From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932885Ab1EFBAx (ORCPT ); Thu, 5 May 2011 21:00:53 -0400 Received: from kroah.org ([198.145.64.141]:36648 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932098Ab1EFAYc (ORCPT ); Thu, 5 May 2011 20:24:32 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Thu May 5 17:22:08 2011 Message-Id: <20110506002208.192222656@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Thu, 05 May 2011 17:20:16 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Chris Ball Subject: [031/143] mmc: sdhci: Check mrq != NULL in sdhci_tasklet_finish In-Reply-To: <20110506002311.GA15354@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us 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 --- drivers/mmc/host/sdhci.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1266,6 +1266,13 @@ 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);