From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Eric Dumazet <edumazet@kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
David Ahern <dsahern@kernel.org>,
Ido Schimmel <idosch@nvidia.com>,
netdev@vger.kernel.org, edumazet@google.com,
Eric Dumazet <edumazet@kernel.org>,
Jiayuan Chen <jiayuan.chen@linux.dev>,
Willem de Bruijn <willemb@google.com>
Subject: Re: [PATCH v2 net 2/2] ipv4: reserve one IP ID per segment for UDP GSO packets
Date: Wed, 30 Sep 2026 11:12:29 -0400 [thread overview]
Message-ID: <willemdebruijn.kernel.1713efd699025@gmail.com> (raw)
In-Reply-To: <20260930144018.1174068-3-edumazet@kernel.org>
Eric Dumazet wrote:
> __ip_make_skb() reserves a single IP ID for UDP GSO packets, but GSO
> assigns one IP ID per segment. Following packets then reuse these IDs,
> either from inet->inet_id or from the shared generator.
>
> Unless IP_PMTUDISC_DO/PROBE is used, DF is not set on UDP GSO packets,
> so segments can be fragmented on the path and IP ID reuse can lead to
> incorrect reassembly.
>
> Reserve one IP ID per segment, using the same test as udp_send_skb().
>
> Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
> Signed-off-by: Eric Dumazet <edumazet@kernel.org>
> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
> Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
next prev parent reply other threads:[~2026-09-30 15:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-30 14:40 [PATCH v2 net 0/2] ipv4: fix IP ID reuse for GSO packets Eric Dumazet
2026-09-30 14:40 ` [PATCH v2 net 1/2] ipv4: fix IP ID reuse in ip_select_ident_segs() Eric Dumazet
2026-09-30 15:11 ` Willem de Bruijn
2026-09-30 14:40 ` [PATCH v2 net 2/2] ipv4: reserve one IP ID per segment for UDP GSO packets Eric Dumazet
2026-09-30 15:12 ` Willem de Bruijn [this message]
2026-10-05 22:10 ` [PATCH v2 net 0/2] ipv4: fix IP ID reuse for " patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=willemdebruijn.kernel.1713efd699025@gmail.com \
--to=willemdebruijn.kernel@gmail.com \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=edumazet@kernel.org \
--cc=horms@kernel.org \
--cc=idosch@nvidia.com \
--cc=jiayuan.chen@linux.dev \
--cc=kuba@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=willemb@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.