Bluetooth: hidp: fix buffer overflow

commit a1616a5a upstream.

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
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/bluetooth/hidp/sock.c

@@ -76,6 +76,7 @@ static int hidp_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long
 			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)))