From 52f1783ff4146344342422c1cd94fcb4ce39b6fe Mon Sep 17 00:00:00 2001
From: Igor Artemiev <Igor.A.Artemiev@mcst.ru>
Date: Mon, 3 Apr 2023 16:10:37 +0300
Subject: [PATCH] drm/amd/display: Fix potential null dereference
Git-commit: 52f1783ff4146344342422c1cd94fcb4ce39b6fe
Patch-mainline: v6.4-rc1
References: git-fixes
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@mcst.ru>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1441,7 +1441,8 @@ static void amdgpu_dm_fini(struct amdgpu
}
#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);