From c83fa19603bdaeef17b815713dbbe3230c8a34ee Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 25 Apr 2017 10:24:03 +0200 Subject: [PATCH 1/1] netfilter: nf_log: don't call synchronize_rcu in nf_log_unset nf_log_unregister() (which is what gets called in the logger backends module exit paths) does a (required, module is removed) synchronize_rcu(). But nf_log_unset() is only called from pernet exit handlers. It doesn't free any memory so there appears to be no need to call synchronize_rcu. v2: Liping Zhang points out that nf_log_unregister() needs to be called after pernet unregister, else rmmod would become unsafe. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_log.c | 1 - net/netfilter/nfnetlink_log.c | 2 +- 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c index cc32727e3f32..8bb152a7cca4 100644 --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -71,7 +71,6 @@ void nf_log_unset(struct net *net, const struct nf_logger *logger) RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL); } mutex_unlock(&nf_log_mutex); - synchronize_rcu(); } EXPORT_SYMBOL(nf_log_unset); diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 896741206a50..da9704971a83 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -1140,10 +1140,10 @@ out: static void __exit nfnetlink_log_fini(void) { - nf_log_unregister(&nfulnl_logger); nfnetlink_subsys_unregister(&nfulnl_subsys); netlink_unregister_notifier(&nfulnl_rtnl_notifier); unregister_pernet_subsys(&nfnl_log_net_ops); + nf_log_unregister(&nfulnl_logger); } MODULE_DESCRIPTION("netfilter userspace logging"); -- 2.39.2