Commit 704620af authored by Mathias Payer's avatar Mathias Payer Committed by Greg Kroah-Hartman
Browse files

USB: check usb_get_extra_descriptor for proper size 



When reading an extra descriptor, we need to properly check the minimum
and maximum size allowed, to prevent from invalid data being sent by a
device.

Reported-by: default avatarHui Peng <benquike@gmail.com>
Reported-by: default avatarMathias Payer <mathias.payer@nebelwelt.net>
Co-developed-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarHui Peng <benquike@gmail.com>
Signed-off-by: default avatarMathias Payer <mathias.payer@nebelwelt.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2f2dde6b

drivers/usb/core/hub.c

+1 −1
Original line number Diff line number Diff line
@@ -2251,7 +2251,7 @@ static int usb_enumerate_device_otg(struct usb_device *udev) 
		/* descriptor may appear anywhere in config */

		err = __usb_get_extra_descriptor(udev->rawdescriptors[0],

				le16_to_cpu(udev->config[0].desc.wTotalLength),

				USB_DT_OTG, (void **) &desc);

				USB_DT_OTG, (void **) &desc, sizeof(*desc));

		if (err || !(desc->bmAttributes & USB_OTG_HNP))

			return 0;

drivers/usb/core/usb.c

+3 −3
Original line number Diff line number Diff line
@@ -832,14 +832,14 @@ EXPORT_SYMBOL_GPL(usb_get_current_frame_number); 
 */



int __usb_get_extra_descriptor(char *buffer, unsigned size,

			       unsigned char type, void **ptr)

			       unsigned char type, void **ptr, size_t minsize)

{

	struct usb_descriptor_header *header;



	while (size >= sizeof(struct usb_descriptor_header)) {

		header = (struct usb_descriptor_header *)buffer;



		if (header->bLength < 2) {

		if (header->bLength < 2 || header->bLength > size) {

			printk(KERN_ERR

				"%s: bogus descriptor, type %d length %d\n",

				usbcore_name,
@@ -848,7 +848,7 @@ int __usb_get_extra_descriptor(char *buffer, unsigned size, 
			return -1;

		}



		if (header->bDescriptorType == type) {

		if (header->bDescriptorType == type && header->bLength >= minsize) {

			*ptr = header;

			return 0;

		}

drivers/usb/host/hwa-hc.c

+1 −1
Original line number Diff line number Diff line
@@ -640,7 +640,7 @@ static int hwahc_security_create(struct hwahc *hwahc) 
	top = itr + itr_size;

	result = __usb_get_extra_descriptor(usb_dev->rawdescriptors[index],

			le16_to_cpu(usb_dev->actconfig->desc.wTotalLength),

			USB_DT_SECURITY, (void **) &secd);

			USB_DT_SECURITY, (void **) &secd, sizeof(*secd));

	if (result == -1) {

		dev_warn(dev, "BUG? WUSB host has no security descriptors\n");

		return 0;

include/linux/usb.h

+2 −2
Original line number Diff line number Diff line
@@ -407,11 +407,11 @@ struct usb_host_bos { 
};



int __usb_get_extra_descriptor(char *buffer, unsigned size,

	unsigned char type, void **ptr);

	unsigned char type, void **ptr, size_t min);

#define usb_get_extra_descriptor(ifpoint, type, ptr) \

				__usb_get_extra_descriptor((ifpoint)->extra, \

				(ifpoint)->extralen, \

				type, (void **)ptr)

				type, (void **)ptr, sizeof(**(ptr)))



/* ----------------------------------------------------------------------- */

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