[PATCH nf,v2 1/2] netfilter: nf_tables: hold mutex on netns pre_exit path

[Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>]

clean_net() runs in workqueue while walking over the lists, grab mutex.

Fixes: 767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
v2: missing in initial submission.

 net/netfilter/nf_tables_api.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3c7fab36133b..2c6c956c7bbc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9882,7 +9882,11 @@ static int __net_init nf_tables_init_net(struct net *net)
 
 static void __net_exit nf_tables_pre_exit_net(struct net *net)
 {
+	struct nftables_pernet *nft_net = nft_pernet(net);
+
+	mutex_lock(&nft_net->commit_mutex);
 	__nft_release_hooks(net);
+	mutex_unlock(&nft_net->commit_mutex);
 }
 
 static void __net_exit nf_tables_exit_net(struct net *net)
-- 
2.30.2