5.15-stable review patch. If anyone has any objections, please let me know.
------------------
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
@@ -133,7 +133,7 @@ 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)) {
