1 files changed, 31 insertions, 22 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e1f1349fae8..5fe9d6fe08b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1316,18 +1316,20 @@ 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 */
@@ -1350,10 +1352,22 @@ 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.
  */
@@ -1410,12 +1424,9 @@ 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);
@@ -1585,16 +1596,14 @@ 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) {
@@ -1711,7 +1720,7 @@ 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)) {
@@ -1860,14 +1869,14 @@ 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;
                 }