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 (cherry picked from commit b909df18ce2a998afef81d58bbd1a05dc0788c40) Signed-off-by: Benoît Sevens bsevens@google.com --- sound/usb/quirks.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index 752422147fb3..18c879ddc076 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -595,6 +595,7 @@ 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 || @@ -606,10 +607,14 @@ 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); @@ -941,6 +946,7 @@ 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; @@ -976,10 +982,14 @@ 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)