From 68b80f11380889996aa7eadba29dbbb5c29a5864 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Tue, 17 Jun 2008 15:51:47 -0700 Subject: netfilter: nf_nat: fix RCU races Fix three ct_extend/NAT extension related races: - When cleaning up the extension area and removing it from the bysource hash, the nat->ct pointer must not be set to NULL since it may still be used in a RCU read side - When replacing a NAT extension area in the bysource hash, the nat->ct pointer must be assigned before performing the replacement - When reallocating extension storage in ct_extend, the old memory must not be freed immediately since it may still be used by a RCU read side Possibly fixes https://bugzilla.redhat.com/show_bug.cgi?id=449315 and/or http://bugzilla.kernel.org/show_bug.cgi?id=10875 Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/nf_nat_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c index 04578593e10..d2a887fc8d9 100644 --- a/net/ipv4/netfilter/nf_nat_core.c +++ b/net/ipv4/netfilter/nf_nat_core.c @@ -556,7 +556,6 @@ static void nf_nat_cleanup_conntrack(struct nf_conn *ct) spin_lock_bh(&nf_nat_lock); hlist_del_rcu(&nat->bysource); - nat->ct = NULL; spin_unlock_bh(&nf_nat_lock); } @@ -570,8 +569,8 @@ static void nf_nat_move_storage(void *new, void *old) return; spin_lock_bh(&nf_nat_lock); - hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource); new_nat->ct = ct; + hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource); spin_unlock_bh(&nf_nat_lock); } -- cgit v1.2.3