[PATCH AUTOSEL 6.6 13/83] drm/amd/display: Skip updating link encoder for unknown eng_id

[Sasha Levin]

From: Alex Hung <alex.hung@xxxxxxx>

[ Upstream commit efabdce3db9f3d306084c8946983f3d895810a6b ]

This prevents accessing to negative index of link_encoders array.

This fixes an OVERRUN issue reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@xxxxxxx>
Acked-by: Tom Chung <chiahsuan.chung@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/link/link_factory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_factory.c b/drivers/gpu/drm/amd/display/dc/link/link_factory.c
index 2c366866f5700..6fc0cb918b9e5 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_factory.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_factory.c
@@ -408,7 +408,7 @@ static void link_destruct(struct dc_link *link)
 		 * the dynamic assignment of link encoders to streams. Virtual links
 		 * are not assigned encoder resources on creation.
 		 */
-		if (link->link_id.id != CONNECTOR_ID_VIRTUAL) {
+		if (link->link_id.id != CONNECTOR_ID_VIRTUAL && link->eng_id != ENGINE_ID_UNKNOWN) {
 			link->dc->res_pool->link_encoders[link->eng_id - ENGINE_ID_DIGA] = NULL;
 			link->dc->res_pool->dig_link_enc_count--;
 		}
-- 
2.43.0