Hi! >> Regarding 4.19, the patch does not work there since the struct pkt does >> not have a member fragoff. I suppose this is hidden deeply in the skbuf >> structure... > Sad. You might ask the maintainers if they can consider the fix as > well for older stable series, mentioneing back the one you would be > intersted in (so 4.19.y in your case).
Thanks to a hint from Florian Westphal, i modified the patch for 4.19 and it fixes the issue also in 4.19. The patch is attached. cheerio Steve
--- linux-source-4.19/net/netfilter/nft_payload.c.orig 2021-09-26 11:39:49.000000000 +0000 +++ linux-source-4.19/net/netfilter/nft_payload.c 2022-01-04 18:53:04.888219213 +0000 @@ -194,6 +194,9 @@ struct sk_buff *skb, unsigned int *l4csum_offset) { + if (pkt->xt.fragoff) + return -1; + switch (pkt->tprot) { case IPPROTO_TCP: *l4csum_offset = offsetof(struct tcphdr, check);