mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-27 21:03:32 +00:00
Code Issues Releases Wiki Activity

kasan: better identify bug types for tag-based modes

Browse source 
Identify the bug type for the tag-based modes based on the stack trace
entries found in the stack ring.

If a free entry is found first (meaning that it was added last), mark the
bug as use-after-free.  If an alloc entry is found first, mark the bug as
slab-out-of-bounds.  Otherwise, assign the common bug type.

This change returns the functionalify of the previously dropped
CONFIG_KASAN_TAGS_IDENTIFY.

Link: https://lkml.kernel.org/r/13ce7fa07d9d995caedd1439dfae4d51401842f2.1662411800.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2022-09-05 23:05:48 +02:00 committed by Andrew Morton
parent 80b92bfe3b
commit 1f538e1f2d
1 changed files with 21 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

25
mm/kasan/report_tags.c
View file

@ -10,7 +10,7 @@
extern struct kasan_stack_ring stack_ring;
static const char *get_bug_type(struct kasan_report_info *info)
static const char *get_common_bug_type(struct kasan_report_info *info)
{
/*
* If access_size is a negative number, then it has reason to be
@ -37,9 +37,8 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
bool is_free;
bool alloc_found = false, free_found = false;
info->bug_type = get_bug_type(info);
if (!info->cache || !info->object)
if (!info->cache || !info->object) {
info->bug_type = get_common_bug_type(info);
return;
}
@ -84,6 +83,13 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
info->free_track.pid = pid;
info->free_track.stack = stack;
free_found = true;
/*
* If a free entry is found first, the bug is likely
* a use-after-free.
*/
if (!info->bug_type)
info->bug_type = "use-after-free";
} else {
/* Second alloc of the same object. Give up. */
if (alloc_found)
@ -92,8 +98,19 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
info->alloc_track.pid = pid;
info->alloc_track.stack = stack;
alloc_found = true;
/*
* If an alloc entry is found first, the bug is likely
* an out-of-bounds.
*/
if (!info->bug_type)
info->bug_type = "slab-out-of-bounds";
}
}
write_unlock_irqrestore(&stack_ring.lock, flags);
/* Assign the common bug type if no entries were found. */
if (!info->bug_type)
info->bug_type = get_common_bug_type(info);
}