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: v4.9.145~29
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe26b8d06e965239795bee0a71c9073bed931716;p=thirdparty%2Fkernel%2Fstable.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 851f5a553de22..67679f619c3b4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2225,7 +2225,7 @@ 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 891261b43c670..f3996ba71a594 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -696,14 +696,14 @@ 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,
@@ -712,7 +712,7 @@ 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 1db0626c8bf41..97750f162f012 100644
--- a/drivers/usb/host/hwa-hc.c
+++ b/drivers/usb/host/hwa-hc.c
@@ -654,7 +654,7 @@ 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 eba1f10e8cfda..346665a0c49dd 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -336,11 +336,11 @@ 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)))
 
 /* ----------------------------------------------------------------------- */