1 files changed, 74 insertions, 40 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index fef2cc5e9d2b..0b39b2451ea5 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -282,7 +282,7 @@ static inline struct sock *unix_find_socket_byname(struct net *net,
         return s;
 }
 
-static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
+static struct sock *unix_find_socket_byinode(struct inode *i)
 {
         struct sock *s;
         struct hlist_node *node;
@@ -292,9 +292,6 @@ static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
                     &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
                 struct dentry *dentry = unix_sk(s)->dentry;
 
-                if (!net_eq(sock_net(s), net))
-                        continue;
-
                 if (dentry && dentry->d_inode == i) {
                         sock_hold(s);
                         goto found;
@@ -450,11 +447,31 @@ static int unix_release_sock(struct sock *sk, int embrion)
         return 0;
 }
 
+static void init_peercred(struct sock *sk)
+{
+        put_pid(sk->sk_peer_pid);
+        if (sk->sk_peer_cred)
+                put_cred(sk->sk_peer_cred);
+        sk->sk_peer_pid  = get_pid(task_tgid(current));
+        sk->sk_peer_cred = get_current_cred();
+}
+
+static void copy_peercred(struct sock *sk, struct sock *peersk)
+{
+        put_pid(sk->sk_peer_pid);
+        if (sk->sk_peer_cred)
+                put_cred(sk->sk_peer_cred);
+        sk->sk_peer_pid  = get_pid(peersk->sk_peer_pid);
+        sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
+}
+
 static int unix_listen(struct socket *sock, int backlog)
 {
         int err;
         struct sock *sk = sock->sk;
         struct unix_sock *u = unix_sk(sk);
+        struct pid *old_pid = NULL;
+        const struct cred *old_cred = NULL;
 
         err = -EOPNOTSUPP;
         if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
@@ -470,12 +487,14 @@ static int unix_listen(struct socket *sock, int backlog)
         sk->sk_max_ack_backlog  = backlog;
         sk->sk_state            = TCP_LISTEN;
         /* set credentials so connect can copy them */
-        sk->sk_peercred.pid     = task_tgid_vnr(current);
-        current_euid_egid(&sk->sk_peercred.uid, &sk->sk_peercred.gid);
+        init_peercred(sk);
         err = 0;
 
 out_unlock:
         unix_state_unlock(sk);
+        put_pid(old_pid);
+        if (old_cred)
+                put_cred(old_cred);
 out:
         return err;
 }
@@ -673,6 +692,7 @@ static int unix_autobind(struct socket *sock)
         static u32 ordernum = 1;
         struct unix_address *addr;
         int err;
+        unsigned int retries = 0;
 
         mutex_lock(&u->readlock);
 
@@ -698,9 +718,17 @@ retry:
         if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
                                       addr->hash)) {
                 spin_unlock(&unix_table_lock);
-                /* Sanity yield. It is unusual case, but yet... */
-                if (!(ordernum&0xFF))
-                        yield();
+                /*
+                 * __unix_find_socket_byname() may take long time if many names
+                 * are already in use.
+                 */
+                cond_resched();
+                /* Give up if all names seems to be in use. */
+                if (retries++ == 0xFFFFF) {
+                        err = -ENOSPC;
+                        kfree(addr);
+                        goto out;
+                }
                 goto retry;
         }
         addr->hash ^= sk->sk_type;
@@ -736,7 +764,7 @@ static struct sock *unix_find_other(struct net *net,
                 err = -ECONNREFUSED;
                 if (!S_ISSOCK(inode->i_mode))
                         goto put_fail;
-                u = unix_find_socket_byinode(net, inode);
+                u = unix_find_socket_byinode(inode);
                 if (!u)
                         goto put_fail;
 
@@ -1140,8 +1168,7 @@ restart:
         unix_peer(newsk)        = sk;
         newsk->sk_state         = TCP_ESTABLISHED;
         newsk->sk_type          = sk->sk_type;
-        newsk->sk_peercred.pid  = task_tgid_vnr(current);
-        current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid);
+        init_peercred(newsk);
         newu = unix_sk(newsk);
         newsk->sk_wq            = &newu->peer_wq;
         otheru = unix_sk(other);
@@ -1157,7 +1184,7 @@ restart:
         }
 
