From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>, bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, davem@davemloft.net,
edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch,
horms@kernel.org, Jakub Kicinski <kuba@kernel.org>,
maze@google.com, willemdebruijn.kernel@gmail.com,
ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org,
yonghong.song@linux.dev, john.fastabend@gmail.com,
kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com,
jolsa@kernel.org
Subject: Re: [PATCH bpf-next v2 1/2] net: clear the dst when performing encap / decap
Date: Mon, 30 Mar 2026 09:42:26 -0400 [thread overview]
Message-ID: <willemdebruijn.kernel.15a62f8f2870@gmail.com> (raw)
In-Reply-To: <20260329180428.2657785-1-kuba@kernel.org>
Jakub Kicinski wrote:
> Commit ba9db6f907ac ("net: clear the dst when changing skb protocol")
> added dst clearing when a BPF program changes the skb protocol
> (e.g. IPv4 to IPv6). Since that was a fix we only cleared the dst when
> the L3 protocol actually changes to keep it minimal. As suggested during
> the discussion (see Link) encap or decap operation which wraps or unwraps
> a same-protocol header may also render the existing dst incorrect - even
> if that doesn't result in a crash, just the wrong route for the now-outermost
> IP dst.
>
> Make dropping dst unconditional for bpf_skb_change_proto() and all
> L3 encap / decap ops.
>
> Link: https://lore.kernel.org/CANP3RGfRaYwve_xgxH6Tp2zenzKn2-DjZ9tg023WVzfdJF3p_w@mail.gmail.com
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
next prev parent reply other threads:[~2026-03-30 13:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-29 18:04 [PATCH bpf-next v2 1/2] net: clear the dst when performing encap / decap Jakub Kicinski
2026-03-29 18:04 ` [PATCH bpf-next v2 2/2] selftests/bpf: test that dst is cleared on same-protocol encap Jakub Kicinski
2026-03-30 8:03 ` Daniel Borkmann
2026-03-30 23:29 ` Jakub Kicinski
2026-03-31 0:29 ` Martin KaFai Lau
2026-03-30 7:48 ` [PATCH bpf-next v2 1/2] net: clear the dst when performing encap / decap Daniel Borkmann
2026-03-30 13:42 ` Willem de Bruijn [this message]
2026-03-30 22:20 ` 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.15a62f8f2870@gmail.com \
--to=willemdebruijn.kernel@gmail.com \
--cc=andrew+netdev@lunn.ch \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=eddyz87@gmail.com \
--cc=edumazet@google.com \
--cc=haoluo@google.com \
--cc=horms@kernel.org \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=martin.lau@linux.dev \
--cc=maze@google.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sdf@fomichev.me \
--cc=song@kernel.org \
--cc=yonghong.song@linux.dev \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox