mm/mempool: allow NULL `pool' pointer in mempool_destroy()
mempool_destroy() does not tolerate a NULL mempool_t pointer argument and
performs a NULL-pointer dereference. This requires additional attention
and effort from developers/reviewers and forces all mempool_destroy()
callers to do a NULL check
if (pool)
mempool_destroy(pool);
Or, otherwise, be invalid mempool_destroy() users.
Tweak mempool_destroy() and NULL-check the pointer there.
Proposed by Andrew Morton.
Link: https://lkml.org/lkml/2015/6/8/583
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mempool.c b/mm/mempool.c
index 2cc08de..4c533bc 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -150,6 +150,9 @@
*/
void mempool_destroy(mempool_t *pool)
{
+ if (unlikely(!pool))
+ return;
+
while (pool->curr_nr) {
void *element = remove_element(pool);
pool->free(element, pool->pool_data);