spi: imx: Fix possible NULL pointer deref

transfer could be NULL in spi_imx_can_dma() when it's called from
spi_imx_setupxfer() with a NULL transfer. Test for a NULL pointer before
dereferencing it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index b79d70d..5076907 100644 (file)
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -211,11 +211,15 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
                         struct spi_transfer *transfer)
 {
        struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
-       unsigned int bpw = transfer->bits_per_word;
+       unsigned int bpw;
 
        if (!master->dma_rx)
                return false;
 
+       if (!transfer)
+               return false;
+
+       bpw = transfer->bits_per_word;
        if (!bpw)
                bpw = spi->bits_per_word;