netdev - Re: [PATCH net v2] udp: Compute L4 checksum as usual when not segmenting the skb

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: <670931a2edb62_234aca29433@willemb.c.googlers.com.notmuch>
Date: Fri, 11 Oct 2024 10:09:38 -0400
From: Willem de Bruijn <willemdebruijn.kernel@...il.com>
To: Jakub Sitnicki <jakub@...udflare.com>, 
 Willem de Bruijn <willemdebruijn.kernel@...il.com>, 
 "David S. Miller" <davem@...emloft.net>, 
 David Ahern <dsahern@...nel.org>, 
 Eric Dumazet <edumazet@...gle.com>, 
 Jakub Kicinski <kuba@...nel.org>, 
 Paolo Abeni <pabeni@...hat.com>
Cc: netdev@...r.kernel.org, 
 kernel-team@...udflare.com, 
 Ivan Babrou <ivan@...udflare.com>, 
 Jakub Sitnicki <jakub@...udflare.com>, 
 stable@...r.kernel.org
Subject: Re: [PATCH net v2] udp: Compute L4 checksum as usual when not
 segmenting the skb

Jakub Sitnicki wrote:
> If:
> 
>   1) the user requested USO, but
>   2) there is not enough payload for GSO to kick in, and
>   3) the egress device doesn't offer checksum offload, then
> 
> we want to compute the L4 checksum in software early on.
> 
> In the case when we are not taking the GSO path, but it has been requested,
> the software checksum fallback in skb_segment doesn't get a chance to
> compute the full checksum, if the egress device can't do it. As a result we
> end up sending UDP datagrams with only a partial checksum filled in, which
> the peer will discard.
> 
> Fixes: 10154dbded6d ("udp: Allow GSO transmit from devices with no checksum offload")
> Reported-by: Ivan Babrou <ivan@...udflare.com>
> Signed-off-by: Jakub Sitnicki <jakub@...udflare.com>
> Acked-by: Willem de Bruijn <willemdebruijn.kernel@...il.com>
> Cc: stable@...r.kernel.org

You already included my Acked-by, but just to confirm: LGTM.