netdev - [PATCH net 07/14] netfilter: nf_tables: Keep deleted flowtable hooks until after RCU

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Message-Id: <20240924201401.2712-8-pablo@netfilter.org>
Date: Tue, 24 Sep 2024 22:13:54 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net,
	netdev@...r.kernel.org,
	kuba@...nel.org,
	pabeni@...hat.com,
	edumazet@...gle.com,
	fw@...len.de
Subject: [PATCH net 07/14] netfilter: nf_tables: Keep deleted flowtable hooks until after RCU

From: Phil Sutter <phil@....cc>

Documentation of list_del_rcu() warns callers to not immediately free
the deleted list item. While it seems not necessary to use the
RCU-variant of list_del() here in the first place, doing so seems to
require calling kfree_rcu() on the deleted item as well.

Fixes: 3f0465a9ef02 ("netfilter: nf_tables: dynamically allocate hooks per net_device in flowtables")
Signed-off-by: Phil Sutter <phil@....cc>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 57259b5f3ef5..042080aeb46c 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9207,7 +9207,7 @@ static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable)
 		flowtable->data.type->setup(&flowtable->data, hook->ops.dev,
 					    FLOW_BLOCK_UNBIND);
 		list_del_rcu(&hook->list);
-		kfree(hook);
+		kfree_rcu(hook, rcu);
 	}
 	kfree(flowtable->name);
 	module_put(flowtable->data.type->owner);
-- 
2.30.2