Commit 447d6275 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: usb-audio: Add sanity checks for endpoint accesses 

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


Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 902eb7fd

sound/usb/clock.c

+2 −0
Original line number Diff line number Diff line
@@ -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 */

sound/usb/endpoint.c

+3 −0
Original line number Diff line number Diff line
@@ -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,

sound/usb/mixer_quirks.c

+4 −0
Original line number Diff line number Diff line
@@ -1519,7 +1519,11 @@ 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(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,

sound/usb/pcm.c

+2 −0
Original line number Diff line number Diff line
@@ -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;

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