Commit Graph

31 Commits

Author SHA1 Message Date
Andrey Konovalov
51dcc81c28 kasan: adjust kasan_stack_oob for tag-based mode
Use OOB_TAG_OFF as access offset to land the access into the next granule.

Suggested-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: http://lkml.kernel.org/r/403b259f1de49a7a3694531c851ac28326a586a8.1596199677.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/3063ab1411e92bce36061a96e25b651212e70ba6.1596544734.git.andreyknvl@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:28 -07:00
Walter Wu
f33a01492a lib/test_kasan.c: fix KASAN unit tests for tag-based KASAN
We use tag-based KASAN, then KASAN unit tests don't detect out-of-bounds
memory access. They need to be fixed.

With tag-based KASAN, the state of each 16 aligned bytes of memory is
encoded in one shadow byte and the shadow value is tag of pointer, so
we need to read next shadow byte, the shadow value is not equal to tag
value of pointer, so that tag-based KASAN will detect out-of-bounds
memory access.

[walter-zh.wu@mediatek.com: use KASAN_SHADOW_SCALE_SIZE instead of 13]
  Link: http://lkml.kernel.org/r/20200708132524.11688-1-walter-zh.wu@mediatek.com

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Link: http://lkml.kernel.org/r/20200706115039.16750-1-walter-zh.wu@mediatek.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:28 -07:00
Walter Wu
387d6e4668 kasan: add tests for call_rcu stack recording
Test call_rcu() call stack recording and verify whether it correctly is
printed in KASAN report.

Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Link: http://lkml.kernel.org/r/20200601051045.1294-1-walter-zh.wu@mediatek.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:28 -07:00
Waiman Long
453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00
Daniel Axtens
adb72ae191 kasan: stop tests being eliminated as dead code with FORTIFY_SOURCE
Patch series "Fix some incompatibilites between KASAN and FORTIFY_SOURCE", v4.

3 KASAN self-tests fail on a kernel with both KASAN and FORTIFY_SOURCE:
memchr, memcmp and strlen.

When FORTIFY_SOURCE is on, a number of functions are replaced with
fortified versions, which attempt to check the sizes of the operands.
However, these functions often directly invoke __builtin_foo() once they
have performed the fortify check.  The compiler can detect that the
results of these functions are not used, and knows that they have no other
side effects, and so can eliminate them as dead code.

Why are only memchr, memcmp and strlen affected?
================================================

Of string and string-like functions, kasan_test tests:

 * strchr  ->  not affected, no fortified version
 * strrchr ->  likewise
 * strcmp  ->  likewise
 * strncmp ->  likewise

 * strnlen ->  not affected, the fortify source implementation calls the
               underlying strnlen implementation which is instrumented, not
               a builtin

 * strlen  ->  affected, the fortify souce implementation calls a __builtin
               version which the compiler can determine is dead.

 * memchr  ->  likewise
 * memcmp  ->  likewise

 * memset ->   not affected, the compiler knows that memset writes to its
	       first argument and therefore is not dead.

Why does this not affect the functions normally?
================================================

In string.h, these functions are not marked as __pure, so the compiler
cannot know that they do not have side effects.  If relevant functions are
marked as __pure in string.h, we see the following warnings and the
functions are elided:

lib/test_kasan.c: In function `kasan_memchr':
lib/test_kasan.c:606:2: warning: statement with no effect [-Wunused-value]
  memchr(ptr, '1', size + 1);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~
lib/test_kasan.c: In function `kasan_memcmp':
lib/test_kasan.c:622:2: warning: statement with no effect [-Wunused-value]
  memcmp(ptr, arr, size+1);
  ^~~~~~~~~~~~~~~~~~~~~~~~
lib/test_kasan.c: In function `kasan_strings':
lib/test_kasan.c:645:2: warning: statement with no effect [-Wunused-value]
  strchr(ptr, '1');
  ^~~~~~~~~~~~~~~~
...

This annotation would make sense to add and could be added at any point,
so the behaviour of test_kasan.c should change.

The fix
=======

Make all the functions that are pure write their results to a global,
which makes them live.  The strlen and memchr tests now pass.

The memcmp test still fails to trigger, which is addressed in the next
patch.

