From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Subject: [PATCH nf] netfilter: nft_payload: do not update layer 4 checksum when mangling fragments
Date: Wed, 5 Jan 2022 16:26:13 +0100 [thread overview]
Message-ID: <20220105152613.14133-1-pablo@netfilter.org> (raw)
IP fragments do not come with the transport header, hence skip bogus
layer 4 checksum updates.
Reported-by: Steffen Weinreich <steve@weinreich.org>
Tested-by: Steffen Weinreich <steve@weinreich.org>
Fixes: 1814096980bb ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
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 bd689938a2e0..58e96a0fe0b4 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);
--
2.30.2
reply other threads:[~2022-01-05 15:26 UTC|newest]
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