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

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 79d8bd7a612e..4ebfbd737905 100644
--- a/drivers/usb/core/usb.c
+++ b/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;
                 }