6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal [ Upstream commit 33d1469b0124cc0baaea7a2032123b77a81e0940 ] sashiko reports: "nfnl_log_net_exit() calls nf_log_unset(), which clears the logger pointer without an RCU grace period. Immediately after, ops_free_list() frees the per-net state while concurrent packets might still be executing nf_log_packet() under rcu_read_lock()." Clear the pointer via .pre_exit to make sure rcu readers have completed before pernet storage is free'd. The change in nf_log_syslog.c is only done for consistency: it doesn't use pernet data. Link: https://sashiko.dev/#/patchset/20260731151806.849724-1-pablo%40netfilter.org Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_log_syslog.c | 4 ++-- net/netfilter/nfnetlink_log.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c index 11325bad19b36..70bac3f45a015 100644 --- a/net/netfilter/nf_log_syslog.c +++ b/net/netfilter/nf_log_syslog.c @@ -1004,7 +1004,7 @@ static int __net_init nf_log_syslog_net_init(struct net *net) return ret; } -static void __net_exit nf_log_syslog_net_exit(struct net *net) +static void __net_exit nf_log_syslog_net_pre_exit(struct net *net) { nf_log_unset(net, &nf_ip_logger); nf_log_unset(net, &nf_arp_logger); @@ -1015,7 +1015,7 @@ static void __net_exit nf_log_syslog_net_exit(struct net *net) static struct pernet_operations nf_log_syslog_net_ops = { .init = nf_log_syslog_net_init, - .exit = nf_log_syslog_net_exit, + .pre_exit = nf_log_syslog_net_pre_exit, }; static int __init nf_log_syslog_init(void) diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 3da32d2f68e09..5df1d197f07d2 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -1137,21 +1137,26 @@ static int __net_init nfnl_log_net_init(struct net *net) return 0; } -static void __net_exit nfnl_log_net_exit(struct net *net) +static void __net_exit nfnl_log_net_pre_exit(struct net *net) { - struct nfnl_log_net *log = nfnl_log_pernet(net); - unsigned int i; - #ifdef CONFIG_PROC_FS remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter); #endif nf_log_unset(net, &nfulnl_logger); +} + +static void __net_exit nfnl_log_net_exit(struct net *net) +{ + struct nfnl_log_net *log = nfnl_log_pernet(net); + unsigned int i; + for (i = 0; i < INSTANCE_BUCKETS; i++) WARN_ON_ONCE(!hlist_empty(&log->instance_table[i])); } static struct pernet_operations nfnl_log_net_ops = { .init = nfnl_log_net_init, + .pre_exit = nfnl_log_net_pre_exit, .exit = nfnl_log_net_exit, .id = &nfnl_log_net_id, .size = sizeof(struct nfnl_log_net), -- 2.53.0