All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chris Arges <carges@cloudflare.com>
To: Weiming Shi <bestswngs@gmail.com>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com,
	jgriege@cloudflare.com
Subject: [REGRESSION] net: add xmit recursion limit to tunnel xmit functions
Date: Tue, 31 Mar 2026 15:09:33 -0500	[thread overview]
Message-ID: <acwp_cVAflwTQCBh@20HS2G4> (raw)

Hello,

Commit 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions")
introduces a regression in our systems using legitimate multi-level tunnel
encapsulation stacks. Our testing was with stable 6.12.y and 6.18.y where this
patch was backported.

One of the usecases we have are packets being sent to a GRE device, then
MPLS/LWT route, then IPIP device, then SIT/FOU device. What we observed is that
packets are getting dropped at the last device and we get the message "Dead
loop on virtual device" sent from the iptunnel_xmit function.

I'm looking for some approaches to retain the mitigation while still having a
recursion limit. One idea is to just increase the limit. Happy to provide
additional testing and debugging.

Thanks,
--chris

             reply	other threads:[~2026-03-31 20:09 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-31 20:09 Chris Arges [this message]
2026-04-02  0:38 ` [REGRESSION] net: add xmit recursion limit to tunnel xmit functions Jakub Kicinski
2026-04-02  9:31   ` Paolo Abeni

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=acwp_cVAflwTQCBh@20HS2G4 \
    --to=carges@cloudflare.com \
    --cc=bestswngs@gmail.com \
    --cc=edumazet@google.com \
    --cc=jgriege@cloudflare.com \
    --cc=kernel-team@cloudflare.com \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.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.