af_netlink: Add needed scm_destroy after scm_send.

scm_send occasionally allocates state in the scm_cookie, so I have
modified netlink_sendmsg to guarantee that when scm_send succeeds
scm_destory will be called to free that state.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 3 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a2eb965207d3..7aeaa83193db 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1323,19 +1323,23 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
         if (msg->msg_flags&MSG_OOB)
                 return -EOPNOTSUPP;
 
-        if (NULL == siocb->scm)
+        if (NULL == siocb->scm) {
                 siocb->scm = &scm;
+                memset(&scm, 0, sizeof(scm));
+        }
         err = scm_send(sock, msg, siocb->scm);
         if (err < 0)
                 return err;
 
         if (msg->msg_namelen) {
+                err = -EINVAL;
                 if (addr->nl_family != AF_NETLINK)
-                        return -EINVAL;
+                        goto out;
                 dst_pid = addr->nl_pid;
                 dst_group = ffs(addr->nl_groups);
+                err =  -EPERM;
                 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
-                        return -EPERM;
+                        goto out;
         } else {
                 dst_pid = nlk->dst_pid;
                 dst_group = nlk->dst_group;
@@ -1387,6 +1391,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
         err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
 
 out:
+        scm_destroy(siocb->scm);
         return err;
 }