[PATCH] zsmalloc: fix a null pointer dereference in destroy_handle_cache()

From: Sergey Senozhatsky
Date: Fri Jun 05 2015 - 07:12:11 EST


zs_destroy_pool()->destroy_handle_cache() invoked from
zs_create_pool() can pass a NULL ->handle_cachep pointer
to kmem_cache_destroy(), which will dereference it.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
---
mm/zsmalloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 33d5126..c766240 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -285,7 +285,8 @@ static int create_handle_cache(struct zs_pool *pool)

static void destroy_handle_cache(struct zs_pool *pool)
{
- kmem_cache_destroy(pool->handle_cachep);
+ if (pool->handle_cachep)
+ kmem_cache_destroy(pool->handle_cachep);
}

static unsigned long alloc_handle(struct zs_pool *pool)
--
2.4.2.387.gf86f31a

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