netdev - Re: [PATCH net-next 3/4] ipv4: Reject routes specifying ECN bits in rtm

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

Message-ID: <d45370df-f752-bbcf-1fd1-ee52769c45c2@linuxfoundation.org>
Date:   Fri, 4 Feb 2022 11:19:43 -0700
From:   Shuah Khan <skhan@...uxfoundation.org>
To:     Guillaume Nault <gnault@...hat.com>,
        David Miller <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     netdev@...r.kernel.org,
        Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
        David Ahern <dsahern@...nel.org>,
        Toke Høiland-Jørgensen 
        <toke@...hat.com>, Shuah Khan <shuah@...nel.org>,
        linux-kselftest@...r.kernel.org,
        Russell Strong <russell@...ong.id.au>,
        Dave Taht <dave.taht@...il.com>,
        Shuah Khan <skhan@...uxfoundation.org>
Subject: Re: [PATCH net-next 3/4] ipv4: Reject routes specifying ECN bits in
 rtm_tos

On 2/4/22 6:58 AM, Guillaume Nault wrote:
> Use the new dscp_t type to replace the fc_tos field of fib_config, to
> ensure IPv4 routes aren't influenced by ECN bits when configured with
> non-zero rtm_tos.
> 
> Before this patch, IPv4 routes specifying an rtm_tos with some of the
> ECN bits set were accepted. However they wouldn't work (never match) as
> IPv4 normally clears the ECN bits with IPTOS_RT_MASK before doing a FIB
> lookup (although a few buggy code paths don't).
> 
> After this patch, IPv4 routes specifying an rtm_tos with any ECN bit
> set is rejected.
> 
> Note: IPv6 routes ignore rtm_tos altogether, any rtm_tos is accepted,
> but treated as if it were 0.
> 
> Signed-off-by: Guillaume Nault <gnault@...hat.com>
> ---
> Shuah, FYI, this is the patch I was refering to in our discussion about
> testing invalid tos values:
> https://lore.kernel.org/netdev/20220202232555.GC15826@pc-4.home/
> 

This give me context. Thank you.

thanks,
-- Shuah