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| author | Florian Westphal <fw@strlen.de> | 2016-01-20 11:16:43 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-02-01 00:15:26 +0100 |
| commit | d93c6258ee4255749c10012c50a31c08f4e9fb16 (patch) | |
| tree | bb2ca281b4a2467572b3541780a0b74088e75de3 /net/netfilter | |
| parent | 53729eb174c1589f9185340ffe8c10b3f39f3ef3 (diff) | |
| download | linux-d93c6258ee4255749c10012c50a31c08f4e9fb16.tar.gz | |
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>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/nf_conntrack_core.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 58882de06bd7..f60b4fdeeb8c 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1412,6 +1412,7 @@ get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data), } spin_unlock(lockp); local_bh_enable(); + cond_resched(); } for_each_possible_cpu(cpu) { @@ -1424,6 +1425,7 @@ get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data), set_bit(IPS_DYING_BIT, &ct->status); } spin_unlock_bh(&pcpu->lock); + cond_resched(); } return NULL; found: @@ -1440,6 +1442,8 @@ void nf_ct_iterate_cleanup(struct net *net, struct nf_conn *ct; unsigned int bucket = 0; + might_sleep(); + while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) { /* Time to push up daises... */ if (del_timer(&ct->timeout)) @@ -1448,6 +1452,7 @@ void nf_ct_iterate_cleanup(struct net *net, /* ... else the timer will get him soon. */ nf_ct_put(ct); + cond_resched(); } } EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); |