[next] drm/i915: fix uninitialized pointer reads on pointers to and from

Commit Message

Colin King Dec. 19, 2019, 7:09 p.m. UTC

From: Colin Ian King <[e-mail]>

Currently pointers to and from are not initialized and may contain
garbage values. This will cause uninitialized pointer reads in the
call to intel_frontbuffer_track and later checks to see if to and from
are null.  Fix this by ensuring to and from are initialized to NULL.

Addresses-Coverity: ("Uninitialised pointer read)"
Fixes: da42104f589d ("drm/i915: Hold reference to intel_frontbuffer as we track activity")
Signed-off-by: Colin Ian King <[e-mail]>
---
 drivers/gpu/drm/i915/display/intel_overlay.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Chris Wilson Dec. 19, 2019, 7:43 p.m. UTC | #1

Quoting Colin King (2019-12-19 19:09:16)
> From: Colin Ian King <[e-mail]>
> 
> Currently pointers to and from are not initialized and may contain
> garbage values. This will cause uninitialized pointer reads in the
> call to intel_frontbuffer_track and later checks to see if to and from
> are null.  Fix this by ensuring to and from are initialized to NULL.
> 
> Addresses-Coverity: ("Uninitialised pointer read)"
> Fixes: da42104f589d ("drm/i915: Hold reference to intel_frontbuffer as we track activity")
> Signed-off-by: Colin Ian King <[e-mail]>

"D'oh"
Reviewed-by: Chris Wilson <[e-mail]>
-Chris

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_overlay.c b/drivers/gpu/drm/i915/display/intel_overlay.c
index 6097594468a9..e869a3d86522 100644
--- a/drivers/gpu/drm/i915/display/intel_overlay.c
+++ b/drivers/gpu/drm/i915/display/intel_overlay.c
@@ -279,7 +279,7 @@  static void intel_overlay_flip_prepare(struct intel_overlay *overlay,
 				       struct i915_vma *vma)
 {
 	enum pipe pipe = overlay->crtc->pipe;
-	struct intel_frontbuffer *from, *to;
+	struct intel_frontbuffer *from = NULL, *to = NULL;
 
 	WARN_ON(overlay->old_vma);