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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAA85sZuGQGM+mNOtD+B=GQJjH3UaoqUkZkoeiKZ+ZD+7FR5ucQ@mail.gmail.com>
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?