Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966290AbcDLSIQ (ORCPT ); Tue, 12 Apr 2016 14:08:16 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49049 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966270AbcDLSIO (ORCPT ); Tue, 12 Apr 2016 14:08:14 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Takashi Iwai , Moritz Muehlenhoff , Luis Henriques Subject: [PATCH 3.16.y-ckt 05/17] ALSA: usb-audio: Add sanity checks for endpoint accesses Date: Tue, 12 Apr 2016 19:07:52 +0100 Message-Id: <1460484484-22395-6-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> References: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2982 Lines: 82 3.16.7-ckt27 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Takashi Iwai commit 447d6275f0c21f6cc97a88b3a0c601436a4cdf2a upstream. Add some sanity check codes before actually accessing the endpoint via get_endpoint() in order to avoid the invalid access through a malformed USB descriptor. Mostly just checking bNumEndpoints, but in one place (snd_microii_spdif_default_get()), the validity of iface and altsetting index is checked as well. Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=971125 Signed-off-by: Takashi Iwai Cc: Moritz Muehlenhoff [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques --- sound/usb/clock.c | 2 ++ sound/usb/endpoint.c | 3 +++ sound/usb/mixer_quirks.c | 4 ++++ sound/usb/pcm.c | 2 ++ 4 files changed, 11 insertions(+) diff --git a/sound/usb/clock.c b/sound/usb/clock.c index 03fed6611d9e..56216a23277f 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -285,6 +285,8 @@ static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, unsigned char data[3]; int err, crate; + if (get_iface_desc(alts)->bNumEndpoints < 1) + return -EINVAL; ep = get_endpoint(alts, 0)->bEndpointAddress; /* if endpoint doesn't have sampling rate control, bail out */ diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index 114e3e7ff511..e87436826b3b 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -410,6 +410,9 @@ exit_clear: * * New endpoints will be added to chip->ep_list and must be freed by * calling snd_usb_endpoint_free(). + * + * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that + * bNumEndpoints > 1 beforehand. */ struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, struct usb_host_interface *alts, diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index 614f33e63c3a..5bcf542b3a38 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -1456,7 +1456,11 @@ static int snd_microii_spdif_default_get(struct snd_kcontrol *kcontrol, /* use known values for that card: interface#1 altsetting#1 */ iface = usb_ifnum_to_if(mixer->chip->dev, 1); + if (!iface || iface->num_altsetting < 2) + return -EINVAL; alts = &iface->altsetting[1]; + if (get_iface_desc(alts)->bNumEndpoints < 1) + return -EINVAL; ep = get_endpoint(alts, 0)->bEndpointAddress; err = snd_usb_ctl_msg(mixer->chip->dev, diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index c62a1659106d..0bf61d4a1080 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -159,6 +159,8 @@ static int init_pitch_v1(struct snd_usb_audio *chip, int iface, unsigned char data[1]; int err; + if (get_iface_desc(alts)->bNumEndpoints < 1) + return -EINVAL; ep = get_endpoint(alts, 0)->bEndpointAddress; data[0] = 1;