Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030299Ab2HIN7g (ORCPT ); Thu, 9 Aug 2012 09:59:36 -0400 Received: from smtp.ispras.ru ([83.149.198.202]:52436 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030259Ab2HIN7d (ORCPT ); Thu, 9 Aug 2012 09:59:33 -0400 From: Marina Makienko To: Mike Anderson Cc: Marina Makienko , "James E.J. Bottomley" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@ispras.ru Subject: [PATCH 13/13] scsi: Potential null pointer dereference in scsi_eh_lock_door() Date: Thu, 9 Aug 2012 17:55:50 +0400 Message-Id: <1344520550-21134-1-git-send-email-makienko@ispras.ru> X-Mailer: git-send-email 1.7.7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1327 Lines: 39 The function blk_get_request() can return NULL in some cases. There are checks on it if function is called with argumetns one of which is GFP_ATOMIC/GFP_NOIO/etc. If system couldn't find request blk_get_request() return NULL. But if there is function call with argument __GFP_WAIT the system will wait until get request or the queue becomes dead. If something kills the queue, blk_get_request() return NULL and next operations will lead to errors. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Marina Makienko --- drivers/scsi/scsi_error.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 4a6381c..7dd67d4 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1624,6 +1624,9 @@ static void scsi_eh_lock_door(struct scsi_device *sdev) */ req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL); + if (!req) + return; + req->cmd[0] = ALLOW_MEDIUM_REMOVAL; req->cmd[1] = 0; req->cmd[2] = 0; -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/