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>
---
This is already in the 5.y branches but 4.19 needs a minor
tweak as ->fragoff member resides in xt sub-struct.
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 b1a9f330a51f..fd87216bc0a9 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -194,6 +194,9 @@ static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt,
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);
--
2.34.1
