This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: Add sanity checks for endpoint accesses
to the 4.5-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-add-sanity-checks-for-endpoint-accesses.patch
and it can be found in the queue-4.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 447d6275f0c21f6cc97a88b3a0c601436a4cdf2a Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Tue, 15 Mar 2016 15:20:58 +0100
Subject: ALSA: usb-audio: Add sanity checks for endpoint accesses
From: Takashi Iwai <tiwai@xxxxxxx>
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 <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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(+)
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -285,6 +285,8 @@ static int set_sample_rate_v1(struct snd
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 */
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -438,6 +438,9 @@ 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,
--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -1519,7 +1519,11 @@ static int snd_microii_spdif_default_get
/* use known values for that card: interface#1 altsetting#1 */
iface = usb_ifnum_to_if(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(chip->dev,
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -159,6 +159,8 @@ static int init_pitch_v1(struct snd_usb_
unsigned char data[1];
int err;
+ if (get_iface_desc(alts)->bNumEndpoints < 1)
+ return -EINVAL;
ep = get_endpoint(alts, 0)->bEndpointAddress;
data[0] = 1;
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-4.5/alsa-usb-audio-add-microsoft-hd-5001-to-quirks.patch
queue-4.5/alsa-usb-audio-fix-null-dereference-in-create_fixed_stream_quirk.patch
queue-4.5/alsa-usb-audio-minor-code-cleanup-in-create_fixed_stream_quirk.patch
queue-4.5/alsa-usb-audio-fix-double-free-in-error-paths-after-snd_usb_add_audio_stream-call.patch
queue-4.5/alsa-usb-audio-add-sanity-checks-for-endpoint-accesses.patch
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