Re: [PATCH v3] intel_th: fix MSC output device reference leak

[Johan Hovold]

On Wed, Jul 15, 2026 at 03:08:51PM +0800, Guangshuo Li wrote:
> intel_th_output_open() looks up the output device with
> bus_find_device_by_devt(), which returns the device with a reference that
> must be dropped after use.
> 
> commit 95fc36a234da ("intel_th: fix device leak on output open()")
> attempted to drop the reference from intel_th_output_release(). However,
> a successful open replaces file->f_op with the output driver file
> operations before returning, so close runs the output driver release
> callback instead.
> 
> For MSC outputs, close runs intel_th_msc_release(), which only removes
> the per-file iterator and does not drop the device reference taken by
> intel_th_output_open(). Consequently, every successful MSC output open
> leaks one device reference.
> 
> Drop the device reference from intel_th_msc_release(), which is the
> release path actually used for MSC output files. Remove the now-unused
> intel_th_output_release() callback from intel_th_output_fops.
> 
> Fixes: 95fc36a234da ("intel_th: fix device leak on output open()")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
> ---
> v3:
>   - Remove the unused intel_th_output_release() callback as suggested by
>     Johan Hovold.
> 
> v2:
>   - Add Cc stable.
>   - No code changes.

Thanks for catching this.

Reviewed-by: Johan Hovold <johan@xxxxxxxxxx>

Johan