From 3bfe049807c240344b407e3cfb74544927359817 Mon Sep 17 00:00:00 2001 From: Francesco Ruggeri Date: Sun, 17 May 2015 14:30:31 -0700 Subject: netfilter: nfnetlink_{log,queue}: Register pernet in first place nfnetlink_{log,queue}_init() register the netlink callback nf*_rcv_nl_event before registering the pernet_subsys, but the callback relies on data structures allocated by pernet init functions. When nfnetlink_{log,queue} is loaded, if a netlink message is received after the netlink callback is registered but before the pernet_subsys is registered, the kernel will panic in the sequence nfulnl_rcv_nl_event nfnl_log_pernet net_generic BUG_ON(id == 0) where id is nfnl_log_net_id. The panic can be easily reproduced in 4.0.3 by: while true ;do modprobe nfnetlink_log ; rmmod nfnetlink_log ; done & while true ;do ip netns add dummy ; ip netns del dummy ; done & This patch moves register_pernet_subsys to earlier in nfnetlink_log_init. Notice that the BUG_ON hit in 4.0.3 was recently removed in 2591ffd308 ["netns: remove BUG_ONs from net_generic()"]. Signed-off-by: Francesco Ruggeri Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_log.c | 19 ++++++++++--------- net/netfilter/nfnetlink_queue_core.c | 18 +++++++++--------- 2 files changed, 19 insertions(+), 18 deletions(-) (limited to 'net') diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 3ad91266c821..4ef1fae8445e 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -1073,7 +1073,13 @@ static struct pernet_operations nfnl_log_net_ops = { static int __init nfnetlink_log_init(void) { - int status = -ENOMEM; + int status; + + status = register_pernet_subsys(&nfnl_log_net_ops); + if (status < 0) { + pr_err("failed to register pernet ops\n"); + goto out; + } netlink_register_notifier(&nfulnl_rtnl_notifier); status = nfnetlink_subsys_register(&nfulnl_subsys); @@ -1088,28 +1094,23 @@ static int __init nfnetlink_log_init(void) goto cleanup_subsys; } - status = register_pernet_subsys(&nfnl_log_net_ops); - if (status < 0) { - pr_err("failed to register pernet ops\n"); - goto cleanup_logger; - } return status; -cleanup_logger: - nf_log_unregister(&nfulnl_logger); cleanup_subsys: nfnetlink_subsys_unregister(&nfulnl_subsys); cleanup_netlink_notifier: netlink_unregister_notifier(&nfulnl_rtnl_notifier); + unregister_pernet_subsys(&nfnl_log_net_ops); +out: return status; } static void __exit nfnetlink_log_fini(void) { - unregister_pernet_subsys(&nfnl_log_net_ops); nf_log_unregister(&nfulnl_logger); nfnetlink_subsys_unregister(&nfulnl_subsys); netlink_unregister_notifier(&nfulnl_rtnl_notifier); + unregister_pernet_subsys(&nfnl_log_net_ops); } MODULE_DESCRIPTION("netfilter userspace logging"); diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index 0b98c7420239..11c7682fa0ea 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -1317,7 +1317,13 @@ static struct pernet_operations nfnl_queue_net_ops = { static int __init nfnetlink_queue_init(void) { - int status = -ENOMEM; + int status; + + status = register_pernet_subsys(&nfnl_queue_net_ops); + if (status < 0) { + pr_err("nf_queue: failed to register pernet ops\n"); + goto out; + } netlink_register_notifier(&nfqnl_rtnl_notifier); status = nfnetlink_subsys_register(&nfqnl_subsys); @@ -1326,19 +1332,13 @@ static int __init nfnetlink_queue_init(void) goto cleanup_netlink_notifier; } - status = register_pernet_subsys(&nfnl_queue_net_ops); - if (status < 0) { - pr_err("nf_queue: failed to register pernet ops\n"); - goto cleanup_subsys; - } register_netdevice_notifier(&nfqnl_dev_notifier); nf_register_queue_handler(&nfqh); return status; -cleanup_subsys: - nfnetlink_subsys_unregister(&nfqnl_subsys); cleanup_netlink_notifier: netlink_unregister_notifier(&nfqnl_rtnl_notifier); +out: return status; } @@ -1346,9 +1346,9 @@ static void __exit nfnetlink_queue_fini(void) { nf_unregister_queue_handler(); unregister_netdevice_notifier(&nfqnl_dev_notifier); - unregister_pernet_subsys(&nfnl_queue_net_ops); nfnetlink_subsys_unregister(&nfqnl_subsys); netlink_unregister_notifier(&nfqnl_rtnl_notifier); + unregister_pernet_subsys(&nfnl_queue_net_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ } -- cgit v1.2.3-59-g8ed1b