Re: [PATCH 6.6] ALSA: usb-audio: Fix missing unlock at error path of maxpacksize check

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jan 30, 2026 at 06:04:44PM +0800, Wentao Guan wrote:
> I found that patch which in v6.12.60 should be applied in v6.6-stable tree.
> 
> From: Takashi Iwai <tiwai@suse.de>
> 
> The recent backport of the upstream commit 05a1fc5efdd8 ("ALSA:
> usb-audio: Fix potential overflow of PCM transfer buffer") on the
> older stable kernels like 6.12.y was broken since it doesn't consider
> the mutex unlock, where the upstream code manages with guard().
> In the older code, we still need an explicit unlock.
> 
> This is a fix that corrects the error path, applied only on old stable
> trees.
> 
> Reported-by: Pavel Machek <pavel@denx.de>
> Closes: https://lore.kernel.org/aSWtH0AZH5+aeb+a@duo.ucw.cz
> Fixes: 98e9d5e33bda ("ALSA: usb-audio: Fix potential overflow of PCM transfer buffer")
> Reviewed-by: Pavel Machek <pavel@denx.de>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> (cherry picked from commit fdf0dc82eb60091772ecea73cbc5a8fb7562fc45)
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
> ---
>  sound/usb/endpoint.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

This does not apply to the 6.6.y kernel tree :(

Please fix up and resend.

thanks,

greg k-h