Commits
Florian Westphal committed d93c6258ee4
netfilter: conntrack: resched in nf_ct_iterate_cleanup Ulrich reports soft lockup with following (shortened) callchain: NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! __netif_receive_skb_core+0x6e4/0x774 process_backlog+0x94/0x160 net_rx_action+0x88/0x178 call_do_softirq+0x24/0x3c do_softirq+0x54/0x6c __local_bh_enable_ip+0x7c/0xbc nf_ct_iterate_cleanup+0x11c/0x22c [nf_conntrack] masq_inet_event+0x20/0x30 [nf_nat_masquerade_ipv6] atomic_notifier_call_chain+0x1c/0x2c ipv6_del_addr+0x1bc/0x220 [ipv6] Problem is that nf_ct_iterate_cleanup can run for a very long time since it can be interrupted by softirq processing. Moreover, atomic_notifier_call_chain runs with rcu readlock held. So lets call cond_resched() in nf_ct_iterate_cleanup and defer the call to a work queue for the atomic_notifier_call_chain case. We also need another cond_resched in get_next_corpse, since we have to deal with iter() always returning false, in that case get_next_corpse will walk entire conntrack table. Reported-by: Ulrich Weber <uw@ocedo.com> Tested-by: Ulrich Weber <uw@ocedo.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>