gmail.com>
2021-07-31 15:10             ` Kees Cook
2021-07-27 20:57 ` [PATCH 05/64] skbuff: Switch structure bounds to struct_group() Kees Cook
2021-07-28  3:50   ` Gustavo A. R. Silva
2021-07-27 20:57 ` [PATCH 06/64] bnxt_en: Use struct_group_attr() for memcpy() region Kees Cook
2021-07-28  1:03   ` Michael Chan
2021-07-28  4:45   ` Gustavo A. R. Silva
2021-07-27 20:57 ` [PATCH 07/64] staging: rtl8192e: Use struct_group() " Kees Cook
2021-07-27 22:30   ` Larry Finger
2021-07-28  5:45   ` Greg Kroah-Hartman
2021-07-27 20:57 ` [PATCH 08/64] staging: rtl8192u: " Kees Cook
2021-07-28  5:45   ` Greg Kroah-Hartman
2021-07-27 20:58 ` [PATCH 09/64] staging: rtl8723bs: Avoid field-overflowing memcpy() Kees Cook
2021-07-28  5:46   ` Greg Kroah-Hartman
2021-07-27 20:58 ` [PATCH 10/64] lib80211: Use struct_group() for memcpy() region Kees Cook
2021-07-28  5:52   ` Greg Kroah-Hartman
2021-08-13  8:04   ` Johannes Berg
2021-08-13 15:49     ` Kees Cook
2021-08-13 19:44       ` Johannes Berg
2021-07-27 20:58 ` [PATCH 11/64] net/mlx5e: Avoid field-overflowing memcpy() Kees Cook
2021-07-27 20:58 ` [PATCH 12/64] mwl8k: Use struct_group() for memcpy() region Kees Cook
2021-07-27 20:58 ` [PATCH 13/64] libertas: " Kees Cook
2021-07-27 20:58 ` [PATCH 14/64] libertas_tf: " Kees Cook
2021-07-27 20:58 ` [PATCH 15/64] ipw2x00: " Kees Cook
2021-07-28 18:55   ` Stanislav Yakovlev
2021-07-27 20:58 ` [PATCH 16/64] thermal: intel: int340x_thermal: " Kees Cook
2021-07-27 20:58 ` [PATCH 17/64] iommu/amd: " Kees Cook
2021-07-27 20:58 ` [PATCH 18/64] cxgb3: " Kees Cook
2021-07-27 20:58 ` [PATCH 19/64] ip: Use struct_group() for memcpy() regions Kees Cook
2021-07-28  5:55   ` Greg Kroah-Hartman
2021-07-28  6:14     ` Gustavo A. R. Silva
2021-07-28  6:19       ` Greg Kroah-Hartman
2021-07-28  6:31         ` Gustavo A. R. Silva
2021-07-28  6:37           ` Gustavo A. R. Silva
2021-07-28  6:41           ` Greg Kroah-Hartman
2021-07-28 21:01     ` Kees Cook
2021-07-29  1:59       ` Bart Van Assche
2021-07-27 20:58 ` [PATCH 20/64] intersil: Use struct_group() for memcpy() region Kees Cook
2021-07-27 20:58 ` [PATCH 21/64] cxgb4: " Kees Cook
2021-07-27 20:58 ` [PATCH 22/64] bnx2x: " Kees Cook
2021-07-27 20:58 ` [PATCH 23/64] drm/amd/pm: " Kees Cook
2021-07-30  2:07   ` Alex Deucher
2021-07-27 20:58 ` [PATCH 24/64] staging: wlan-ng: " Kees Cook
2021-07-28  5:45   ` Greg Kroah-Hartman
2021-07-27 20:58 ` [PATCH 25/64] drm/mga/mga_ioc32: " Kees Cook
2021-07-28  5:56   ` Greg Kroah-Hartman
2021-07-29 12:11     ` Daniel Vetter
2021-07-31  4:20       ` Kees Cook
2021-07-27 20:58 ` [PATCH 26/64] net/mlx5e: " Kees Cook
2021-07-27 20:58 ` [PATCH 27/64] HID: cp2112: " Kees Cook
2021-07-27 20:58 ` [PATCH 28/64] compiler_types.h: Remove __compiletime_object_size() Kees Cook
2021-07-27 20:58 ` [PATCH 29/64] lib/string: Move helper functions out of string.c Kees Cook
2021-07-27 20:58 ` [PATCH 30/64] fortify: Move remaining fortify helpers into fortify-string.h Kees Cook
2021-07-27 20:58 ` [PATCH 31/64] fortify: Explicitly disable Clang support Kees Cook
2021-07-27 21:18   ` Nathan Chancellor
2021-07-27 21:47     ` Kees Cook
2021-07-27 20:58 ` [PATCH 32/64] fortify: Add compile-time FORTIFY_SOURCE tests Kees Cook
2021-07-27 20:58 ` [PATCH 33/64] lib: Introduce CONFIG_TEST_MEMCPY Kees Cook
2021-07-27 23:31   ` Bart Van Assche
2021-07-27 23:33     ` Randy Dunlap
2021-07-28  1:30     ` Kees Cook
2021-07-27 20:58 ` [PATCH 34/64] fortify: Detect struct member overflows in memcpy() at compile-time Kees Cook
2021-07-27 22:43   ` Nick Desaulniers
2021-07-28  1:47     ` Kees Cook
2021-07-28 11:19   ` Rasmus Villemoes
2021-07-30  2:39     ` Kees Cook
2021-07-27 20:58 ` [PATCH 35/64] fortify: Detect struct member overflows in memmove() " Kees Cook
2021-07-27 20:58 ` [PATCH 36/64] scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp Kees Cook
2021-07-28  1:39   ` Martin K. Petersen
2021-07-28 18:57     ` Kees Cook
2021-07-29  3:35       ` Martin K. Petersen
2021-07-30 19:11         ` Tyrel Datwyler
2021-07-30 18:16     ` Tyrel Datwyler
