From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> commit 4e1860a3863707e8177329c006d10f9e37e097a8 upstream. IP fragments do not come with the transport header, hence skip bogus layer 4 checksum updates. Fixes: 1814096980bb ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields") Reported-and-tested-by: Steffen Weinreich <steve@xxxxxxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/netfilter/nft_payload.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -502,6 +502,9 @@ static int nft_payload_l4csum_offset(con 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);