[PATCH] drm/amd/display: Skip inactive planes within ModeSupportAndSystemConfiguration

[guocai . he . cn]

From: Guocai He <guocai.he.cn@xxxxxxxxxxxxx>

commit a54f7e866cc73a4cb71b8b24bb568ba35c8969df upstream.

[Why]
Coverity reports Memory - illegal accesses.

[How]
Skip inactive planes.

Reviewed-by: Alex Hung <alex.hung@xxxxxxx>
Acked-by: Tom Chung <chiahsuan.chung@xxxxxxx>
Signed-off-by: Hersen Wu <hersenxs.wu@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>

Cherry-pick from a54f7e866cc73a4cb71b8b24bb568ba35c8969df
CVE-2024-46812

Signed-off-by: Guocai He <guocai.he.cn@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c b/drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c
index 0fad15020c74..b5ce2a8f4f1c 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c
@@ -892,6 +892,11 @@ void ModeSupportAndSystemConfiguration(struct display_mode_lib *mode_lib)
 
 	// Total Available Pipes Support Check
 	for (k = 0; k < mode_lib->vba.NumberOfActivePlanes; ++k) {
+        pipe_idx = get_pipe_idx(mode_lib, k);
+        if (pipe_idx == -1) {
+            ASSERT(0);
+            continue; // skip inactive planes
+        }
 		total_pipes += mode_lib->vba.DPPPerPlane[k];
 	}
 	ASSERT(total_pipes <= DC__NUM_DPP__MAX);
-- 
2.34.1