[patch 3/4] drm/qxl: array underflow in qxl_clientcap_ioctl()

[Dan Carpenter]

We check that "byte" isn't writing beyond the end of the array but we
also need to prevent array underflow.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c
index b2db482..552dc06 100644
--- a/drivers/gpu/drm/qxl/qxl_ioctl.c
+++ b/drivers/gpu/drm/qxl/qxl_ioctl.c
@@ -372,7 +372,7 @@ static int qxl_clientcap_ioctl(struct drm_device *dev, void *data,
 {
 	struct qxl_device *qdev = dev->dev_private;
 	struct drm_qxl_clientcap *param = data;
-	int byte, idx;
+	unsigned int byte, idx;
 
 	byte = param->index / 8;
 	idx = param->index % 8;