From: Zhou Qingyang zhou1615@umn.edu
[ Upstream commit 588a70177df3b1777484267584ef38ab2ca899a2 ]
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: e7b07ceef2a6 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++ 1 file changed, 3 insertions(+)
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 8e4d863c7570..29f8b4bd5a76 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5013,6 +5013,9 @@ 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++; }