[PATCH 4.4 038/190] usb: dwc3: keystone: check return value

[Greg Kroah-Hartman]

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

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

From: Pan Bian <bianpan2016@xxxxxxx>


[ Upstream commit 018047a1dba7636e1f7fdae2cc290a528991d648 ]

Function devm_clk_get() returns an ERR_PTR when it fails. However, in
function kdwc3_probe(), its return value is not checked, which may
result in a bad memory access bug. This patch fixes the bug.

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/dwc3/dwc3-keystone.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/usb/dwc3/dwc3-keystone.c
+++ b/drivers/usb/dwc3/dwc3-keystone.c
@@ -112,6 +112,10 @@ static int kdwc3_probe(struct platform_d
 	dev->dma_mask = &kdwc3_dma_mask;
 
 	kdwc->clk = devm_clk_get(kdwc->dev, "usb");
+	if (IS_ERR(kdwc->clk)) {
+		dev_err(kdwc->dev, "unable to get usb clock\n");
+		return PTR_ERR(kdwc->clk);
+	}
 
 	error = clk_prepare_enable(kdwc->clk);
 	if (error < 0) {