[PATCH AUTOSEL 6.10 013/121] drm/amd/display: Stop amdgpu_dm initialize when link nums greater than max_links

Sasha Levin
2024-08-01T00:09:43Z

From: Hersen Wu <hersenxs.wu@amd.com>

[ Upstream commit cf8b16857db702ceb8d52f9219a4613363e2b1cf ]

[Why]
Coverity report OVERRUN warning. There are
only max_links elements within dc->links. link
count could up to AMDGPU_DM_MAX_DISPLAY_INDEX 31.

[How]
Make sure link count less than max_links.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 9b440b26c6505..c893cf8f2d36e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4664,17 +4664,17 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
}
}

+ if (link_cnt > MAX_LINKS) {
+ DRM_ERROR(
+ "KMS: Cannot support more than %d display indexes\n",
+ MAX_LINKS);
+ goto fail;
+ }
+
/* loops over all connectors on the board */
for (i = 0; i < link_cnt; i++) {
struct dc_link *link = NULL;

- if (i > AMDGPU_DM_MAX_DISPLAY_INDEX) {
- DRM_ERROR(
- "KMS: Cannot support more than %d display indexes\n",
- AMDGPU_DM_MAX_DISPLAY_INDEX);
- continue;
- }
-
link = dc_get_link_at_index(dm->dc, i);

if (link->connector_signal == SIGNAL_TYPE_VIRTUAL) {
--
2.43.0