Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

Pull HID fixes from Jiri Kosina:

 - fix for potential out-of-bounds memory access (found by fuzzing,
   likely requires specially crafted device to trigger) by Jaejoong Kim

 - two new device IDs for elecom driver from Alex Manoussakis

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: hid-elecom: extend to fix descriptor for HUGE trackball
  HID: usbhid: fix out-of-bounds bug

drivers/hid/Kconfig

@@ -281,6 +281,7 @@ config HID_ELECOM
 	Support for ELECOM devices:
 	  - BM084 Bluetooth Mouse
 	  - DEFT Trackball (Wired and wireless)
+	  - HUGE Trackball (Wired and wireless)
 
 config HID_ELO
 	tristate "ELO USB 4000/4500 touchscreen"

drivers/hid/hid-core.c

@@ -2032,6 +2032,8 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRED) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRELESS) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_HUGE_WIRED) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_HUGE_WIRELESS) },
 #endif
 #if IS_ENABLED(CONFIG_HID_ELO)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009) },

drivers/hid/hid-elecom.c

@@ -3,6 +3,7 @@
  *  Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com>
  *  Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com>
  *  Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu>
+ *  Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org>
  */
 
 /*
@@ -32,9 +33,11 @@ static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		break;
 	case USB_DEVICE_ID_ELECOM_DEFT_WIRED:
 	case USB_DEVICE_ID_ELECOM_DEFT_WIRELESS:
-		/* The DEFT trackball has eight buttons, but its descriptor only
-		 * reports five, disabling the three Fn buttons on the top of
-		 * the mouse.
+	case USB_DEVICE_ID_ELECOM_HUGE_WIRED:
+	case USB_DEVICE_ID_ELECOM_HUGE_WIRELESS:
+		/* The DEFT/HUGE trackball has eight buttons, but its descriptor
+		 * only reports five, disabling the three Fn buttons on the top
+		 * of the mouse.
 		 *
 		 * Apply the following diff to the descriptor:
 		 *
@@ -62,7 +65,7 @@ static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		 * End Collection,                     End Collection,
 		 */
 		if (*rsize == 213 && rdesc[13] == 5 && rdesc[21] == 5) {
-			hid_info(hdev, "Fixing up Elecom DEFT Fn buttons\n");
+			hid_info(hdev, "Fixing up Elecom DEFT/HUGE Fn buttons\n");
 			rdesc[13] = 8; /* Button/Variable Report Count */
 			rdesc[21] = 8; /* Button/Variable Usage Maximum */
 			rdesc[29] = 0; /* Button/Constant Report Count */
@@ -76,6 +79,8 @@ static const struct hid_device_id elecom_devices[] = {
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRED) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRELESS) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_HUGE_WIRED) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_HUGE_WIRELESS) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, elecom_devices);

drivers/hid/hid-ids.h

@@ -368,6 +368,8 @@
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061
 #define USB_DEVICE_ID_ELECOM_DEFT_WIRED	0x00fe
 #define USB_DEVICE_ID_ELECOM_DEFT_WIRELESS	0x00ff
+#define USB_DEVICE_ID_ELECOM_HUGE_WIRED	0x010c
+#define USB_DEVICE_ID_ELECOM_HUGE_WIRELESS	0x010d
 
 #define USB_VENDOR_ID_DREAM_CHEEKY	0x1d34
 #define USB_DEVICE_ID_DREAM_CHEEKY_WN	0x0004

drivers/hid/usbhid/hid-core.c

@@ -975,6 +975,8 @@ static int usbhid_parse(struct hid_device *hid)
 	unsigned int rsize = 0;
 	char *rdesc;
 	int ret, n;
+	int num_descriptors;
+	size_t offset = offsetof(struct hid_descriptor, desc);
 
 	quirks = usbhid_lookup_quirk(le16_to_cpu(dev->descriptor.idVendor),
 			le16_to_cpu(dev->descriptor.idProduct));
@@ -997,10 +999,18 @@ static int usbhid_parse(struct hid_device *hid)
 		return -ENODEV;
 	}
 
+	if (hdesc->bLength < sizeof(struct hid_descriptor)) {
+		dbg_hid("hid descriptor is too short\n");
+		return -EINVAL;
+	}
+
 	hid->version = le16_to_cpu(hdesc->bcdHID);
 	hid->country = hdesc->bCountryCode;
 
-	for (n = 0; n < hdesc->bNumDescriptors; n++)
+	num_descriptors = min_t(int, hdesc->bNumDescriptors,
+	       (hdesc->bLength - offset) / sizeof(struct hid_class_descriptor));
+
+	for (n = 0; n < num_descriptors; n++)
 		if (hdesc->desc[n].bDescriptorType == HID_DT_REPORT)
 			rsize = le16_to_cpu(hdesc->desc[n].wDescriptorLength);