[IPV6]: Fix refcounting for anycast dst entries.

Anycast DST entries allocated inside ipv6_dev_ac_inc are leaked when
network device is stopped without removing IPv6 addresses from it. The
bug has been observed in the reality on 2.6.18-rhel5 kernel.

In the above case addrconf_ifdown marks all entries as obsolete and
ip6_del_rt called from __ipv6_dev_ac_dec returns ENOENT. The
referrence is not dropped.

The fix is simple. DST entry should not keep referrence when stored in
the FIB6 tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 9c7f83fbc3a1d28b89bf7f26115c4d8d39f92085..e5f56c953b58f8ab989c51d90eab205567de6b14 100644 (file)
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -334,9 +334,7 @@ int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
        idev->ac_list = aca;
        write_unlock_bh(&idev->lock);
 
-       dst_hold(&rt->u.dst);
-       if (ip6_ins_rt(rt))
-               dst_release(&rt->u.dst);
+       ip6_ins_rt(rt);
 
        addrconf_join_solict(dev, &aca->aca_addr);
 
@@ -378,10 +376,7 @@ int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
        addrconf_leave_solict(idev, &aca->aca_addr);
 
        dst_hold(&aca->aca_rt->u.dst);
-       if (ip6_del_rt(aca->aca_rt))
-               dst_free(&aca->aca_rt->u.dst);
-       else
-               dst_release(&aca->aca_rt->u.dst);
+       ip6_del_rt(aca->aca_rt);
 
        aca_put(aca);
        return 0;