From 0c9c99a765321104cc5f9c97f949382a9ba4927e Mon Sep 17 00:00:00 2001 From: Chris Ball <cjb@laptop.org> Date: Wed, 27 Apr 2011 17:35:31 -0400 Subject: [PATCH] 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> --- drivers/mmc/host/sdhci.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index fd8f488df5fa..5d20661bc357 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -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); -- GitLab