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Diffstat (limited to 'net')
-rw-r--r--net/unix/af_unix.c43
1 files changed, 38 insertions, 5 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 453ede86a65..87c794d8fa2 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;