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Date:   Tue, 6 Dec 2022 11:59:02 +0100
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Subject: Re: [PATCH] drm/amd/display: Added pointer check
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To:     Denis Arefev <arefev@swemel.ru>,
        Harry Wentland <harry.wentland@amd.com>
Cc:     Leo Li <sunpeng.li@amd.com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Aurabindo Pillai <aurabindo.pillai@amd.com>,
        Roman Li <roman.li@amd.com>,
        =?UTF-8?Q?Michel_D=c3=a4nzer?= <mdaenzer@redhat.com>,
        Fangzhi Zuo <Jerry.Zuo@amd.com>, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        lvc-project@linuxtesting.org, trufanov@swemel.ru, vfh@swemel.ru
References: <20221206104757.31512-1-arefev@swemel.ru>
From:   =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
In-Reply-To: <20221206104757.31512-1-arefev@swemel.ru>
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Am 06.12.22 um 11:47 schrieb Denis Arefev:
> Return value of a function 'dc_create_state' is
> dereferenced at amdgpu_dm.c:2027 without checking for null
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Denis Arefev <arefev@swemel.ru>
> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> 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 0f7749e9424d..529483997154 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -1960,7 +1960,9 @@ static int dm_resume(void *handle)
>   	dc_release_state(dm_state->context);
>   	dm_state->context = dc_create_state(dm->dc);
>   	/* TODO: Remove dc_state->dccg, use dc->dccg directly. */
> -	dc_resource_state_construct(dm->dc, dm_state->context);
> +	if (dm_state->context) {
> +		dc_resource_state_construct(dm->dc, dm_state->context);
> +	}

Single line statements shouldn't have an {} around them.

Apart from that I think error handling when dm_state->context can't be 
created would be more appropriate, but that's something our display team 
needs to look at.

Regards,
Christian.

>   
>   	/* Before powering on DC we need to re-initialize DMUB. */
>   	r = dm_dmub_hw_init(adev);