phonet/pep: refuse to enable an unbound pipe

stable inclusion
from stable-v5.10.89
commit 52ad5da8e316fa11e3a50b3f089aa63e4089bf52
bugzilla: 186140 https://gitee.com/openeuler/kernel/issues/I4S8HA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=52ad5da8e316fa11e3a50b3f089aa63e4089bf52



--------------------------------

commit 75a2f315 upstream.

This ioctl() implicitly assumed that the socket was already bound to
a valid local socket name, i.e. Phonet object. If the socket was not
bound, two separate problems would occur:

1) We'd send an pipe enablement request with an invalid source object.
2) Later socket calls could BUG on the socket unexpectedly being
   connected yet not bound to a valid object.

Reported-by:  <syzbot+2dc91e7fc3dea88b1e8a@syzkaller.appspotmail.com>
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>