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([2a09:bac6:bf21:2e28::499:30]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-422eaf2c780sm3424927fac.6.2026.04.02.15.24.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Apr 2026 15:24:16 -0700 (PDT) From: Chris J Arges To: pabeni@redhat.com, bestswngs@gmail.com Cc: kernel-team@cloudflare.com, Chris J Arges , "David S. Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] net: increase IP_TUNNEL_RECURSION_LIMIT to 5 Date: Thu, 2 Apr 2026 17:23:16 -0500 Message-ID: <20260402222401.3408368-1-carges@cloudflare.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In configurations with multiple tunnel layers and MPLS lwtunnel routing, a single tunnel hop can increment the counter beyond this limit. This causes packets to be dropped with the "Dead loop on virtual device" message even when a routing loop doesn't exist. Increase IP_TUNNEL_RECURSION_LIMIT from 4 to 5 to handle this use-case. Fixes: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit function= s") Link: https://lore.kernel.org/netdev/88deb91b-ef1b-403c-8eeb-0f971f27e34f@r= edhat.com/ Signed-off-by: Chris J Arges --- include/net/ip_tunnels.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 1f577a4f8ce9..d708b66e55cd 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -32,7 +32,7 @@ * recursion involves route lookups and full IP output, consuming much * more stack per level, so a lower limit is needed. */ -#define IP_TUNNEL_RECURSION_LIMIT 4 +#define IP_TUNNEL_RECURSION_LIMIT 5 =20 /* Keep error state on tunnel for 30 sec */ #define IPTUNNEL_ERR_TIMEO (30*HZ) --=20 2.43.0