Subject: Re: [PATCH net-next 00/11] netfilter: updates for net-next

From: Florian Westphal <[email-masked]>
Date: Sun, 12 Apr 2026 19:17:22 +0200

Florian Westphal <[email-masked]> wrote:
> Jakub Kicinski <[email-masked]> wrote:
> https://sashiko.dev/#/patchset/20260410112352.23599-1-fw%40strlen.de

Forgot to mention this:

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AF_PACKET raw sockets or tun devices, the network_header might be
uninitialized (~0U). In this state, skb_mac_header_len() will evaluate to
a very large number, bypassing the ETH_HLEN check completely.
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Really?  TIL.

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Furthermore, skb_mac_header_len() only verifies the logical distance between
header offsets, rather than ensuring the bytes are actually present in the
physical linear buffer.

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Really?  Total news to me :-(