[ 012/102] DMA: OF: Check properties value before running be32_to_cpup() on it

[Greg Kroah-Hartman]

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

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

From: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

commit 9a188eb126aa7bf27077ee46fcb914898d6fc281 upstream.

In of_dma_controller_register() routine we are calling of_get_property() as an
parameter to be32_to_cpup(). In case the property doesn't exist we will get a
crash.

This patch changes this code to check if we got a valid property first and then
runs be32_to_cpup() on it.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Robert Richter <robert.richter@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/dma/of-dma.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -93,6 +93,7 @@ int of_dma_controller_register(struct de
 {
 	struct of_dma	*ofdma;
 	int		nbcells;
+	const __be32	*prop;
 
 	if (!np || !of_dma_xlate) {
 		pr_err("%s: not enough information provided\n", __func__);
@@ -103,8 +104,11 @@ int of_dma_controller_register(struct de
 	if (!ofdma)
 		return -ENOMEM;
 
-	nbcells = be32_to_cpup(of_get_property(np, "#dma-cells", NULL));
-	if (!nbcells) {
+	prop = of_get_property(np, "#dma-cells", NULL);
+	if (prop)
+		nbcells = be32_to_cpup(prop);
+
+	if (!prop || !nbcells) {
 		pr_err("%s: #dma-cells property is missing or invalid\n",
 		       __func__);
 		kfree(ofdma);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/