This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: Validate MS endpoint descriptors
to the 4.4-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-validate-ms-endpoint-descriptors.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e84749a78dc82bc545f12ce009e3dbcc2c5a8a91 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Mon, 10 May 2021 17:06:59 +0200
Subject: ALSA: usb-audio: Validate MS endpoint descriptors
From: Takashi Iwai <tiwai@xxxxxxx>
commit e84749a78dc82bc545f12ce009e3dbcc2c5a8a91 upstream.
snd_usbmidi_get_ms_info() may access beyond the border when a
malformed descriptor is passed. This patch adds the sanity checks of
the given MS endpoint descriptors, and skips invalid ones.
Reported-by: syzbot+6bb23a5d5548b93c94aa@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210510150659.17710-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/midi.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -1865,8 +1865,12 @@ static int snd_usbmidi_get_ms_info(struc
ms_ep = find_usb_ms_endpoint_descriptor(hostep);
if (!ms_ep)
continue;
+ if (ms_ep->bLength <= sizeof(*ms_ep))
+ continue;
if (ms_ep->bNumEmbMIDIJack > 0x10)
continue;
+ if (ms_ep->bLength < sizeof(*ms_ep) + ms_ep->bNumEmbMIDIJack)
+ continue;
if (usb_endpoint_dir_out(ep)) {
if (endpoints[epidx].out_ep) {
if (++epidx >= MIDI_MAX_ENDPOINTS) {
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-4.4/alsa-bebob-oxfw-fix-kconfig-entry-for-mackie-d.2-pro.patch
queue-4.4/alsa-usb-audio-validate-ms-endpoint-descriptors.patch
queue-4.4/revert-alsa-sb8-add-a-check-for-request_region.patch
