commit 2271cf124a2763b7252887814a7fc8a844767e8f
author Axel Lin <axel.lin@ingics.com> Sun Mar 09 14:11:10 2014 +0800
committer Mark Brown <broonie@linaro.org> Mon Mar 10 16:06:45 2014 +0000
tree 2aa554da7a1af8000ac7c5c594123f1b6de0b5b7
parent 2aa237f4a1a72813f9684a0ce6e48288e75de479

spi: coldfire-qspi: Prevent NULL pointer dereference

If pdata->cs_control is NULL, we will hit NULL pointer dereference in
mcfqspi_cs_select() and mcfqspi_cs_deselect(). Thus add NULL test for
pdata->cs_control in probe().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-coldfire-qspi.c

diff --git a/drivers/spi/spi-coldfire-qspi.c b/drivers/spi/spi-coldfire-qspi.c
index 94d8175..6d78f96 100644
--- a/drivers/spi/spi-coldfire-qspi.c
+++ b/drivers/spi/spi-coldfire-qspi.c
@@ -133,13 +133,13 @@
 
 static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
 {
-	return (mcfqspi->cs_control && mcfqspi->cs_control->setup) ?
+	return (mcfqspi->cs_control->setup) ?
 		mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
 }
 
 static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
 {
-	if (mcfqspi->cs_control && mcfqspi->cs_control->teardown)
+	if (mcfqspi->cs_control->teardown)
 		mcfqspi->cs_control->teardown(mcfqspi->cs_control);
 }
 
@@ -372,6 +372,11 @@
 		return -ENOENT;
 	}
 
+	if (!pdata->cs_control) {
+		dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n");
+		return -EINVAL;
+	}
+
 	master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
 	if (master == NULL) {
 		dev_dbg(&pdev->dev, "spi_alloc_master failed\n");