[Devel] [PATCH 3/3] [IPV6]: Fix refcounting for anycast dst entries.

[Denis V. Lunev]

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 at openvz.org>
---
 net/ipv6/anycast.c |    9 ++-------
 1 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 96868b9..7bc0469 100644
--- 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;
-- 
1.5.3.rc5

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