1 files changed, 36 insertions, 17 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 015606b54d9b..eb90f77bb0e2 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1,7 +1,7 @@
 /*
  * NET4:        Implementation of BSD Unix domain sockets.
  *
- * Authors:     Alan Cox, <alan.cox@linux.org>
+ * Authors:     Alan Cox, <alan@lxorguk.ukuu.org.uk>
  *
  *              This program is free software; you can redistribute it and/or
  *              modify it under the terms of the GNU General Public License
@@ -711,28 +711,30 @@ static struct sock *unix_find_other(struct net *net,
                                     int type, unsigned hash, int *error)
 {
         struct sock *u;
-        struct nameidata nd;
+        struct path path;
         int err = 0;
 
         if (sunname->sun_path[0]) {
-                err = path_lookup(sunname->sun_path, LOOKUP_FOLLOW, &nd);
+                struct inode *inode;
+                err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
                 if (err)
                         goto fail;
-                err = vfs_permission(&nd, MAY_WRITE);
+                inode = path.dentry->d_inode;
+                err = inode_permission(inode, MAY_WRITE);
                 if (err)
                         goto put_fail;
 
                 err = -ECONNREFUSED;
-                if (!S_ISSOCK(nd.path.dentry->d_inode->i_mode))
+                if (!S_ISSOCK(inode->i_mode))
                         goto put_fail;
-                u = unix_find_socket_byinode(net, nd.path.dentry->d_inode);
+                u = unix_find_socket_byinode(net, inode);
                 if (!u)
                         goto put_fail;
 
                 if (u->sk_type == type)
-                        touch_atime(nd.path.mnt, nd.path.dentry);
+                        touch_atime(path.mnt, path.dentry);
 
-                path_put(&nd.path);
+                path_put(&path);
 
                 err=-EPROTOTYPE;
                 if (u->sk_type != type) {
@@ -753,7 +755,7 @@ static struct sock *unix_find_other(struct net *net,
         return u;
 
 put_fail:
-        path_put(&nd.path);
+        path_put(&path);
 fail:
         *error=err;
         return NULL;
@@ -1300,14 +1302,23 @@ static void unix_destruct_fds(struct sk_buff *skb)
         sock_wfree(skb);
 }
 
-static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
 {
         int i;
+
+        /*
+         * Need to duplicate file references for the sake of garbage
+         * collection.  Otherwise a socket in the fps might become a
+         * candidate for GC while the skb is not yet queued.
+         */
+        UNIXCB(skb).fp = scm_fp_dup(scm->fp);
+        if (!UNIXCB(skb).fp)
+                return -ENOMEM;
+
         for (i=scm->fp->count-1; i>=0; i--)
                 unix_inflight(scm->fp->fp[i]);
-        UNIXCB(skb).fp = scm->fp;
         skb->destructor = unix_destruct_fds;
-        scm->fp = NULL;
+        return 0;
 }
 
 /*
@@ -1366,8 +1377,11 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
                 goto out;
 
         memcpy(UNIXCREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
-        if (siocb->scm->fp)
-                unix_attach_fds(siocb->scm, skb);
+        if (siocb->scm->fp) {
+                err = unix_attach_fds(siocb->scm, skb);
+                if (err)
+                        goto out_free;
+        }
         unix_get_secdata(siocb->scm, skb);
 
         skb_reset_transport_header(skb);
@@ -1536,8 +1550,13 @@ 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));
-                if (siocb->scm->fp)
-                        unix_attach_fds(siocb->scm, skb);
+                if (siocb->scm->fp) {
+                        err = unix_attach_fds(siocb->scm, skb);
+                        if (err) {
+                                kfree_skb(skb);
+                                goto out_err;
+                        }
+                }
 
                 if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
                         kfree_skb(skb);
@@ -2211,7 +2230,7 @@ static int unix_net_init(struct net *net)
 #endif
         error = 0;
 out:
-        return 0;
+        return error;
 }
 
 static void unix_net_exit(struct net *net)