diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-03-16 02:00:34 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-03-17 01:47:08 -0700 |
| commit | a16a1647fa6b6783c2e91623e72e86f0c2adac5e (patch) | |
| tree | 949b73345b860aec586d67243eab4a9944a158ad | |
| parent | c577923756b7fe9071f28a76b66b83b306d1d001 (diff) | |
netfilter: ctnetlink: fix race between delete and timeout expiration
Kerin Millar reported hardlockups while running `conntrackd -c'
in a busy firewall. That system (with several processors) was
acting as backup in a primary-backup setup.
After several tries, I found a race condition between the deletion
operation of ctnetlink and timeout expiration. This patch fixes
this problem.
Tested-by: Kerin Millar <kerframil@gmail.com>
Reported-by: Kerin Millar <kerframil@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 10687692831e..b49da6c925b3 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -943,20 +943,21 @@ ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb, } } - if (nf_conntrack_event_report(IPCT_DESTROY, ct, - NETLINK_CB(skb).pid, - nlmsg_report(nlh)) < 0) { + if (del_timer(&ct->timeout)) { + if (nf_conntrack_event_report(IPCT_DESTROY, ct, + NETLINK_CB(skb).pid, + nlmsg_report(nlh)) < 0) { + nf_ct_delete_from_lists(ct); + /* we failed to report the event, try later */ + nf_ct_insert_dying_list(ct); + nf_ct_put(ct); + return 0; + } + /* death_by_timeout would report the event again */ + set_bit(IPS_DYING_BIT, &ct->status); nf_ct_delete_from_lists(ct); - /* we failed to report the event, try later */ - nf_ct_insert_dying_list(ct); nf_ct_put(ct); - return 0; } - - /* death_by_timeout would report the event again */ - set_bit(IPS_DYING_BIT, &ct->status); - - nf_ct_kill(ct); nf_ct_put(ct); return 0; |