Re: [PATCH] ALSA: usb-audio: fix sync-ep altsetting sanity check

[Takashi Iwai]

On Tue, 14 Jan 2020 09:39:53 +0100,
Johan Hovold wrote:
> 
> The altsetting sanity check in set_sync_ep_implicit_fb_quirk() was
> checking for there to be at least one altsetting but then went on to
> access the second one, which may not exist.
> 
> This could lead to random slab data being used to initialise the sync
> endpoint in snd_usb_add_endpoint().
> 
> Fixes: c75a8a7ae565 ("ALSA: snd-usb: add support for implicit feedback")
> Fixes: ca10a7ebdff1 ("ALSA: usb-audio: FT C400 sync playback EP to capture EP")
> Fixes: 5e35dc0338d8 ("ALSA: usb-audio: add implicit fb quirk for Behringer UFX1204")
> Fixes: 17f08b0d9aaf ("ALSA: usb-audio: add implicit fb quirk for Axe-Fx II")
> Fixes: 103e9625647a ("ALSA: usb-audio: simplify set_sync_ep_implicit_fb_quirk")
> Cc: stable <stable@xxxxxxxxxxxxxxx>     # 3.5
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>

Thanks, applied now.


Takashi