From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	 Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
	netdev@vger.kernel.org,  Ido Schimmel <idosch@nvidia.com>,
	David Ahern <dsahern@kernel.org>,
	eric.dumazet@gmail.com,  Eric Dumazet <edumazet@google.com>,
	"Ji'an Zhou" <eilaimemedsnaimel@gmail.com>,
	 Cong Wang <xiyou.wangcong@gmail.com>
Subject: [PATCH net] ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table()
Date: Thu, 21 May 2026 12:21:47 +0000	[thread overview]
Message-ID: <20260521122147.3584624-1-edumazet@google.com> (raw)

ipv4_sysctl_exit_net() is currently freeing net->ipv4.sysctl_local_reserved_ports
too soon.

Only after unregister_net_sysctl_table() we can be sure no threads can possibly
use the sysctls, including /proc/sys/net/ipv4/ip_local_reserved_ports.

Fixes: 122ff243f5f1 ("ipv4: make ip_local_reserved_ports per netns")
Reported-by: Ji'an Zhou <eilaimemedsnaimel@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
---
 net/ipv4/sysctl_net_ipv4.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index d8bdb1bdbff17ab52fe969b93ce13673e88c05a4..c0e85cc171aec099fd5d4897b1a623dd27eaee08 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -1705,10 +1705,10 @@ static __net_exit void ipv4_sysctl_exit_net(struct net *net)
 {
 	const struct ctl_table *table;
 
-	kfree(net->ipv4.sysctl_local_reserved_ports);
 	table = net->ipv4.ipv4_hdr->ctl_table_arg;
 	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
 	kfree(table);
+	kfree(net->ipv4.sysctl_local_reserved_ports);
 }
 
 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
-- 
2.54.0.669.g59709faab0-goog

next             reply	other threads:[~2026-05-21 12:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-21 12:21 Eric Dumazet [this message]
2026-05-21 13:13 ` [PATCH net] ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table() Jason Xing
2026-05-21 13:59 ` Jiayuan Chen
2026-05-21 14:39   ` Eric Dumazet
2026-05-23  2:20 ` patchwork-bot+netdevbpf

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