diff options
| -rw-r--r-- | net/unix/af_unix.c | 43 |
1 files changed, 38 insertions, 5 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 453ede86a65b..87c794d8fa2d 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -858,6 +858,31 @@ out_mknod_parent: goto out_up; } +static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) +{ + if (unlikely(sk1 == sk2) || !sk2) { + unix_state_lock(sk1); + return; + } + if (sk1 < sk2) { + unix_state_lock(sk1); + unix_state_lock_nested(sk2); + } else { + unix_state_lock(sk2); + unix_state_lock_nested(sk1); + } +} + +static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) +{ + if (unlikely(sk1 == sk2) || !sk2) { + unix_state_unlock(sk1); + return; + } + unix_state_unlock(sk1); + unix_state_unlock(sk2); +} + static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags) { @@ -877,11 +902,19 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) goto out; +restart: other=unix_find_other(sunaddr, alen, sock->type, hash, &err); if (!other) goto out; - unix_state_lock(sk); + unix_state_double_lock(sk, other); + + /* Apparently VFS overslept socket death. Retry. */ + if (sock_flag(other, SOCK_DEAD)) { + unix_state_double_unlock(sk, other); + sock_put(other); + goto restart; + } err = -EPERM; if (!unix_may_send(sk, other)) @@ -896,7 +929,7 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, * 1003.1g breaking connected state with AF_UNSPEC */ other = NULL; - unix_state_lock(sk); + unix_state_double_lock(sk, other); } /* @@ -905,19 +938,19 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, if (unix_peer(sk)) { struct sock *old_peer = unix_peer(sk); unix_peer(sk)=other; - unix_state_unlock(sk); + unix_state_double_unlock(sk, other); if (other != old_peer) unix_dgram_disconnected(sk, old_peer); sock_put(old_peer); } else { unix_peer(sk)=other; - unix_state_unlock(sk); + unix_state_double_unlock(sk, other); } return 0; out_unlock: - unix_state_unlock(sk); + unix_state_double_unlock(sk, other); sock_put(other); out: return err; |