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| author | Christoph Lameter <cl@linux.com> | 2019-01-09 02:23:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-17 00:04:33 +0300 |
| commit | f928ca3917478d5f01e49c96f172dbe4c843d4c1 (patch) | |
| tree | ba176ab06c1c57c9c7f44b3d4b4315b256054b41 | |
| parent | 33c96bc68ff377064b18cd4bc821095b96a41e05 (diff) | |
| download | linux-f928ca3917478d5f01e49c96f172dbe4c843d4c1.tar.xz | |
slab: alien caches must not be initialized if the allocation of the alien cache failed
commit 09c2e76ed734a1d36470d257a778aaba28e86531 upstream.
Callers of __alloc_alien() check for NULL. We must do the same check in
__alloc_alien_cache to avoid NULL pointer dereferences on allocation
failures.
Link: http://lkml.kernel.org/r/010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@email.amazonses.com
Fixes: 49dfc304ba241 ("slab: use the lock on alien_cache, instead of the lock on array_cache")
Fixes: c8522a3a5832b ("Slab: introduce alloc_alien")
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: syzbot+d6ed4ec679652b4fd4e4@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/slab.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/slab.c b/mm/slab.c index d73c7a4820a4..fad6839e8eab 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -679,8 +679,10 @@ static struct alien_cache *__alloc_alien_cache(int node, int entries, struct alien_cache *alc = NULL; alc = kmalloc_node(memsize, gfp, node); - init_arraycache(&alc->ac, entries, batch); - spin_lock_init(&alc->lock); + if (alc) { + init_arraycache(&alc->ac, entries, batch); + spin_lock_init(&alc->lock); + } return alc; } |