From patchwork Thu Aug 9 13:55:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marina Makienko X-Patchwork-Id: 176106 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 174402C0098 for ; Fri, 10 Aug 2012 00:00:33 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932577Ab2HIOAH (ORCPT ); Thu, 9 Aug 2012 10:00:07 -0400 Received: from smtp.ispras.ru ([83.149.198.202]:52417 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932751Ab2HIN7R (ORCPT ); Thu, 9 Aug 2012 09:59:17 -0400 Received: from torvalds.intra.ispras.ru (unknown [83.149.198.253]) by smtp.ispras.ru (Postfix) with ESMTP id 5EC8F5D403C; Thu, 9 Aug 2012 17:23:50 +0400 (MSD) From: Marina Makienko To: "David S. Miller" Cc: Marina Makienko , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@ispras.ru Subject: [PATCH 10/13] ide: Potential null pointer dereference in ide_cd_queue_pc() Date: Thu, 9 Aug 2012 17:55:27 +0400 Message-Id: <1344520529-19164-8-git-send-email-makienko@ispras.ru> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1344520529-19164-1-git-send-email-makienko@ispras.ru> References: <1344520529-19164-1-git-send-email-makienko@ispras.ru> Sender: linux-ide-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org 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/ide/ide-cd.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 8126824..9dd575d 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -443,6 +443,9 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd, rq = blk_get_request(drive->queue, write, __GFP_WAIT); + if (!rq) + return -EIO; + memcpy(rq->cmd, cmd, BLK_MAX_CDB); rq->cmd_type = REQ_TYPE_ATA_PC; rq->sense = sense;