lib/btree: fix possible NULL pointer dereference
kirjanov@gmail.com [Sat, 15 May 2010 16:32:34 +0000 (12:32 -0400)]
mempool_alloc() can return null in atomic case.

Signed-off-by: Denis Kirjanov <kirjanov@gmail.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/btree.c

index 41859a8..c9c6f03 100644 (file)
@@ -95,7 +95,8 @@ static unsigned long *btree_node_alloc(struct btree_head *head, gfp_t gfp)
        unsigned long *node;
 
        node = mempool_alloc(head->mempool, gfp);
-       memset(node, 0, NODESIZE);
+       if (likely(node))
+               memset(node, 0, NODESIZE);
        return node;
 }