From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
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@xxxxxxxxx>
Reported-by: Kerin Millar <kerframil@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
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 1068769..b49da6c 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;
--
1.7.2.5
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