netdev - Re: [PATCH net] net:ipv6: Discard next-hop MTU less than minimum link MTU

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-prev] [day] [month] [year] [list]

Message-ID: <20201009162332.3bbdd556@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
Date:   Fri, 9 Oct 2020 16:23:32 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Georg Kohmann <geokohma@...co.com>
Cc:     netdev@...r.kernel.org, davem@...emloft.net, kuznet@....inr.ac.ru,
        yoshfuji@...ux-ipv6.org
Subject: Re: [PATCH net] net:ipv6: Discard next-hop MTU less than minimum
 link MTU

On Wed,  7 Oct 2020 14:53:02 +0200 Georg Kohmann wrote:
> When a ICMPV6_PKT_TOOBIG report a next-hop MTU that is less than the IPv6
> minimum link MTU, the estimated path MTU is reduced to the minimum link
> MTU. This behaviour breaks TAHI IPv6 Core Conformance Test v6LC4.1.6:
> Packet Too Big Less than IPv6 MTU.
> 
> Referring to RFC 8201 section 4: "If a node receives a Packet Too Big
> message reporting a next-hop MTU that is less than the IPv6 minimum link
> MTU, it must discard it. A node must not reduce its estimate of the Path
> MTU below the IPv6 minimum link MTU on receipt of a Packet Too Big
> message."
> 
> Drop the path MTU update if reported MTU is less than the minimum link MTU.
> 
> Signed-off-by: Georg Kohmann <geokohma@...co.com>

Applied, thank you!