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Message-Id: <a832bc33937d5cfd09a5370b42172f5a97114d78.1460380917.git.jslaby@suse.cz>
Date: Mon, 11 Apr 2016 15:23:01 +0200
From: Jiri Slaby <jslaby@...e.cz>
To: stable@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, Takashi Iwai <tiwai@...e.de>,
Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 3.12 59/98] ALSA: usb-audio: Add sanity checks for endpoint accesses
From: Takashi Iwai <tiwai@...e.de>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
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@...e.de>
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
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 86f80c60b21f..1329d7725196 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -283,6 +283,8 @@ 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 b0a0f2028319..c42a4c0e95da 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 ca2d07378807..ee4b3b901bf5 100644
--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -1372,7 +1372,11 @@ 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 98ca3540514f..1f498b1f88bd 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;
--
2.8.1
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