From: Zhou Qingyang <zhou1615@umn.edu> stable inclusion from stable-v5.10.110 commit 19a7eba284790cfbba2945deb2363cf03ce41648 bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- 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 6c8f141103da..b65364695219 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6396,6 +6396,9 @@ 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++; } -- 2.20.1