diff options
| author | Feng Tang <feng.tang@intel.com> | 2022-10-21 11:24:04 +0800 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2022-11-10 16:27:46 +0100 |
| commit | 5d1ba31087627423dfb2bd87badd62361701997b (patch) | |
| tree | 30115b55a761164a8b64a1e1fdbdef8842ef8ada /mm/slub.c | |
| parent | 9ce67395f5a0cdec6ce152d26bfda13b98b25c01 (diff) | |
mm: kasan: Extend kasan_metadata_size() to also cover in-object size
When kasan is enabled for slab/slub, it may save kasan' free_meta
data in the former part of slab object data area in slab object's
free path, which works fine.
There is ongoing effort to extend slub's debug function which will
redzone the latter part of kmalloc object area, and when both of
the debug are enabled, there is possible conflict, especially when
the kmalloc object has small size, as caught by 0Day bot [1].
To solve it, slub code needs to know the in-object kasan's meta
data size. Currently, there is existing kasan_metadata_size()
which returns the kasan's metadata size inside slub's metadata
area, so extend it to also cover the in-object meta size by
adding a boolean flag 'in_object'.
There is no functional change to existing code logic.
[1]. https://lore.kernel.org/lkml/YuYm3dWwpZwH58Hu@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/slub.c b/mm/slub.c index ecc44067625c..b81a4bba1b73 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -910,7 +910,7 @@ static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p) if (slub_debug_orig_size(s)) off += sizeof(unsigned int); - off += kasan_metadata_size(s); + off += kasan_metadata_size(s, false); if (off != size_from_object(s)) /* Beginning of the filler is the free pointer */ @@ -1070,7 +1070,7 @@ static int check_pad_bytes(struct kmem_cache *s, struct slab *slab, u8 *p) off += sizeof(unsigned int); } - off += kasan_metadata_size(s); + off += kasan_metadata_size(s, false); if (size_from_object(s) == off) return 1; |