From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120205220949.833935474@pcw.home.local> Date: Sun, 05 Feb 2012 23:09:58 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chris Ball , Greg KH Subject: [PATCH 09/91] mmc: sdhci: Check mrq != NULL in sdhci_tasklet_finish In-Reply-To: <0635750f5f06ed2ca212b91fcb5c4483@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.27-longterm review patch. If anyone has any objections, please let us know. ------------------ 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 files changed, 7 insertions(+), 0 deletions(-) Index: longterm-2.6.27/drivers/mmc/host/sdhci.c =================================================================== --- longterm-2.6.27.orig/drivers/mmc/host/sdhci.c 2012-02-05 22:34:36.053916156 +0100 +++ longterm-2.6.27/drivers/mmc/host/sdhci.c 2012-02-05 22:34:36.192916064 +0100 @@ -1165,6 +1165,13 @@ 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);