[PATCH -stable,4.19.x 15/40] netfilter: nf_tables: GC transaction race with abort path

Pablo Neira Ayuso
2024-06-13T01:02:28Z

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 81bdc5201c91..a48e92114bdc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7263,7 +7263,12 @@ 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