netdev - Re: [PATCH net-next 15/17] udp: Set length in UDP header to 0 for big GSO packets

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: <7be5af09-2531-4b68-89af-106f90649bee@redhat.com>
Date: Thu, 25 Sep 2025 16:18:33 +0200
From: Paolo Abeni <pabeni@...hat.com>
To: Maxim Mikityanskiy <maxtram95@...il.com>,
 Daniel Borkmann <daniel@...earbox.net>, "David S. Miller"
 <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
 Jakub Kicinski <kuba@...nel.org>,
 Willem de Bruijn <willemdebruijn.kernel@...il.com>,
 David Ahern <dsahern@...nel.org>, Nikolay Aleksandrov <razor@...ckwall.org>
Cc: netdev@...r.kernel.org, tcpdump-workers@...ts.tcpdump.org,
 Guy Harris <gharris@...ic.net>, Michael Richardson <mcr@...delman.ca>,
 Denis Ovsienko <denis@...ienko.info>, Xin Long <lucien.xin@...il.com>,
 Maxim Mikityanskiy <maxim@...valent.com>
Subject: Re: [PATCH net-next 15/17] udp: Set length in UDP header to 0 for big
 GSO packets

On 9/23/25 3:47 PM, Maxim Mikityanskiy wrote:
> diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c
> index 54386e06a813..98faddb7b4bf 100644
> --- a/net/ipv4/udp_tunnel_core.c
> +++ b/net/ipv4/udp_tunnel_core.c
> @@ -184,7 +184,7 @@ void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb
>  
>  	uh->dest = dst_port;
>  	uh->source = src_port;
> -	uh->len = htons(skb->len);
> +	uh->len = skb->len <= GRO_LEGACY_MAX_SIZE ? htons(skb->len) : 0;

You could introduce a 'set' helper, and use it here and in patch 13/17

/P