drm: Avoid oops in DRM_IOCTL_RM_DRAW if a bad handle is supplied.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Michel Dänzer <michel@tungstengraphics.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_drawable.c b/drivers/gpu/drm/drm_drawable.c
index 4a794d89942b..80be1cab62af 100644
--- a/drivers/gpu/drm/drm_drawable.c
+++ b/drivers/gpu/drm/drm_drawable.c
@@ -81,6 +81,10 @@ int drm_rmdraw(struct drm_device *dev, void *data, struct drm_file *file_priv)
         spin_lock_irqsave(&dev->drw_lock, irqflags);
 
         info = drm_get_drawable_info(dev, draw->handle);
+        if (info == NULL) {
+                spin_unlock_irqrestore(&dev->drw_lock, irqflags);
+                return -EINVAL;
+        }
         drm_free(info->rects, info->num_rects * sizeof(struct drm_clip_rect),
                         DRM_MEM_BUFS);
         drm_free(info, sizeof(struct drm_drawable_info), DRM_MEM_BUFS);