[dja@axtens.net: drop patch 3]
  Link: http://lkml.kernel.org/r/20200424145521.8203-2-dja@axtens.net
Fixes: 0c96350a2d ("lib/test_kasan.c: add tests for several string/memory API functions")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Link: http://lkml.kernel.org/r/20200423154503.5103-1-dja@axtens.net
Link: http://lkml.kernel.org/r/20200423154503.5103-2-dja@axtens.net
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:42 -07:00
Walter Wu
98f3b56fa6 kasan: add test for invalid size in memmove
Test negative size in memmove in order to verify whether it correctly get
KASAN report.

Casting negative numbers to size_t would indeed turn up as a large size_t,
so it will have out-of-bounds bug and be detected by KASAN.

[walter-zh.wu@mediatek.com: fix -Wstringop-overflow warning]
  Link: http://lkml.kernel.org/r/20200311134244.13016-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kernel test robot <lkp@intel.com>
Link: http://lkml.kernel.org/r/20191112065313.7060-1-walter-zh.wu@mediatek.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:30 -07:00
Gustavo A. R. Silva
3e21d9a501 lib/test_kasan.c: fix memory leak in kmalloc_oob_krealloc_more()
In case memory resources for _ptr2_ were allocated, release them before
return.

Notice that in case _ptr1_ happens to be NULL, krealloc() behaves
exactly like kmalloc().

Addresses-Coverity-ID: 1490594 ("Resource leak")
Link: http://lkml.kernel.org/r/20200123160115.GA4202@embeddedor
Fixes: 3f15801cdc ("lib: add kasan test module")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31 10:30:38 -08:00
Daniel Axtens
0651391693 kasan: add test for vmalloc
Test kasan vmalloc support by adding a new test to the module.

Link: http://lkml.kernel.org/r/20191031093909.9228-3-dja@axtens.net
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 12:59:05 -08:00
Mark Rutland
b92a953cb7 lib/test_kasan.c: add roundtrip tests
In several places we need to be able to operate on pointers which have
gone via a roundtrip:

	virt -> {phys,page} -> virt

With KASAN_SW_TAGS, we can't preserve the tag for SLUB objects, and the
{phys,page} -> virt conversion will use KASAN_TAG_KERNEL.

This patch adds tests to ensure that this works as expected, without
false positives which have recently been spotted [1,2] in testing.

[1] https://lore.kernel.org/linux-arm-kernel/20190819114420.2535-1-walter-zh.wu@mediatek.com/
[2] https://lore.kernel.org/linux-arm-kernel/20190819132347.GB9927@lakrids.cambridge.arm.com/

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20190821153927.28630-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:08 -07:00
Marco Elver
bb104ed785 lib/test_kasan: Add test for double-kzfree detection
Add a simple test that checks if double-kzfree is being detected
correctly.

Link: http://lkml.kernel.org/r/20190626142014.141844-4-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:42 -07:00
Marco Elver
19a33ca6c2 lib/test_kasan: add bitops tests
Patch series "Bitops instrumentation for KASAN", v5.

This patch (of 3):

This adds bitops tests to the test_kasan module.  In a follow-up patch,
support for bitops instrumentation will be added.

Link: http://lkml.kernel.org/r/20190613125950.197667-2-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:42 -07:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Andrey Ryabinin
7771bdbbfd kasan: remove use after scope bugs detection.
Use after scope bugs detector seems to be almost entirely useless for
the linux kernel.  It exists over two years, but I've seen only one
valid bug so far [1].  And the bug was fixed before it has been
reported.  There were some other use-after-scope reports, but they were
false-positives due to different reasons like incompatibility with
structleak plugin.

This feature significantly increases stack usage, especially with GCC <
9 version, and causes a 32K stack overflow.  It probably adds
performance penalty too.

Given all that, let's remove use-after-scope detector entirely.

While preparing this patch I've noticed that we mistakenly enable
use-after-scope detection for clang compiler regardless of
CONFIG_KASAN_EXTRA setting.  This is also fixed now.

