Patch "ALSA: usb-audio: Fix potential out-of-bound access at parsing SU" has been added to the 4.14-stable tree

Patch "ALSA: usb-audio: Fix potential out-of-bound access at parsing SU" has been added to the 4.14-stable tree

[gregkh]

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 4.14-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-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f658f17b5e0e339935dca23e77e0f3cad591926b Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
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 <tiwai@suse.de>

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.

Fixes: 99fc86450c43 ("ALSA: usb-mixer: parse descriptors with structs")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -2098,7 +2098,8 @@ 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 tiwai@suse.de are

queue-4.14/alsa-usb-audio-fix-potential-zero-division-at-parsing-fu.patch
queue-4.14/alsa-timer-remove-kernel-warning-at-compat-ioctl-error-paths.patch
queue-4.14/alsa-hda-add-raven-pci-id.patch
queue-4.14/alsa-usb-audio-add-sanity-checks-in-v2-clock-parsers.patch
queue-4.14/alsa-hda-fix-too-short-hdmi-dp-chmap-reporting.patch
queue-4.14/alsa-hda-realtek-fix-alc700-family-no-sound-issue.patch
queue-4.14/alsa-usb-audio-fix-potential-out-of-bound-access-at-parsing-su.patch
queue-4.14/alsa-pcm-update-tstamp-only-if-audio_tstamp-changed.patch
queue-4.14/alsa-hda-fix-yet-remaining-issue-with-vmaster-0db-initialization.patch
queue-4.14/alsa-hda-realtek-fix-alc275-no-sound-issue.patch
queue-4.14/alsa-usb-audio-add-sanity-checks-to-fe-parser.patch