From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754204Ab1G0Aiw (ORCPT ); Tue, 26 Jul 2011 20:38:52 -0400 Received: from mga01.intel.com ([192.55.52.88]:17764 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753907Ab1G0AfP (ORCPT ); Tue, 26 Jul 2011 20:35:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,272,1309762800"; d="scan'208";a="34855731" From: Andi Kleen References: <20110726534.972201586@firstfloor.org> In-Reply-To: <20110726534.972201586@firstfloor.org> To: cjb@laptop.org, gregkh@suse.de, ak@linux.intel.com, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] [23/98] mmc: sdhci: Check mrq != NULL in sdhci_tasklet_finish Message-Id: <20110727003515.6092B2403FF@tassilo.jf.intel.com> Date: Tue, 26 Jul 2011 17:35:15 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Chris Ball commit 0c9c99a765321104cc5f9c97f949382a9ba4927e upstream. It seems that under certain circumstances the sdhci_tasklet_finish() call can be entered with mrq set to NULL, causing the system to crash with a NULL pointer de-reference. Seen on S3C6410 system. Based on a patch by Dimitris Papastamos. Reported-by: Dimitris Papastamos Signed-off-by: Chris Ball Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- drivers/mmc/host/sdhci.c | 7 +++++++ 1 file changed, 7 insertions(+) Index: linux-2.6.35.y/drivers/mmc/host/sdhci.c =================================================================== --- linux-2.6.35.y.orig/drivers/mmc/host/sdhci.c +++ linux-2.6.35.y/drivers/mmc/host/sdhci.c @@ -1278,6 +1278,13 @@ static void sdhci_tasklet_finish(unsigne host = (struct sdhci_host*)param; + /* + * If this tasklet gets rescheduled while running, it will + * be run again afterwards but without any active request. + */ + if (!host->mrq) + return; + spin_lock_irqsave(&host->lock, flags); del_timer(&host->timer);