Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933012AbZJIN6v (ORCPT ); Fri, 9 Oct 2009 09:58:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932672AbZJIN6t (ORCPT ); Fri, 9 Oct 2009 09:58:49 -0400 Received: from server1.wserver.cz ([82.113.45.157]:37649 "EHLO server1.wserver.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760864AbZJIN6q (ORCPT ); Fri, 9 Oct 2009 09:58:46 -0400 From: Jiri Slaby To: James.Bottomley@suse.de Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Jiri Slaby Subject: [PATCH -repost 4/4] SCSI: scsi_lib, fix potential NULL dereference Date: Fri, 9 Oct 2009 15:58:08 +0200 Message-Id: <1255096688-23399-4-git-send-email-jirislaby@gmail.com> X-Mailer: git-send-email 1.6.4.2 In-Reply-To: <1255096688-23399-1-git-send-email-jirislaby@gmail.com> References: <1255096688-23399-1-git-send-email-jirislaby@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 48 Stanse found a potential NULL dereference in scsi_kill_request. Instead of triggering BUG() in 'if (unlikely(cmd == NULL))' branch, the kernel will Oops earlier on cmd dereference. Move the dereferences after the if. Signed-off-by: Jiri Slaby Cc: James E.J. Bottomley --- drivers/scsi/scsi_lib.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 39b5858..53bdd25 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1359,9 +1359,9 @@ static int scsi_lld_busy(struct request_queue *q) static void scsi_kill_request(struct request *req, struct request_queue *q) { struct scsi_cmnd *cmd = req->special; - struct scsi_device *sdev = cmd->device; - struct scsi_target *starget = scsi_target(sdev); - struct Scsi_Host *shost = sdev->host; + struct scsi_device *sdev; + struct scsi_target *starget; + struct Scsi_Host *shost; blk_start_request(req); @@ -1371,6 +1371,9 @@ static void scsi_kill_request(struct request *req, struct request_queue *q) BUG(); } + sdev = cmd->device; + starget = scsi_target(sdev); + shost = sdev->host; scsi_init_cmd_errh(cmd); cmd->result = DID_NO_CONNECT << 16; atomic_inc(&cmd->device->iorequest_cnt); -- 1.6.4.2 -- 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/