rtnetlink: release net refcnt on error in do_setlink()

[ Upstream commit e0ebde0e131b529fd721b24f62872def5ec3718c ]

rtnl_link_get_net() holds a reference on the 'struct net', we need to release
it in case of error.

CC: Eric W. Biederman <ebiederm@xmission.com>
Fixes: b51642f6d77b ("net: Enable a userns root rtnl calls that are safe for unprivilged users")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index b0db904f083d2a348db0c2df838df21ca7bebd5c..46175866851ef6f5736598287459c8ac4c1736b6 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1453,6 +1453,7 @@ static int do_setlink(const struct sk_buff *skb,
                        goto errout;
                }
                if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) {
+                       put_net(net);
                        err = -EPERM;
                        goto errout;
                }