2021-07-27 20:58 ` [PATCH 37/64] string.h: Introduce memset_after() for wiping trailing members/padding Kees Cook
2021-07-27 20:58 ` [PATCH 38/64] xfrm: Use memset_after() to clear padding Kees Cook
2021-07-27 20:58 ` [PATCH 39/64] mac80211: Use memset_after() to clear tx status Kees Cook
2021-07-31 15:55   ` Kees Cook
2021-08-13  7:40     ` Johannes Berg
2021-08-13 16:08       ` Kees Cook
2021-08-13 18:19         ` Johannes Berg
2021-08-13  7:41     ` Johannes Berg
2021-07-27 20:58 ` [PATCH 40/64] net: 802: Use memset_after() to clear struct fields Kees Cook
2021-07-27 20:58 ` [PATCH 41/64] net: dccp: Use memset_after() for TP zeroing Kees Cook
2021-07-27 20:58 ` [PATCH 42/64] net: qede: Use memset_after() for counters Kees Cook
2021-07-31 16:07   ` Kees Cook
2021-07-27 20:58 ` [PATCH 43/64] ath11k: Use memset_after() for clearing queue descriptors Kees Cook
2021-07-27 20:58 ` [PATCH 44/64] iw_cxgb4: Use memset_after() for cpl_t5_pass_accept_rpl Kees Cook
2021-07-27 20:58 ` [PATCH 45/64] intel_th: msu: Use memset_after() for clearing hw header Kees Cook
2021-07-27 20:58 ` [PATCH 46/64] IB/mthca: Use memset_after() for clearing mpt_entry Kees Cook
2021-07-27 20:58 ` [PATCH 47/64] btrfs: Use memset_after() to clear end of struct Kees Cook
2021-07-28  9:42   ` David Sterba
2021-07-28 21:56     ` Kees Cook
2021-07-29 10:33       ` David Sterba
2021-07-31 15:25         ` Kees Cook
2021-08-09 11:20           ` David Sterba
2021-07-27 20:58 ` [PATCH 48/64] drbd: Use struct_group() to zero algs Kees Cook
2021-07-28 21:45   ` Bart Van Assche
2021-07-30  2:31     ` Kees Cook
2021-07-30  2:57       ` Bart Van Assche
2021-07-30  9:25         ` Lars Ellenberg
2021-07-30 15:32       ` Nick Desaulniers
2021-07-27 20:58 ` [PATCH 49/64] cm4000_cs: Use struct_group() to zero struct cm4000_dev region Kees Cook
2021-07-28  5:48   ` Greg Kroah-Hartman
2021-07-27 20:58 ` [PATCH 50/64] KVM: x86: Use struct_group() to zero decode cache Kees Cook
2021-07-27 20:58 ` [PATCH 51/64] tracing: Use struct_group() to zero struct trace_iterator Kees Cook
2021-07-27 20:58 ` [PATCH 52/64] dm integrity: Use struct_group() to zero struct journal_sector Kees Cook
2021-07-27 20:58 ` [PATCH 53/64] HID: roccat: Use struct_group() to zero kone_mouse_event Kees Cook
2021-07-27 20:58 ` [PATCH 54/64] ipv6: Use struct_group() to zero rt6_info Kees Cook
2021-07-29 18:58   ` Jakub Kicinski
2021-07-31 15:01     ` Kees Cook
2021-07-27 20:58 ` [PATCH 55/64] RDMA/mlx5: Use struct_group() to zero struct mlx5_ib_mr Kees Cook
2021-07-27 20:58 ` [PATCH 56/64] ethtool: stats: Use struct_group() to clear all stats at once Kees Cook
2021-07-27 20:58 ` [PATCH 57/64] netfilter: conntrack: Use struct_group() to zero struct nf_conn Kees Cook
2021-07-27 20:58 ` [PATCH 58/64] powerpc: Split memset() to avoid multi-field overflow Kees Cook
2021-08-05 11:36   ` Michael Ellerman
2021-07-27 20:58 ` [PATCH 59/64] fortify: Detect struct member overflows in memset() at compile-time Kees Cook
2021-07-27 20:58 ` Kees Cook [this message]
2021-07-27 20:58 ` [PATCH 61/64] Makefile: Enable -Warray-bounds Kees Cook
2021-07-27 20:58 ` [PATCH 62/64] netlink: Avoid false-positive memcpy() warning Kees Cook
2021-07-28  5:49   ` Greg Kroah-Hartman
2021-07-28 11:24     ` Rasmus Villemoes
2021-07-30  1:39       ` Kees Cook
2021-07-30  1:41     ` Kees Cook
2021-07-27 20:58 ` [PATCH 63/64] iwlwifi: dbg_ini: Split memcpy() to avoid multi-field write Kees Cook
2021-07-27 20:58 ` [PATCH 64/64] fortify: Add run-time WARN for cross-field memcpy() Kees Cook

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210727205855.411487-61-keescook@chromium.org \
    --to=keescook@chromium.org \
    --cc=akpm@linux-foundation.org \
    --cc=clang-built-linux@googlegroups.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=gustavoars@kernel.org \
    --cc=keithpac@amazon.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-staging@lists.linux.dev \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --subject='Re: [PATCH 60/64] fortify: Work around Clang inlining bugs' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

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).