[PATCH AUTOSEL 6.6 107/139] drm/amd/display: Check stream before comparing them

[Sasha Levin]

From: Alex Hung <alex.hung@xxxxxxx>

[ Upstream commit 35ff747c86767937ee1e0ca987545b7eed7a0810 ]

[WHAT & HOW]
amdgpu_dm can pass a null stream to dc_is_stream_unchanged. It is
necessary to check for null before dereferencing them.

This fixes 1 FORWARD_NULL issue reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@xxxxxxx>
Signed-off-by: Jerry Zuo <jerry.zuo@xxxxxxx>
Signed-off-by: Alex Hung <alex.hung@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 4b34bc9d4e4be..99fcd39bb15e0 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -2154,6 +2154,8 @@ static bool are_stream_backends_same(
 bool dc_is_stream_unchanged(
 	struct dc_stream_state *old_stream, struct dc_stream_state *stream)
 {
+	if (!old_stream || !stream)
+		return false;
 
 	if (!are_stream_backends_same(old_stream, stream))
 		return false;
-- 
2.43.0