From b909df18ce2a998afef81d58bbd1a05dc0788c40 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Beno=C3=AEt=20Sevens?= 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 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 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 --- 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 cbfbb064a9c2..8bc959b60be3 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)