netdev - IP oversized ip oacket from - header size should be skipped?

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Date: Fri, 28 Jun 2024 11:30:48 +0200
From: Ian Kumlien <ian.kumlien@...il.com>
To: Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: IP oversized ip oacket from - header size should be skipped?

Hi,

In net/ipv4/ip_fragment.c line 412:
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
                         struct sk_buff *prev_tail, struct net_device *dev)
{
...
        len = ip_hdrlen(skb) + qp->q.len;
        err = -E2BIG;
        if (len > 65535)
                goto out_oversize;
....

We can expand the expression to:
len = (ip_hdr(skb)->ihl * 4) + qp->q.len;

But it's still weird since the definition of q->len is: "total length
of the original datagram"
Which should mean that we are comparing total length + ip header size
instead of just total length?