6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Allen Pan <allen.pan@amd.com>

[ Upstream commit 334b56cea5d9df5989be6cf1a5898114fa70ad98 ]

[How]
Check wheather state is NULL before releasing it.

[ Backport to 6.6.y: implemented the same guard in older
  dc_release_state() in dc.c rather than dc_state_release() in
  dc_state.c. ]

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Allen Pan <allen.pan@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Assisted-by: LLM
Signed-off-by: Artem Dinaburg <artem@trailofbits.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 50b860c07ae01..50df677d509dc 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -2302,7 +2302,8 @@ static void dc_state_free(struct kref *kref)
 
 void dc_release_state(struct dc_state *context)
 {
-	kref_put(&context->refcount, dc_state_free);
+	if (context != NULL)
+		kref_put(&context->refcount, dc_state_free);
 }
 
 bool dc_set_generic_gpio_for_stereo(bool enable,
-- 
2.53.0