This is a note to let you know that I've just added the patch titled
drm/amd/display: Fix potential null dereference
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-fix-potential-null-dereference.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bf4050ed170769adc333319125e67f1317e057c5
Author: Igor Artemiev <Igor.A.Artemiev@xxxxxxx>
Date: Mon Apr 3 16:10:37 2023 +0300
drm/amd/display: Fix potential null dereference
[ Upstream commit 52f1783ff4146344342422c1cd94fcb4ce39b6fe ]
The adev->dm.dc pointer can be NULL and dereferenced in amdgpu_dm_fini()
without checking.
Add a NULL pointer check before calling dc_dmub_srv_destroy().
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 9a71c7d31734 ("drm/amd/display: Register DMUB service with DC")
Signed-off-by: Igor Artemiev <Igor.A.Artemiev@xxxxxxx>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 68c98e30fee71..1e0ddf7722cd4 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1707,7 +1707,8 @@ static void amdgpu_dm_fini(struct amdgpu_device *adev)
dc_deinit_callbacks(adev->dm.dc);
#endif
- dc_dmub_srv_destroy(&adev->dm.dc->ctx->dmub_srv);
+ if (adev->dm.dc)
+ dc_dmub_srv_destroy(&adev->dm.dc->ctx->dmub_srv);
if (dc_enable_dmub_notifications(adev->dm.dc)) {
kfree(adev->dm.dmub_notify);
