drm/amd/display: Fix a NULL pointer dereference in amdgpu_dm_connector_add_common_modes()

In amdgpu_dm_connector_add_common_modes(), amdgpu_dm_create_common_mode()
is assigned to mode and is passed to drm_mode_probed_add() directly after
that. drm_mode_probed_add() passes &mode->head to list_add_tail(), and
there is a dereference of it in list_add_tail() without recoveries, which
could lead to NULL pointer dereference on failure of
amdgpu_dm_create_common_mode().

Fix this by adding a NULL check of mode.

This bug was found by a static analyzer.

Builds with 'make allyesconfig' show no new warnings,
and our static analyzer no longer warns about this code.

Fixes: e7b07ceef2 ("drm/amd/display: Merge amdgpu_dm_types and amdgpu_dm")
Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Zhou Qingyang 2022-01-25 00:57:29 +08:00 committed by Alex Deucher
parent 153a9529d7
commit 588a70177d

View file

@ -8138,6 +8138,9 @@ static void amdgpu_dm_connector_add_common_modes(struct drm_encoder *encoder,
mode = amdgpu_dm_create_common_mode(encoder,
common_modes[i].name, common_modes[i].w,
common_modes[i].h);
if (!mode)
continue;
drm_mode_probed_add(connector, mode);
amdgpu_dm_connector->num_modes++;
}