[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;