[patch] vmwgfx: information leak in vmw_execbuf_copy_fence_user()

[Dan Carpenter]

If ret is non-zero then we don't initialize the struct which leaks
stack information to user space.

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

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c 
b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index d4a1d8b..28e1c35 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -1070,6 +1070,8 @@ vmw_execbuf_copy_fence_user(struct vmw_private *dev_priv,
        if (user_fence_rep == NULL)
                return;

+       memset(&fence_rep, 0, sizeof(fence_rep));
+
        fence_rep.error = ret;
        if (ret == 0) {
                BUG_ON(fence == NULL);