[SRU Jammy, OEM-6.0, OEM-6.1, Lunar] netfilter: nf_tables: GC transaction race with abort path

[Cengiz Can]

From: Pablo Neira Ayuso <pablo at netfilter.org>

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 at netfilter.org>
Signed-off-by: Florian Westphal <fw at strlen.de>
(cherry picked from commit 720344340fb9be2765bbaab7b292ece0a4570eae)
CVE-2023-4244
[cengizcan: fixes the fix commit]
Signed-off-by: Cengiz Can <cengiz.can at canonical.com>
---
 net/netfilter/nf_tables_api.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 13912f504776..10646308b06d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9886,8 +9886,12 @@ static int nf_tables_abort(struct net *net, struct sk_buff *skb,
 			   enum nfnl_abort_action action)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
-	int ret = __nf_tables_abort(net, action);
+	unsigned int gc_seq;
+	int ret;
 
+	gc_seq = nft_gc_seq_begin(nft_net);
+	ret = __nf_tables_abort(net, action);
+	nft_gc_seq_end(nft_net, gc_seq);
 	mutex_unlock(&nft_net->commit_mutex);
 
 	return ret;
-- 
2.39.2