mmc: sdhci: Check mrq != NULL in sdhci_tasklet_finish

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 <dp@opensource.wolfsonmicro.com>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Chris Ball 2011-04-27 17:35:31 -04:00
parent b7b4d3426d
commit 0c9c99a765

View file

@ -1334,6 +1334,13 @@ static void sdhci_tasklet_finish(unsigned long param)
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);