From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030220Ab2CMAdq (ORCPT ); Mon, 12 Mar 2012 20:33:46 -0400 Received: from mail.windriver.com ([147.11.1.11]:48752 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965121Ab2CMAYg (ORCPT ); Mon, 12 Mar 2012 20:24:36 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, James Bottomley , Paul Gortmaker Subject: [34-longterm 169/196] fix oops in scsi_run_queue() Date: Mon, 12 Mar 2012 20:21:22 -0400 Message-Id: <1331598109-31424-124-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.3 In-Reply-To: <1331598109-31424-1-git-send-email-paul.gortmaker@windriver.com> References: <1331597724-31358-1-git-send-email-paul.gortmaker@windriver.com> <1331598109-31424-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: James Bottomley ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit c055f5b2614b4f758ae6cc86733f31fa4c2c5844 upstream. The recent commit closing the race window in device teardown: commit 86cbfb5607d4b81b1a993ff689bbd2addd5d3a9b Author: James Bottomley Date: Fri Apr 22 10:39:59 2011 -0500 [SCSI] put stricter guards on queue dead checks is causing a potential NULL deref in scsi_run_queue() because the q->queuedata may already be NULL by the time this function is called. Since we shouldn't be running a queue that is being torn down, simply add a NULL check in scsi_run_queue() to forestall this. Tested-by: Jim Schutt Signed-off-by: James Bottomley Signed-off-by: Paul Gortmaker --- drivers/scsi/scsi_lib.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index c2a9e12..725f3cd 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -400,10 +400,15 @@ static inline int scsi_host_is_busy(struct Scsi_Host *shost) static void scsi_run_queue(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; - struct Scsi_Host *shost = sdev->host; + struct Scsi_Host *shost; LIST_HEAD(starved_list); unsigned long flags; + /* if the device is dead, sdev will be NULL, so no queue to run */ + if (!sdev) + return; + + shost = sdev->host; if (scsi_target(sdev)->single_lun) scsi_single_lun_run(sdev); -- 1.7.9.3