Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932764Ab2HIN5z (ORCPT ); Thu, 9 Aug 2012 09:57:55 -0400 Received: from smtp.ispras.ru ([83.149.198.202]:52406 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932262Ab2HIN5x (ORCPT ); Thu, 9 Aug 2012 09:57:53 -0400 From: Marina Makienko To: Peter Osterlund Cc: Marina Makienko , ldv-project@ispras.ru, linux-kernel@vger.kernel.org Subject: [PATCH 02/13] block: Potential null pointer dereference in pkt_generic_packet() Date: Thu, 9 Aug 2012 17:54:06 +0400 Message-Id: <1344520446-13824-2-git-send-email-makienko@ispras.ru> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1344520446-13824-1-git-send-email-makienko@ispras.ru> References: <1344520446-13824-1-git-send-email-makienko@ispras.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1406 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/pktcdvd.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index ba66e44..be477aa 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -743,6 +743,9 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command * rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ? WRITE : READ, __GFP_WAIT); + if (!rq) + return -EIO; + if (cgc->buflen) { if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT)) goto out; -- 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/