From 3718909448116bf4411445468c58acc946379f92 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Tue, 27 Jan 2009 18:59:46 -0800 Subject: [PATCH] slub: fix per cpu kmem_cache_cpu array memory leak The per cpu array of kmem_cache_cpu structures accomodates NR_KMEM_CACHE_CPU such structs. When this array overflows and a struct is allocated by kmalloc(), it may have an address at the upper bound of this array. If this happens, it does not get freed and the per cpu kmem_cache_cpu_free pointer will be out of bounds after kmem_cache_destroy() or cpu offlining. Cc: Christoph Lameter Signed-off-by: David Rientjes Signed-off-by: Pekka Enberg --- mm/slub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 6392ae5cc6b1..bdc9abb08a23 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1996,7 +1996,7 @@ static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s, static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu) { if (c < per_cpu(kmem_cache_cpu, cpu) || - c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) { + c >= per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) { kfree(c); return; }