From 44d7175da6ea10e353e69b586bb68bbfef89e403 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Tue, 8 Sep 2015 15:00:56 -0700 Subject: [PATCH] mm/dmapool: allow NULL `pool' pointer in dma_pool_destroy() dma_pool_destroy() does not tolerate a NULL dma_pool pointer argument and performs a NULL-pointer dereference. This requires additional attention and effort from developers/reviewers and forces all dma_pool_destroy() callers to do a NULL check if (pool) dma_pool_destroy(pool); Or, otherwise, be invalid dma_pool_destroy() users. Tweak dma_pool_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 Acked-by: David Rientjes Cc: Julia Lawall Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/dmapool.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/dmapool.c b/mm/dmapool.c index 59d10d16f0a5..4b657099111f 100644 --- a/mm/dmapool.c +++ b/mm/dmapool.c @@ -271,6 +271,9 @@ void dma_pool_destroy(struct dma_pool *pool) { bool empty = false; + if (unlikely(!pool)) + return; + mutex_lock(&pools_reg_lock); mutex_lock(&pools_lock); list_del(&pool->pools); -- 2.20.1