can: isotp: isotp_getname(): fix kernel information leak

commit b42b3a27

 upstream.

Initialize the sockaddr_can structure to prevent a data leak to user space.

Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Reported-by:  <syzbot+057884e2f453e8afebc8@syzkaller.appspotmail.com>
Fixes: e057dd3f

 ("can: add ISO 15765-2:2016 transport protocol")
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20210112091643.11789-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>