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;