Re: [PATCH] fix: drm/amd/display: dm_update_crtc_state: skip_modeset path leaves new_stream dangling, causing double release

[Mario Limonciello <mario.limonciello@amd.com>]

On 6/26/26 07:41, WenTao Liang wrote:
> The skip_modeset path calls dc_stream_release(new_stream) but does not
>    set new_stream to NULL. If a subsequent error (e.g., color management
>    failure) triggers goto fail, the fail label executes a second
>    dc_stream_release on the same pointer, causing a use-after-free or excess
>    put on the stream reference.
> 
> Cc: stable@vger.kernel.org
> Fixes: 3ce51649cdf2 ("drm/amdgpu/display: add quirk handling for stutter mode")
> Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>

The code change looks good to me, but this Fixes hash doesn't really 
make sense to me.

Are you sure about that?

I /think/ this is the correct hash:

Fixes: 9b690ef3c7042 ("drm/amd/display: Avoid full modeset when not 
required")

> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> 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 5fc5d5608506..acf0b01d6f62 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -11708,6 +11708,7 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
>   	/* Release extra reference */
>   	if (new_stream)
>   		dc_stream_release(new_stream);
> +	new_stream = NULL;
>   
>   	/*
>   	 * We want to do dc stream updates that do not require a