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| author | Alexander Potapenko <glider@google.com> | 2021-05-23 03:41:56 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-23 04:09:07 +0300 |
| commit | f70b00496f2a0669fdb19a783e613bdbdedcf901 (patch) | |
| tree | c8e67f9b8062c3ab2dccc36a2e7f0c6f2b0104b8 /mm | |
| parent | 4d1cd3b2c5c1c32826454de3a18c6183238d47ed (diff) | |
| download | linux-f70b00496f2a0669fdb19a783e613bdbdedcf901.tar.xz | |
kasan: slab: always reset the tag in get_freepointer_safe()
With CONFIG_DEBUG_PAGEALLOC enabled, the kernel should also untag the
object pointer, as done in get_freepointer().
Failing to do so reportedly leads to SLUB freelist corruptions that
manifest as boot-time crashes.
Link: https://lkml.kernel.org/r/20210514072228.534418-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Elliot Berman <eberman@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slub.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/slub.c b/mm/slub.c index 438fa8d4c970..3f96e099817a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -301,6 +301,7 @@ static inline void *get_freepointer_safe(struct kmem_cache *s, void *object) if (!debug_pagealloc_enabled_static()) return get_freepointer(s, object); + object = kasan_reset_tag(object); freepointer_addr = (unsigned long)object + s->offset; copy_from_kernel_nofault(&p, (void **)freepointer_addr, sizeof(p)); return freelist_ptr(s, p, freepointer_addr); |