From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756193Ab2CMAXe (ORCPT ); Mon, 12 Mar 2012 20:23:34 -0400 Received: from mail.windriver.com ([147.11.1.11]:48196 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758922Ab2CMAX3 (ORCPT ); Mon, 12 Mar 2012 20:23:29 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Ben Dooks , Mark Brown , Chris Ball , Paul Gortmaker Subject: [34-longterm 108/196] mmc: sdhci: Check mrq->cmd in sdhci_tasklet_finish Date: Mon, 12 Mar 2012 20:20:21 -0400 Message-Id: <1331598109-31424-63-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.3 In-Reply-To: <1331598109-31424-1-git-send-email-paul.gortmaker@windriver.com> References: <1331597724-31358-1-git-send-email-paul.gortmaker@windriver.com> <1331598109-31424-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ben Dooks ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit b7b4d3426d2b5ecab21578eb20d8e456a1aace8f upstream. It seems that under certain circumstances that the sdhci_tasklet_finish() call can be entered with mrq->cmd set to NULL, causing the system to crash with a NULL pointer de-reference. Unable to handle kernel NULL pointer dereference at virtual address 00000000 PC is at sdhci_tasklet_finish+0x34/0xe8 LR is at sdhci_tasklet_finish+0x24/0xe8 Seen on S3C6410 system. Signed-off-by: Ben Dooks Signed-off-by: Mark Brown Signed-off-by: Chris Ball Signed-off-by: Paul Gortmaker --- drivers/mmc/host/sdhci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 9d4fdfa..6441e22 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1279,7 +1279,7 @@ static void sdhci_tasklet_finish(unsigned long param) * upon error conditions. */ if (!(host->flags & SDHCI_DEVICE_DEAD) && - (mrq->cmd->error || + ((mrq->cmd && mrq->cmd->error) || (mrq->data && (mrq->data->error || (mrq->data->stop && mrq->data->stop->error))) || (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST))) { -- 1.7.9.3