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| author | Christoph Lameter <cl@linux.com> | 2013-01-23 21:45:47 +0000 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2013-04-05 14:23:05 +0300 |
| commit | 4d7868e6475d478172581828021bd8a356726679 (patch) | |
| tree | f8144ea29586a3f50278936c4a8a5ab02a61636c /mm/slub.c | |
| parent | 338b2642290ef3193229ece8cfc776ac4fe8869d (diff) | |
| download | lwn-4d7868e6475d478172581828021bd8a356726679.tar.gz lwn-4d7868e6475d478172581828021bd8a356726679.zip | |
slub: Do not dereference NULL pointer in node_match
The variables accessed in slab_alloc are volatile and therefore
the page pointer passed to node_match can be NULL. The processing
of data in slab_alloc is tentative until either the cmpxhchg
succeeds or the __slab_alloc slowpath is invoked. Both are
able to perform the same allocation from the freelist.
Check for the NULL pointer in node_match.
A false positive will lead to a retry of the loop in __slab_alloc.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c index 21b3f004f614..8b1b99d399cb 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2042,7 +2042,7 @@ static void flush_all(struct kmem_cache *s) static inline int node_match(struct page *page, int node) { #ifdef CONFIG_NUMA - if (node != NUMA_NO_NODE && page_to_nid(page) != node) + if (!page || (node != NUMA_NO_NODE && page_to_nid(page) != node)) return 0; #endif return 1; |