From b909df18ce2a998afef81d58bbd1a05dc0788c40 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Sevens?= <bsevens@google.com>
Date: Wed, 20 Nov 2024 12:41:44 +0000
Subject: [PATCH] ALSA: usb-audio: Fix potential out-of-bound accesses for
Extigy and Mbox devices
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A bogus device can provide a bNumConfigurations value that exceeds the
initial value used in usb_get_configuration for allocating dev->config.
This can lead to out-of-bounds accesses later, e.g. in
usb_destroy_configuration.
Signed-off-by: Benoît Sevens <bsevens@google.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@kernel.org
Link: https://patch.msgid.link/20241120124144.3814457-1-bsevens@google.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/quirks.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index cbfbb064a9c23..8bc959b60be3b 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -555,6 +555,7 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip,
static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interface *intf)
{
struct usb_host_config *config = dev->actconfig;
+ struct usb_device_descriptor new_device_descriptor;
int err;
if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD ||
@@ -566,10 +567,14 @@ static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interfac
if (err < 0)
dev_dbg(&dev->dev, "error sending boot message: %d\n", err);
err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
- &dev->descriptor, sizeof(dev->descriptor));
- config = dev->actconfig;
+ &new_device_descriptor, sizeof(new_device_descriptor));
if (err < 0)
dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err);
+ if (new_device_descriptor.bNumConfigurations > dev->descriptor.bNumConfigurations)
+ dev_dbg(&dev->dev, "error too large bNumConfigurations: %d\n",
+ new_device_descriptor.bNumConfigurations);
+ else
+ memcpy(&dev->descriptor, &new_device_descriptor, sizeof(dev->descriptor));
err = usb_reset_configuration(dev);
if (err < 0)
dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err);
@@ -901,6 +906,7 @@ static void mbox2_setup_48_24_magic(struct usb_device *dev)
static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
{
struct usb_host_config *config = dev->actconfig;
+ struct usb_device_descriptor new_device_descriptor;
int err;
u8 bootresponse[0x12];
int fwsize;
@@ -936,10 +942,14 @@ static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
dev_dbg(&dev->dev, "device initialised!\n");
err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
- &dev->descriptor, sizeof(dev->descriptor));
- config = dev->actconfig;
+ &new_device_descriptor, sizeof(new_device_descriptor));
if (err < 0)
dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err);
+ if (new_device_descriptor.bNumConfigurations > dev->descriptor.bNumConfigurations)
+ dev_dbg(&dev->dev, "error too large bNumConfigurations: %d\n",
+ new_device_descriptor.bNumConfigurations);
+ else
+ memcpy(&dev->descriptor, &new_device_descriptor, sizeof(dev->descriptor));
err = usb_reset_configuration(dev);
if (err < 0)
@@ -1249,6 +1259,7 @@ static void mbox3_setup_defaults(struct usb_device *dev)
static int snd_usb_mbox3_boot_quirk(struct usb_device *dev)
{
struct usb_host_config *config = dev->actconfig;
+ struct usb_device_descriptor new_device_descriptor;
int err;
int descriptor_size;
@@ -1262,10 +1273,14 @@ static int snd_usb_mbox3_boot_quirk(struct usb_device *dev)
dev_dbg(&dev->dev, "MBOX3: device initialised!\n");
err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
- &dev->descriptor, sizeof(dev->descriptor));
- config = dev->actconfig;
+ &new_device_descriptor, sizeof(new_device_descriptor));
if (err < 0)
dev_dbg(&dev->dev, "MBOX3: error usb_get_descriptor: %d\n", err);
+ if (new_device_descriptor.bNumConfigurations > dev->descriptor.bNumConfigurations)
+ dev_dbg(&dev->dev, "MBOX3: error too large bNumConfigurations: %d\n",
+ new_device_descriptor.bNumConfigurations);
+ else
+ memcpy(&dev->descriptor, &new_device_descriptor, sizeof(dev->descriptor));
err = usb_reset_configuration(dev);
if (err < 0)
--
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