From cf0888acb562c94c517cb7472a2d17a11439f8f9 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Fri, 18 Aug 2023 00:38:56 +0200
Subject: [PATCH -stable,4.19 15/20] netfilter: nf_tables: GC transaction race
 with abort path

commit 720344340fb9be2765bbaab7b292ece0a4570eae upstream.

Abort path is missing a synchronization point with GC transactions. Add
GC sequence number hence any GC transaction losing race will be
discarded.

Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d49e2ef4cc3f..03100af9e096 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7206,7 +7206,12 @@ static int __nf_tables_abort(struct net *net)
 static int nf_tables_abort(struct net *net, struct sk_buff *skb)
 {
 	struct nftables_pernet *nft_net = net_generic(net, nf_tables_net_id);
-	int ret = __nf_tables_abort(net);
+	unsigned int gc_seq;
+	int ret;
+
+	gc_seq = nft_gc_seq_begin(nft_net);
+	ret = __nf_tables_abort(net);
+	nft_gc_seq_end(nft_net, gc_seq);
 
 	mutex_unlock(&nft_net->commit_mutex);
 
-- 
2.30.2

