unix: Fix an issue in unix_shutdown causing the other end read/write failures

Commit 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap") sets
unix domain socket peer state to TCP_CLOSE in unix_shutdown. This could
happen when the local end is shutdown but the other end is not. Then,
the other end will get read or write failures which is not expected.
Fix the issue by setting the local state to shutdown.

Fixes: 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211004232530.2377085-1-jiang.wang@bytedance.com
This commit is contained in:
Jiang Wang 2021-10-04 23:25:28 +00:00 committed by Daniel Borkmann
parent b0e875bac0
commit d0c6416bd7

View File

@ -2860,6 +2860,9 @@ static int unix_shutdown(struct socket *sock, int mode)
unix_state_lock(sk);
sk->sk_shutdown |= mode;
if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
mode == SHUTDOWN_MASK)
sk->sk_state = TCP_CLOSE;
other = unix_peer(sk);
if (other)
sock_hold(other);
@ -2882,12 +2885,10 @@ static int unix_shutdown(struct socket *sock, int mode)
other->sk_shutdown |= peer_mode;
unix_state_unlock(other);
other->sk_state_change(other);
if (peer_mode == SHUTDOWN_MASK) {
if (peer_mode == SHUTDOWN_MASK)
sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
other->sk_state = TCP_CLOSE;
} else if (peer_mode & RCV_SHUTDOWN) {
else if (peer_mode & RCV_SHUTDOWN)
sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
}
}
if (other)
sock_put(other);