[1] http://lkml.kernel.org/r/<20171129052106.rhgbjhhis53hkgfn@wfg-t540p.sh.intel.com>

Link: http://lkml.kernel.org/r/20190111185842.13978-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Will Deacon <will.deacon@arm.com>		[arm64]
Cc: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:13 -08:00
Andrey Ryabinin
0c96350a2d lib/test_kasan.c: add tests for several string/memory API functions
Arch code may have asm implementation of string/memory API functions
instead of using generic one from lib/string.c.  KASAN don't see memory
accesses in asm code, thus can miss many bugs.

E.g.  on ARM64 KASAN don't see bugs in memchr(), memcmp(), str[r]chr(),
str[n]cmp(), str[n]len().  Add tests for these functions to be sure that
we notice the problem on other architectures.

Link: http://lkml.kernel.org/r/20180920135631.23833-3-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:25:18 -07:00
Andrey Konovalov
91c93ed07f kasan: fix invalid-free test crashing the kernel
When an invalid-free is triggered by one of the KASAN tests, the object
doesn't actually get freed.  This later leads to a BUG failure in
kmem_cache_destroy that checks that there are no allocated objects in
the cache that is being destroyed.

Fix this by calling kmem_cache_free with the proper object address after
the call that triggers invalid-free.

Link: http://lkml.kernel.org/r/286eaefc0a6c3fa9b83b87e7d6dc0fbb5b5c9926.1519924383.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Chris Mason <clm@fb.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Cc: Kostya Serebryany <kcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:32 -07:00
Colin Ian King
48c2323954 kasan: remove redundant initialization of variable 'real_size'
Variable real_size is initialized with a value that is never read, it is
re-assigned a new value later on, hence the initialization is redundant
and can be removed.

Cleans up clang warning:

  lib/test_kasan.c:422:21: warning: Value stored to 'real_size' during its initialization is never read

Link: http://lkml.kernel.org/r/20180206144950.32457-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov
b1d5728939 kasan: detect invalid frees
Detect frees of pointers into middle of heap objects.

Link: http://lkml.kernel.org/r/cb569193190356beb018a03bb8d6fbae67e7adbc.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Dmitry Vyukov
47adccce3e kasan: detect invalid frees for large objects
Patch series "kasan: detect invalid frees".

KASAN detects double-frees, but does not detect invalid-frees (when a
pointer into a middle of heap object is passed to free).  We recently had
a very unpleasant case in crypto code which freed an inner object inside
of a heap allocation.  This left unnoticed during free, but totally
corrupted heap and later lead to a bunch of random crashes all over kernel
code.

Detect invalid frees.

This patch (of 5):

Detect frees of pointers into middle of large heap objects.

I dropped const from kasan_kfree_large() because it starts propagating
through a bunch of functions in kasan_report.c, slab/slub nearest_obj(),
all of their local variables, fixup_red_left(), etc.

Link: http://lkml.kernel.org/r/1b45b4fe1d20fc0de1329aab674c1dd973fee723.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:42 -08:00
Paul Lawrence
00a14294bb kasan: add tests for alloca poisoning
Link: http://lkml.kernel.org/r/20171204191735.132544-5-paullawrence@google.com
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:42 -08:00
Markus Elfring
dc2bf000a2 lib/test: delete five error messages for failed memory allocations
Omit extra messages for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/410a4c5a-4ee0-6fcc-969c-103d8e496b78@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:01 -08:00
Mark Rutland
b0845ce583 kasan: report only the first error by default
Disable kasan after the first report.  There are several reasons for
this:

 - Single bug quite often has multiple invalid memory accesses causing
   storm in the dmesg.

 - Write OOB access might corrupt metadata so the next report will print
   bogus alloc/free stacktraces.

 - Reports after the first easily could be not bugs by itself but just
   side effects of the first one.

Given that multiple reports usually only do harm, it makes sense to
disable kasan after the first one.  If user wants to see all the
reports, the boot-time parameter kasan_multi_shot must be used.

[aryabinin@virtuozzo.com: wrote changelog and doc, added missing include]
Link: http://lkml.kernel.org/r/20170323154416.30257-1-aryabinin@virtuozzo.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-31 17:13:30 -07:00
Greg Thelen
0386bf385d kasan: add memcg kmem_cache test
Make a kasan test which uses a SLAB_ACCOUNT slab cache.  If the test is
run within a non default memcg, then it uncovers the bug fixed by
"kasan: drain quarantine of memcg slab objects"[1].

