Patch "ALSA: usb-audio: Fix potential out-of-bound access at parsing SU" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

ALSA: usb-audio: Fix potential out-of-bound access at parsing SU

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
alsa-usb-audio-fix-potential-out-of-bound-access-at-parsing-su.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Takashi Iwai <[email protected]>
Date: Tue, 21 Nov 2017 17:00:32 +0100
Subject: ALSA: usb-audio: Fix potential out-of-bound access at parsing SU

From: Takashi Iwai <[email protected]>

commit f658f17b5e0e339935dca23e77e0f3cad591926b upstream.

The usb-audio driver may trigger an out-of-bound access at parsing a malformed selector unit, as it checks the header length only after evaluating bNrInPins field, which can be already above the given length. Fix it by adding the length check beforehand.

---
 sound/usb/mixer.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -2092,7 +2092,8 @@ static int parse_audio_selector_unit(str
 	const struct usbmix_name_map *map;
 	char **namelist;
 
-	if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
+	if (desc->bLength < 5 || !desc->bNrInPins ||
+	    desc->bLength < 5 + desc->bNrInPins) {
 		usb_audio_err(state->chip,
 			"invalid SELECTOR UNIT descriptor %d\n", unitid);
 		return -EINVAL;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/alsa-usb-audio-fix-potential-zero-division-at-parsing-fu.patch queue-4.9/alsa-timer-remove-kernel-warning-at-compat-ioctl-error-paths.patch queue-4.9/alsa-hda-add-raven-pci-id.patch queue-4.9/alsa-usb-audio-add-sanity-checks-in-v2-clock-parsers.patch queue-4.9/alsa-hda-fix-too-short-hdmi-dp-chmap-reporting.patch queue-4.9/alsa-hda-realtek-fix-alc700-family-no-sound-issue.patch queue-4.9/alsa-usb-audio-fix-potential-out-of-bound-access-at-parsing-su.patch queue-4.9/alsa-pcm-update-tstamp-only-if-audio_tstamp-changed.patch queue-4.9/alsa-usb-audio-add-sanity-checks-to-fe-parser.patch