From: Daniel Axtens <dja@axtens.net>
To: kernel-hardening@lists.openwall.com, akpm@linux-foundation.org,
keescook@chromium.org
Cc: linux-kernel@vger.kernel.org, Daniel Axtens <dja@axtens.net>
Subject: [PATCH v2 0/2] FORTIFY_SOURCE: detect intra-object overflow in string functions
Date: Mon, 20 Jan 2020 15:54:22 +1100 [thread overview]
Message-ID: <20200120045424.16147-1-dja@axtens.net> (raw)
When the fortify feature was first introduced in commit 6974f0c4555e
("include/linux/string.h: add the option of fortified string.h functions"),
Daniel Micay observed:
* It should be possible to optionally use __builtin_object_size(x, 1) for
some functions (C strings) to detect intra-object overflows (like
glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative
approach to avoid likely compatibility issues.
This patch set:
- converts a number of string functions to use __builtin_object_size(x, 1)
- adds LKDTM tests for both types of fortified function.
This change passes an allyesconfig on powerpc and x86, and an x86 kernel
built with it survives running with syz-stress from syzkaller, so it seems
safe so far.
Daniel Axtens (2):
string.h: detect intra-object overflow in fortified string functions
lkdtm: tests for FORTIFY_SOURCE
drivers/misc/lkdtm/bugs.c | 51 ++++++++++++++++++++++++++++++++++++++
drivers/misc/lkdtm/core.c | 2 ++
drivers/misc/lkdtm/lkdtm.h | 2 ++
include/linux/string.h | 27 ++++++++++++--------
4 files changed, 71 insertions(+), 11 deletions(-)
--
2.20.1
next reply other threads:[~2020-01-20 4:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-20 4:54 Daniel Axtens [this message]
2020-01-20 4:54 ` [PATCH v2 1/2] string.h: detect intra-object overflow in fortified string functions Daniel Axtens
2020-01-20 4:54 ` [PATCH v2 2/2] lkdtm: tests for FORTIFY_SOURCE Daniel Axtens
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