If run without fix [1] it shows "Slab cache still has objects", and the
kmem_cache structure is leaked.
Here's an unpatched kernel test:

 $ dmesg -c > /dev/null
 $ mkdir /sys/fs/cgroup/memory/test
 $ echo $$ > /sys/fs/cgroup/memory/test/tasks
 $ modprobe test_kasan 2> /dev/null
 $ dmesg | grep -B1 still
 [ 123.456789] kasan test: memcg_accounted_kmem_cache allocate memcg accounted object
 [ 124.456789] kmem_cache_destroy test_cache: Slab cache still has objects

Kernels with fix [1] don't have the "Slab cache still has objects"
warning or the underlying leak.

The new test runs and passes in the default (root) memcg, though in the
root memcg it won't uncover the problem fixed by [1].

Link: http://lkml.kernel.org/r/1482257462-36948-2-git-send-email-gthelen@google.com
Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:56 -08:00
Dmitry Vyukov
828347f8f9 kasan: support use-after-scope detection
Gcc revision 241896 implements use-after-scope detection.  Will be
available in gcc 7.  Support it in KASAN.

Gcc emits 2 new callbacks to poison/unpoison large stack objects when
they go in/out of scope.  Implement the callbacks and add a test.

[dvyukov@google.com: v3]
  Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com
Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>	[4.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-30 16:32:52 -08:00
Andrey Ryabinin
eae08dcab8 kasan/tests: add tests for user memory access functions
Add some tests for the newly-added user memory access API.

Link: http://lkml.kernel.org/r/1462538722-1574-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
Alexander Potapenko
96fe805fb6 mm, kasan: add a ksize() test
Add a test that makes sure ksize() unpoisons the whole chunk.

Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Konstantin Serebryany <kcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
Alexander Potapenko
9dcadd381b kasan: test fix: warn if the UAF could not be detected in kmalloc_uaf2
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Alexander Potapenko
e6e8379c87 kasan: modify kmalloc_large_oob_right(), add kmalloc_pagealloc_oob_right()
This patchset implements SLAB support for KASAN

Unlike SLUB, SLAB doesn't store allocation/deallocation stacks for heap
objects, therefore we reimplement this feature in mm/kasan/stackdepot.c.
The intention is to ultimately switch SLUB to use this implementation as
well, which will save a lot of memory (right now SLUB bloats each object
by 256 bytes to store the allocation/deallocation stacks).

Also neither SLUB nor SLAB delay the reuse of freed memory chunks, which
is necessary for better detection of use-after-free errors.  We
introduce memory quarantine (mm/kasan/quarantine.c), which allows
delayed reuse of deallocated memory.

This patch (of 7):

Rename kmalloc_large_oob_right() to kmalloc_pagealloc_oob_right(), as
the test only checks the page allocator functionality.  Also reimplement
kmalloc_large_oob_right() so that the test allocates a large enough
chunk of memory that still does not trigger the page allocator fallback.

Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Wang Long
f523e737c0 lib: test_kasan: add some testcases
Add some out of bounds testcases to test_kasan module.

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Wang Long
6b4a35fc19 lib/test_kasan.c: make kmalloc_oob_krealloc_less more correctly
In kmalloc_oob_krealloc_less, I think it is better to test
the size2 boundary.

If we do not call krealloc, the access of position size1 will still cause
out-of-bounds and access of position size2 does not.  After call krealloc,
the access of position size2 cause out-of-bounds.  So using size2 is more
correct.

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10 13:29:01 -07:00
Wang Long
9789d8e0cf lib/test_kasan.c: fix a typo
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10 13:29:01 -07:00
Andrey Ryabinin
3f15801cdc lib: add kasan test module
This is a test module doing various nasty things like out of bounds
accesses, use after free.  It is useful for testing kernel debugging
features like kernel address sanitizer.

It mostly concentrates on testing of slab allocator, but we might want to
add more different stuff here in future (like stack/global variables out
of bounds accesses and so on).

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:41 -08:00