Re: [PATCH] ALSA: usb-audio: Use correct version for UAC3 header validation

[Takashi Iwai]

On Thu, 26 Feb 2026 02:08:20 +0100,
Jun Seo wrote:
> 
> The entry of the validators table for UAC3 AC header descriptor is
> defined with the wrong protocol version UAC_VERSION_2, while it should
> have been UAC_VERSION_3.  This results in the validator never matching
> for actual UAC3 devices (protocol == UAC_VERSION_3), causing their
> header descriptors to bypass validation entirely.  A malicious USB
> device presenting a truncated UAC3 header could exploit this to cause
> out-of-bounds reads when the driver later accesses unvalidated
> descriptor fields.
> 
> The bug was introduced in the same commit as the recently fixed UAC3
> feature unit sub-type typo, and appears to be from the same copy-paste
> error when the UAC3 section was created from the UAC2 section.
> 
> Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Jun Seo <jun.seo.93@xxxxxxxxx>

Thanks, applied now.


Takashi