From: Ben Dooks <ben-linux@fluff.org>
Date: Wed, 27 Apr 2011 13:24:19 +0000 (+0100)
Subject: mmc: sdhci: Check mrq->cmd in sdhci_tasklet_finish
X-Git-Tag: firefly_0821_release~10186^2~138
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3de4df1efd0d953c016e3a3bca0719c04ceb4a51;p=firefly-linux-kernel-4.4.55.git
mmc: sdhci: Check mrq->cmd in sdhci_tasklet_finish
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 <ben-linux@fluff.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c279fbc4c2e5..0b388cc3a242 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1277,7 +1277,7 @@ 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))) {