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authorSteffen Klassert <steffen.klassert@secunet.com>2013-01-22 00:01:28 +0000
committerDavid S. Miller <davem@davemloft.net>2013-01-22 14:23:17 -0500
commitb44108dbdbaa07c609bb5755e8dd6c2035236251 (patch)
treef5c9450d05411d8d76c97ac96d9d91243c1ea5bd /net/ipv4/route.c
parent0c8729c9b914cc0360ab87171472ca7653b2aa0e (diff)
ipv4: Fix route refcount on pmtu discovery
git commit 9cb3a50c (ipv4: Invalidate the socket cached route on pmtu events if possible) introduced a refcount problem. We don't get a refcount on the route if we get it from__sk_dst_get(), but we need one if we want to reuse this route because __sk_dst_set() releases the refcount of the old route. This patch adds proper refcount handling for that case. We introduce a 'new' flag to indicate that we are going to use a new route and we release the old route only if we replace it by a new one. Reported-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r--net/ipv4/route.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 132737a7c83..a0fcc47fee7 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -985,6 +985,7 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
struct flowi4 fl4;
struct rtable *rt;
struct dst_entry *dst;
+ bool new = false;
bh_lock_sock(sk);
rt = (struct rtable *) __sk_dst_get(sk);
@@ -1000,20 +1001,26 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
if (IS_ERR(rt))
goto out;
+
+ new = true;
}
__ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
dst = dst_check(&rt->dst, 0);
if (!dst) {
+ if (new)
+ dst_release(&rt->dst);
+
rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
if (IS_ERR(rt))
goto out;
- dst = &rt->dst;
+ new = true;
}
- __sk_dst_set(sk, dst);
+ if (new)
+ __sk_dst_set(sk, &rt->dst);
out:
bh_unlock_sock(sk);