         /* Set credentials */
-        sk->sk_peercred = other->sk_peercred;
+        copy_peercred(sk, other);
 
         sock->state     = SS_CONNECTED;
         sk->sk_state    = TCP_ESTABLISHED;
@@ -1199,10 +1226,8 @@ static int unix_socketpair(struct socket *socka, struct socket *sockb)
         sock_hold(skb);
         unix_peer(ska) = skb;
         unix_peer(skb) = ska;
-        ska->sk_peercred.pid = skb->sk_peercred.pid = task_tgid_vnr(current);
-        current_euid_egid(&skb->sk_peercred.uid, &skb->sk_peercred.gid);
-        ska->sk_peercred.uid = skb->sk_peercred.uid;
-        ska->sk_peercred.gid = skb->sk_peercred.gid;
+        init_peercred(ska);
+        init_peercred(skb);
 
         if (ska->sk_type != SOCK_DGRAM) {
                 ska->sk_state = TCP_ESTABLISHED;
@@ -1297,18 +1322,20 @@ static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
         int i;
 
         scm->fp = UNIXCB(skb).fp;
-        skb->destructor = sock_wfree;
         UNIXCB(skb).fp = NULL;
 
         for (i = scm->fp->count-1; i >= 0; i--)
                 unix_notinflight(scm->fp->fp[i]);
 }
 
-static void unix_destruct_fds(struct sk_buff *skb)
+static void unix_destruct_scm(struct sk_buff *skb)
 {
         struct scm_cookie scm;
         memset(&scm, 0, sizeof(scm));
-        unix_detach_fds(&scm, skb);
+        scm.pid  = UNIXCB(skb).pid;
+        scm.cred = UNIXCB(skb).cred;
+        if (UNIXCB(skb).fp)
+                unix_detach_fds(&scm, skb);
 
         /* Alas, it calls VFS */
         /* So fscking what? fput() had been SMP-safe since the last Summer */
@@ -1331,10 +1358,22 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
 
         for (i = scm->fp->count-1; i >= 0; i--)
                 unix_inflight(scm->fp->fp[i]);
-        skb->destructor = unix_destruct_fds;
         return 0;
 }
 
+static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
+{
+        int err = 0;
+        UNIXCB(skb).pid  = get_pid(scm->pid);
+        UNIXCB(skb).cred = get_cred(scm->cred);
+        UNIXCB(skb).fp = NULL;
+        if (scm->fp && send_fds)
+                err = unix_attach_fds(scm, skb);
+
+        skb->destructor = unix_destruct_scm;
+        return err;
+}
+
 /*
  *      Send AF_UNIX data.
  */
@@ -1391,12 +1430,9 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
         if (skb == NULL)
                 goto out;
 
-        memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
-        if (siocb->scm->fp) {
-                err = unix_attach_fds(siocb->scm, skb);
-                if (err)
-                        goto out_free;
-        }
+        err = unix_scm_to_skb(siocb->scm, skb, true);
+        if (err)
+                goto out_free;
         unix_get_secdata(siocb->scm, skb);
 
         skb_reset_transport_header(skb);
@@ -1566,16 +1602,14 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
                  */
                 size = min_t(int, size, skb_tailroom(skb));
 
-                memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
+
                 /* Only send the fds in the first buffer */
-                if (siocb->scm->fp && !fds_sent) {
-                        err = unix_attach_fds(siocb->scm, skb);
-                        if (err) {
-                                kfree_skb(skb);
-                                goto out_err;
-                        }
-                        fds_sent = true;
+                err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);
+                if (err) {
+                        kfree_skb(skb);
+                        goto out_err;
                 }
+                fds_sent = true;
 
                 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
                 if (err) {
@@ -1692,7 +1726,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
                 siocb->scm = &tmp_scm;
                 memset(&tmp_scm, 0, sizeof(tmp_scm));
         }
-        siocb->scm->creds = *UNIXCREDS(skb);
+        scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
         unix_set_secdata(siocb->scm, skb);
 
         if (!(flags & MSG_PEEK)) {
@@ -1841,14 +1875,14 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 
                 if (check_creds) {
                         /* Never glue messages from different writers */
-                        if (memcmp(UNIXCREDS(skb), &siocb->scm->creds,
-                                   sizeof(siocb->scm->creds)) != 0) {
+                        if ((UNIXCB(skb).pid  != siocb->scm->pid) ||
+                            (UNIXCB(skb).cred != siocb->scm->cred)) {
                                 skb_queue_head(&sk->sk_receive_queue, skb);
                                 break;
                         }
                 } else {
                         /* Copy credentials */
-                        siocb->scm->creds = *UNIXCREDS(skb);
+                        scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
                         check_creds = 1;
                 }
 
@@ -1881,7 +1915,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
                                 break;
                         }
 
-                        kfree_skb(skb);
+                        consume_skb(skb);
 
                         if (siocb->scm->fp)
                                 break;