Bluetooth: hidp: fix buffer overflow

Struct ca is copied from userspace. It is not checked whether the "name"
field is NULL terminated, which allows local users to obtain potentially
sensitive information from kernel stack memory, via a HIDPCONNADD command.

This vulnerability is similar to CVE-2011-1079.
Signed-off-by: NYoung Xiao <YangX92@hotmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

net/bluetooth/hidp/sock.c

@@ -75,6 +75,7 @@ static int do_hidp_sock_ioctl(struct socket *sock, unsigned int cmd, void __user
 			sockfd_put(csock);
 			return err;
 		}
+		ca.name[sizeof(ca.name)-1] = 0;
 
 		err = hidp_connection_add(&ca, csock, isock);
 		if (!err && copy_to_user(argp, &ca, sizeof(ca)))