From: Florian Westphal <fw@strlen.de>
To: <netfilter-devel@vger.kernel.org>
Cc: Florian Westphal <fw@strlen.de>
Subject: [PATCH nf] netfilter: nf_reject: skip iphdr options when looking for icmp header
Date: Thu, 18 Jun 2026 10:49:24 +0200 [thread overview]
Message-ID: <20260618084927.2659-1-fw@strlen.de> (raw)
Not a big deal but this hould have used the real ip header length and not the
base header size. As-is, if there are options then
nf_skb_is_icmp_unreach() result will be random.
Fixes: db99b2f2b3e2 ("netfilter: nf_reject: don't reply to icmp error messages")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
net/ipv4/netfilter/nf_reject_ipv4.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index fecf6621f679..4626dc46808f 100644
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -89,7 +89,7 @@ static bool nf_skb_is_icmp_unreach(const struct sk_buff *skb)
if (iph->protocol != IPPROTO_ICMP)
return false;
- thoff = skb_network_offset(skb) + sizeof(*iph);
+ thoff = skb_network_offset(skb) + ip_hdrlen(skb);
tp = skb_header_pointer(skb,
thoff + offsetof(struct icmphdr, type),
--
2.53.0
reply other threads:[~2026-06-18 8:49 UTC|newest]
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