From: Mathias Payer <mathias.payer@nebelwelt.net>
Date: Wed, 5 Dec 2018 20:19:59 +0000 (+0100)
Subject: USB: check usb_get_extra_descriptor for proper size
X-Git-Tag: v4.19.9~61
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1b2e742bf7230ce04cda5b7348f922174bef2d7a;p=platform%2Fkernel%2Flinux-rpi3.git

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: 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>
---

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f79979a..cc62707 100644
--- a/drivers/usb/core/hub.c
+++ b/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;
 
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 79d8bd7..4ebfbd7 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 684d6f0..09a8ebd 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 4cdd515..5e49e82 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)))
 
 /* ----------------------------------------------------------------------- */