From: Jakub Kicinski <kuba@kernel.org>
To: Chris Arges <carges@cloudflare.com>
Cc: Weiming Shi <bestswngs@gmail.com>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
netdev@vger.kernel.org, kernel-team@cloudflare.com,
jgriege@cloudflare.com
Subject: Re: [REGRESSION] net: add xmit recursion limit to tunnel xmit functions
Date: Wed, 1 Apr 2026 17:38:43 -0700 [thread overview]
Message-ID: <20260401173843.7a2bb607@kernel.org> (raw)
In-Reply-To: <acwp_cVAflwTQCBh@20HS2G4>
On Tue, 31 Mar 2026 15:09:33 -0500 Chris Arges wrote:
> 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.
Last device meaning limit of 5 would have worked for you?
I don't think there was any hard math behind the 4 so ++
on the limit may be simplest, but I defer to Paolo..
next prev parent reply other threads:[~2026-04-02 0:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-31 20:09 [REGRESSION] net: add xmit recursion limit to tunnel xmit functions Chris Arges
2026-04-02 0:38 ` Jakub Kicinski [this message]
2026-04-02 9:31 ` Paolo Abeni
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