[PATCH 4.5 203/238] mmc: atmel-mci: Check pdata for NULL before dereferencing it at DMA config

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Brent Taylor <motobud@xxxxxxxxx>

commit 93c77d2999b09f2084b033ea6489915e0104ad9c upstream.

Using an at91sam9g20ek development board with DTS configuration may trigger
a kernel panic because of a NULL pointer dereference exception, while
configuring DMA. Let's fix this by adding a check for pdata before
dereferencing it.

Signed-off-by: Brent Taylor <motobud@xxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mmc/host/atmel-mci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2443,7 +2443,7 @@ static int atmci_configure_dma(struct at
 		struct mci_platform_data *pdata = host->pdev->dev.platform_data;
 		dma_cap_mask_t mask;
 
-		if (!pdata->dma_filter)
+		if (!pdata || !pdata->dma_filter)
 			return -ENODEV;
 
 		dma_cap_zero(mask);