2019-12-19 19:10:30

by Colin King

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

From: Colin Ian King <[email protected]>

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 <[email protected]>
---
drivers/gpu/drm/i915/display/intel_overlay.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

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);

--
2.24.0

2019-12-19 19:44:22

by Chris Wilson

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

Quoting Colin King (2019-12-19 19:09:16)
> From: Colin Ian King <[email protected]>
>
> 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 <[email protected]>

"D'oh"
Reviewed-by: Chris Wilson <[email protected]>
-Chris