Re: [PATCH 6.1.y] drm/amd/display: fix NULL checks for adev->dm.dc in amdgpu_dm_fini()

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Dec 05, 2024 at 04:43:29PM +0800, jianqi.ren.cn@windriver.com wrote:
> From: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
> 
> Since 'adev->dm.dc' in amdgpu_dm_fini() might turn out to be NULL
> before the call to dc_enable_dmub_notifications(), check
> beforehand to ensure there will not be a possible NULL-ptr-deref
> there.
> 
> Also, since commit 1e88eb1b2c25 ("drm/amd/display: Drop
> CONFIG_DRM_AMD_DC_HDCP") there are two separate checks for NULL in
> 'adev->dm.dc' before dc_deinit_callbacks() and dc_dmub_srv_destroy().
> Clean up by combining them all under one 'if'.
> 
> Found by Linux Verification Center (linuxtesting.org) with static
> analysis tool SVACE.
> 
> Fixes: 81927e2808be ("drm/amd/display: Support for DMUB AUX")
> Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)

No upstream git id :(