Re: [PATCH] ALSA: seq: Fix UMP group 16 filtering

[Takashi Iwai]

On Wed, 06 May 2026 05:15:48 +0200,
Cássio Gabriel wrote:
> 
> The sequencer UAPI defines group_filter as an unsigned int bitmap.
> Bit 0 filters groupless messages and bits 1-16 filter UMP groups 1-16.
> 
> The internal snd_seq_client storage is only unsigned short, so bit 16
> is truncated when userspace sets the filter. The same truncation affects
> the automatic UMP client filter used to avoid delivery to inactive
> groups, so events for group 16 cannot be filtered.
> 
> Store the internal bitmap as unsigned int and keep both userspace-provided
> and automatically generated values limited to the defined UAPI bits.
> 
> Fixes: d2b706077792 ("ALSA: seq: Add UMP group filter")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>

A good catch!  Applied now.


thanks,

Takashi