This is a note to let you know that I've just added the patch titled netfilter: nf_tables: release flow rule object from commit path to the 5.4-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-release-flow-rule-object-from-co.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7157f00ecfcf600e693bcfad2f96de7a7a5bffab Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Date: Wed Oct 26 09:54:45 2022 +0200 netfilter: nf_tables: release flow rule object from commit path [ Upstream commit 26b5934ff4194e13196bedcba373cd4915071d0e ] No need to postpone this to the commit release path, since no packets are walking over this object, this is accessed from control plane only. This helped uncovered UAF triggered by races with the netlink notifier. Fixes: 9dd732e0bdf5 ("netfilter: nf_tables: memleak flow rule from commit path") Reported-by: syzbot+8f747f62763bc6c32916@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index f9cecd30f1ba..140c24f1b6c6 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6576,9 +6576,6 @@ static void nft_commit_release(struct nft_trans *trans) nf_tables_chain_destroy(&trans->ctx); break; case NFT_MSG_DELRULE: - if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD) - nft_flow_rule_destroy(nft_trans_flow_rule(trans)); - nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans)); break; case NFT_MSG_DELSET: @@ -6913,6 +6910,9 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) nft_rule_expr_deactivate(&trans->ctx, nft_trans_rule(trans), NFT_TRANS_COMMIT); + + if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD) + nft_flow_rule_destroy(nft_trans_flow_rule(trans)); break; case NFT_MSG_NEWSET: nft_clear(net, nft_trans_set(trans));