[PATCH 08/12] FIX [1/2] slub: Do not dereference NULL pointer in node_match
From: Christoph Lameter 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 Cc: Steven Rostedt Cc: Pekka Enberg Signed-off-by: Thomas Gleixner [bigeasy@linutronix: replace page with c->page] Signed-off-by: Sebastian Andrzej Siewior --- mm/slub.c |2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 71de9b5..fbf6810 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2058,7 +2058,7 @@ static void flush_all(struct kmem_cache *s) static inline int node_match(struct kmem_cache_cpu *c, int node) { #ifdef CONFIG_NUMA - if (node != NUMA_NO_NODE && c->node != node) + if (!c->page || (node != NUMA_NO_NODE && c->node != node)) return 0; #endif return 1; -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 08/12] FIX [1/2] slub: Do not dereference NULL pointer in node_match
From: Christoph Lameter c...@linux.com 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 c...@linux.com Cc: Steven Rostedt rost...@goodmis.org Cc: Pekka Enberg penb...@kernel.org Signed-off-by: Thomas Gleixner t...@linutronix.de [bigeasy@linutronix: replace page with c-page] Signed-off-by: Sebastian Andrzej Siewior bige...@linutronix.de --- mm/slub.c |2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 71de9b5..fbf6810 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2058,7 +2058,7 @@ static void flush_all(struct kmem_cache *s) static inline int node_match(struct kmem_cache_cpu *c, int node) { #ifdef CONFIG_NUMA - if (node != NUMA_NO_NODE c-node != node) + if (!c-page || (node != NUMA_NO_NODE c-node != node)) return 0; #endif return 1; -- 1.7.10.4 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/