Patch "netfilter: nf_tables: GC transaction race with abort path" has been added to the 6.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    netfilter: nf_tables: GC transaction race with abort path

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-nf_tables-gc-transaction-race-with-abort-p.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c5ae402fc5d60b333ec3f414dccf725b3221b6c7
Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date:   Fri Aug 18 01:13:52 2023 +0200

    netfilter: nf_tables: GC transaction race with abort path
    
    [ Upstream commit 720344340fb9be2765bbaab7b292ece0a4570eae ]
    
    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@xxxxxxxxxxxxx>
    Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 539bc5d5c12fd..9cd8c14a0faf4 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -10348,8 +10348,12 @@ 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;