ALSA: ua101: Reject too-short USB descriptors

ALSA: ua101: Reject too-short USB descriptors

find_format_descriptor() walks the class-specific interface extras by
advancing with bLength. It rejects descriptors that extend past the
remaining buffer, but it does not reject descriptor lengths smaller than
a USB descriptor header.

Reject too-short descriptors before using bLength to advance the local
scan. This keeps the UA-101 parser robust against malformed descriptor
data and matches the usual USB descriptor walking rules.

Fixes: 63978ab3e3e9 ("sound: add Edirol UA-101 support")
Cc: stable@vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260519-alsa-ua101-desc-len-v1-1-4307d1a5e054@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>