mmc: atmel-mci: Check pdata for NULL before dereferencing it at DMA config

[ Upstream commit 93c77d2999b09f2084b033ea6489915e0104ad9c ]

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@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 576e96f6ccd0777c0cb2d52e17aba47d4aec4761..0c864eb21f58f3dd2f1b6a569f586be3003b48bb 100644 (file)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2286,7 +2286,7 @@ static int atmci_configure_dma(struct atmel_mci *host)
                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);