From 30e1740ed1d60a306a643f82de04c1754bf3b477 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 5 Jan 2022 16:09:57 +0100 Subject: [PATCH] netfilter: nft_payload: do not update layer 4 checksum when mangling fragments IP fragments do not come with the transport header, hence skip bogus layer 4 checksum updates. Fixes: 027bee253306 ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields") Reported-and-tested-by: Steffen Weinreich Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index bd689938a2e0c..58e96a0fe0b4c 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -546,6 +546,9 @@ static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt, struct sk_buff *skb, unsigned int *l4csum_offset) { + if (pkt->fragoff) + return -1; + switch (pkt->tprot) { case IPPROTO_TCP: *l4csum_offset = offsetof(struct tcphdr, check); -- 2.39.5