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>

4 files changed, 7 insertions, 7 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 528664059a12..f76b2e0aba9d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -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;
 
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;
                 }
diff --git a/drivers/usb/host/hwa-hc.c b/drivers/usb/host/hwa-hc.c
index 684d6f074c3a..09a8ebd95588 100644
--- a/drivers/usb/host/hwa-hc.c
+++ b/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;
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 4cdd515a4385..5e49e82c4368 100644
--- a/include/linux/usb.h
+++ b/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)))
 
 /* ----------------------------------------------------------------------- */