USB: check usb_get_extra_descriptor for proper size

commit 704620afc70cf47abb9d6a1a57f3825d2bca49cf upstream.

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: NHui Peng <benquike@gmail.com>
Reported-by: NMathias Payer <mathias.payer@nebelwelt.net>
Co-developed-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NHui Peng <benquike@gmail.com>
Signed-off-by: NMathias Payer <mathias.payer@nebelwelt.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hub.c

@@ -2250,7 +2250,7 @@ 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

@@ -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

@@ -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

@@ -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)))
 
 /* ----------------------------------------------------------------------- */