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

ALSA: usb-audio: Add sanity checks to FE parser

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: alsa-usb-audio-add-sanity-checks-to-fe-parser.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 stable@vger.kernel.org know about it.

From d937cd6790a2bef2d07b500487646bd794c039bb Mon Sep 17 00:00:00 2001

From: Takashi Iwai tiwai@suse.de Date: Tue, 21 Nov 2017 16:55:51 +0100 Subject: ALSA: usb-audio: Add sanity checks to FE parser

From: Takashi Iwai tiwai@suse.de

commit d937cd6790a2bef2d07b500487646bd794c039bb upstream.

When the usb-audio descriptor contains the malformed feature unit description with a too short length, the driver may access out-of-bounds. Add a sanity check of the header size at the beginning of parse_audio_feature_unit().

Fixes: 23caaf19b11e ("ALSA: usb-mixer: Add support for Audio Class v2.0") Reported-by: Andrey Konovalov andreyknvl@google.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- sound/usb/mixer.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)

--- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1463,6 +1463,12 @@ static int parse_audio_feature_unit(stru __u8 *bmaControls;

if (state->mixer->protocol == UAC_VERSION_1) { + if (hdr->bLength < 7) { + usb_audio_err(state->chip, + "unit %u: invalid UAC_FEATURE_UNIT descriptor\n", + unitid); + return -EINVAL; + } csize = hdr->bControlSize; if (!csize) { usb_audio_dbg(state->chip, @@ -1480,6 +1486,12 @@ static int parse_audio_feature_unit(stru } } else { struct uac2_feature_unit_descriptor *ftr = _ftr; + if (hdr->bLength < 6) { + usb_audio_err(state->chip, + "unit %u: invalid UAC_FEATURE_UNIT descriptor\n", + unitid); + return -EINVAL; + } csize = 4; channels = (hdr->bLength - 6) / 4 - 1; bmaControls = ftr->bmaControls;

Patches currently in stable-queue which might be from tiwai@suse.de 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