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| author | Sergey Senozhatsky <sergey.senozhatsky@gmail.com> | 2015-09-08 15:00:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 15:35:28 -0700 |
| commit | 3942d29918522ba6a393c19388301ec04df429cd (patch) | |
| tree | 7280b6114b6d794e306c7039b1dcd92852b8de01 /mm | |
| parent | 75e8f8b24cb0dc4951267d31f0a49e5ce2f345c4 (diff) | |
| download | lwn-3942d29918522ba6a393c19388301ec04df429cd.tar.gz lwn-3942d29918522ba6a393c19388301ec04df429cd.zip | |
mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()
kmem_cache_destroy() does not tolerate a NULL kmem_cache pointer argument
and performs a NULL-pointer dereference. This requires additional
attention and effort from developers/reviewers and forces all
kmem_cache_destroy() callers (200+ as of 4.1) to do a NULL check
if (cache)
kmem_cache_destroy(cache);
Or, otherwise, be invalid kmem_cache_destroy() users.
Tweak kmem_cache_destroy() and NULL-check the pointer there.
Proposed by Andrew Morton.
Link: https://lkml.org/lkml/2015/6/8/583
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Joe Perches <joe@perches.com>
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/slab_common.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index c26829fe4e37..bde04a699ab6 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -640,6 +640,9 @@ void kmem_cache_destroy(struct kmem_cache *s) bool need_rcu_barrier = false; bool busy = false; + if (unlikely(!s)) + return; + BUG_ON(!is_root_cache(s)); get_online_cpus(); |