From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758262AbcIPIwR (ORCPT ); Fri, 16 Sep 2016 04:52:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40142 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753945AbcIPIvl (ORCPT ); Fri, 16 Sep 2016 04:51:41 -0400 From: Alexander Gordeev To: linux-kernel@vger.kernel.org Cc: Alexander Gordeev , Jens Axboe , linux-nvme@lists.infradead.org Subject: [PATCH 02/21] blk-mq: Fix a potential NULL pointer assignment to hctx tags Date: Fri, 16 Sep 2016 10:51:13 +0200 Message-Id: <68f41dd5411b38b4585d7ae92126e4c668e38390.1474014910.git.agordeev@redhat.com> In-Reply-To: References: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 16 Sep 2016 08:51:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If number of used hardware queues is dynamically decreased then tags corresponding to the newly unused queues are freed. If previously unused hardware queues are then reused again they will start referring the previously freed tags. CC: Jens Axboe CC: linux-nvme@lists.infradead.org Signed-off-by: Alexander Gordeev --- block/blk-mq.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 90e3fef..1cacf83 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2005,6 +2005,8 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, if (hctxs[i]) continue; + if (!set->tags[i]) + break; node = blk_mq_hw_queue_to_node(q->mq_map, i); hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), -- 1.8.3.1