Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964826Ab2HIN5x (ORCPT ); Thu, 9 Aug 2012 09:57:53 -0400 Received: from smtp.ispras.ru ([83.149.198.202]:52403 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932262Ab2HIN5w (ORCPT ); Thu, 9 Aug 2012 09:57:52 -0400 From: Marina Makienko To: Tim Waugh Cc: Marina Makienko , "Grant R. Guenther" , linux-kernel@vger.kernel.org, ldv-project@ispras.ru Subject: [PATCH 01/13] block/paride: Potential null pointer dereference in pd_special_command() Date: Thu, 9 Aug 2012 17:54:05 +0400 Message-Id: <1344520446-13824-1-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: 1299 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/block/paride/pd.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c index 831e3ac..6e28910 100644 --- a/drivers/block/paride/pd.c +++ b/drivers/block/paride/pd.c @@ -723,6 +723,9 @@ static int pd_special_command(struct pd_unit *disk, rq = blk_get_request(disk->gd->queue, READ, __GFP_WAIT); + if (!rq) + return Fail; + rq->cmd_type = REQ_TYPE_SPECIAL; rq->special = func; -- 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/