HID: fix HIDIOCGRDESC memory access in hidraw
Fix bogus copying of data into userspace when HIDIOCGRDESC is issued.
HID-transport layer makes sure that dev->hid->rdesc is not larger than
HID_MAX_DESCRIPTOR_SIZE.
Noticed-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 8503197..a702e2f 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -229,9 +229,15 @@
if (get_user(len, (int __user *)arg))
return -EFAULT;
- if (copy_to_user(*((__u8 **)(user_arg +
- sizeof(__u32))),
- dev->hid->rdesc, len))
+
+ if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
+ return -EINVAL;
+
+ if (copy_to_user(user_arg + offsetof(
+ struct hidraw_report_descriptor,
+ value[0]),
+ dev->hid->rdesc,
+ min(dev->hid->rsize, len)))
return -EFAULT;
return 0;
}