From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f172.google.com (mail-pd0-f172.google.com [209.85.192.172]) by kanga.kvack.org (Postfix) with ESMTP id 9AB686B0070 for ; Tue, 9 Jun 2015 08:05:58 -0400 (EDT) Received: by pdbnf5 with SMTP id nf5so13775999pdb.2 for ; Tue, 09 Jun 2015 05:05:58 -0700 (PDT) Received: from mail-pd0-x235.google.com (mail-pd0-x235.google.com. [2607:f8b0:400e:c02::235]) by mx.google.com with ESMTPS id nt2si8683216pbc.28.2015.06.09.05.05.57 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Jun 2015 05:05:57 -0700 (PDT) Received: by pdjn11 with SMTP id n11so13799930pdj.0 for ; Tue, 09 Jun 2015 05:05:57 -0700 (PDT) From: Sergey Senozhatsky Subject: [RFC][PATCH 3/5] mm/dmapool: allow NULL `pool' pointer in dma_pool_destroy() Date: Tue, 9 Jun 2015 21:04:51 +0900 Message-Id: <1433851493-23685-4-git-send-email-sergey.senozhatsky@gmail.com> In-Reply-To: <1433851493-23685-1-git-send-email-sergey.senozhatsky@gmail.com> References: <1433851493-23685-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Minchan Kim , Christoph Lameter , Pekka Enberg , Joonsoo Kim , Michal Hocko , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, sergey.senozhatsky.work@gmail.com, Sergey Senozhatsky 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. Signed-off-by: Sergey Senozhatsky Reported-by: Andrew Morton LKML-reference: https://lkml.org/lkml/2015/6/8/583 --- mm/dmapool.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/dmapool.c b/mm/dmapool.c index fd5fe43..5f2cffc 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); -- 2.4.3.368.g7974889 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org