From 54f9d645a5453d0bfece0c465d34aaf072ea99fa Mon Sep 17 00:00:00 2001 From: Jun Seo Date: Thu, 26 Feb 2026 10:08:20 +0900 Subject: [PATCH] ALSA: usb-audio: Use correct version for UAC3 header validation 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: Signed-off-by: Jun Seo Link: https://patch.msgid.link/20260226010820.36529-1-jun.seo.93@proton.me Signed-off-by: Takashi Iwai --- sound/usb/validate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/usb/validate.c b/sound/usb/validate.c index 4bb4893f6e74..f62b7cc041dc 100644 --- a/sound/usb/validate.c +++ b/sound/usb/validate.c @@ -281,7 +281,7 @@ static const struct usb_desc_validator audio_validators[] = { /* UAC_VERSION_2, UAC2_SAMPLE_RATE_CONVERTER: not implemented yet */ /* UAC3 */ - FIXED(UAC_VERSION_2, UAC_HEADER, struct uac3_ac_header_descriptor), + FIXED(UAC_VERSION_3, UAC_HEADER, struct uac3_ac_header_descriptor), FIXED(UAC_VERSION_3, UAC_INPUT_TERMINAL, struct uac3_input_terminal_descriptor), FIXED(UAC_VERSION_3, UAC_OUTPUT_TERMINAL,