diff options
Diffstat (limited to 'net/unix')
| -rw-r--r-- | net/unix/af_unix.c | 34 |
1 files changed, 9 insertions, 25 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 11cb5badaf..be5266007b 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1473,6 +1473,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, struct unix_sock *u = unix_sk(sk), *newu, *otheru; struct net *net = sock_net(sk); struct sk_buff *skb = NULL; + unsigned char state; long timeo; int err; @@ -1523,7 +1524,6 @@ restart: goto out; } - /* Latch state of peer */ unix_state_lock(other); /* Apparently VFS overslept socket death. Retry. */ @@ -1553,37 +1553,21 @@ restart: goto restart; } - /* Latch our state. - - It is tricky place. We need to grab our state lock and cannot - drop lock on peer. It is dangerous because deadlock is - possible. Connect to self case and simultaneous - attempt to connect are eliminated by checking socket - state. other is TCP_LISTEN, if sk is TCP_LISTEN we - check this before attempt to grab lock. - - Well, and we have to recheck the state after socket locked. + /* self connect and simultaneous connect are eliminated + * by rejecting TCP_LISTEN socket to avoid deadlock. */ - switch (READ_ONCE(sk->sk_state)) { - case TCP_CLOSE: - /* This is ok... continue with connect */ - break; - case TCP_ESTABLISHED: - /* Socket is already connected */ - err = -EISCONN; - goto out_unlock; - default: - err = -EINVAL; + state = READ_ONCE(sk->sk_state); + if (unlikely(state != TCP_CLOSE)) { + err = state == TCP_ESTABLISHED ? -EISCONN : -EINVAL; goto out_unlock; } unix_state_lock_nested(sk, U_LOCK_SECOND); - if (sk->sk_state != TCP_CLOSE) { + if (unlikely(sk->sk_state != TCP_CLOSE)) { + err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EINVAL; unix_state_unlock(sk); - unix_state_unlock(other); - sock_put(other); - goto restart; + goto out_unlock; } err = security_unix_stream_connect(sk, other, newsk); |