[PATCH nf,v6 3/4] netfilter: nf_tables: join hook list via splice_list_rcu() in commit phase

[Pablo Neira Ayuso <pablo@netfilter.org>]

Publish new hooks in the list into the basechain/flowtable using
splice_list_rcu() to ensure netlink dump list traversal via rcu is safe
while concurrent ruleset update is going on.

Fixes: 78d9f48f7f44 ("netfilter: nf_tables: add devices to existing flowtable")
Fixes: b9703ed44ffb ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v3: just a rebase on top of net-next, net is still behind.

 net/netfilter/nf_tables_api.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 07e151245765..ae10116af923 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -10838,8 +10838,8 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 				nft_chain_commit_update(nft_trans_container_chain(trans));
 				nf_tables_chain_notify(&ctx, NFT_MSG_NEWCHAIN,
 						       &nft_trans_chain_hooks(trans));
-				list_splice(&nft_trans_chain_hooks(trans),
-					    &nft_trans_basechain(trans)->hook_list);
+				list_splice_rcu(&nft_trans_chain_hooks(trans),
+						&nft_trans_basechain(trans)->hook_list);
 				/* trans destroyed after rcu grace period */
 			} else {
 				nft_chain_commit_drop_policy(nft_trans_container_chain(trans));
@@ -10968,8 +10968,8 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 							   nft_trans_flowtable(trans),
 							   &nft_trans_flowtable_hooks(trans),
 							   NFT_MSG_NEWFLOWTABLE);
-				list_splice(&nft_trans_flowtable_hooks(trans),
-					    &nft_trans_flowtable(trans)->hook_list);
+				list_splice_rcu(&nft_trans_flowtable_hooks(trans),
+						&nft_trans_flowtable(trans)->hook_list);
 			} else {
 				nft_clear(net, nft_trans_flowtable(trans));
 				nf_tables_flowtable_notify(&ctx,
-- 
2.47.3