4.19-stable review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
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@levonet.sk Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -84,7 +84,7 @@ static void nft_payload_eval(const struc
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)) {