This is a note to let you know that I've just added the patch titled netfilter: nft_payload: fix wrong mac header matching to the 6.1-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-nft_payload-fix-wrong-mac-header-matching.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d351c1ea2de3e36e608fc355d8ae7d0cc80e6cd6 Mon Sep 17 00:00:00 2001 From: Florian Westphal <fw@xxxxxxxxx> Date: Sun, 8 Oct 2023 19:36:53 +0200 Subject: netfilter: nft_payload: fix wrong mac header matching MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Florian Westphal <fw@xxxxxxxxx> commit d351c1ea2de3e36e608fc355d8ae7d0cc80e6cd6 upstream. mcast packets get looped back to the local machine. Such packets have a 0-length mac header, we should treat this like "mac header not set" and abort rule evaluation. As-is, we just copy data from the network header instead. Fixes: 96518518cc41 ("netfilter: add nftables") Reported-by: Blažej Krajňák <krajnak@xxxxxxxxxx> Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/netfilter/nft_payload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -132,7 +132,7 @@ void nft_payload_eval(const struct nft_e switch (priv->base) { case NFT_PAYLOAD_LL_HEADER: - if (!skb_mac_header_was_set(skb)) + if (!skb_mac_header_was_set(skb) || skb_mac_header_len(skb) == 0) goto err; if (skb_vlan_tag_present(skb)) { Patches currently in stable-queue which might be from fw@xxxxxxxxx are queue-6.1/netfilter-nft_payload-fix-wrong-mac-header-matching.patch