Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[sfrench/cifs-2.6.git] / drivers / hid / usbhid / hid-core.c
index 089bad8a9a21d6b35742df8819fabb4da5036730..045b5da9b992873ce74f5d401de34855b93a6f8e 100644 (file)
@@ -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);