From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C415037C934; Thu, 17 Sep 2026 01:55:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789610102; cv=none; b=QzJUEBnGR4JwPjEUdgmQUeWLBZykyATBc0BFcKtfdiDGZUpCvIRt2w9dkbMzTmZ1nLON7PVHVwGpZUrN+8cFvr2qDQUvtu+5/6IHt4wSVR6gk93XpfDloRCLgtTNNa+zZ4BJdYUxD7FJVjlLioEBEua9GcWIzln8wEoHv6Jn+qM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789610102; c=relaxed/simple; bh=2RJBx2RXmlO46GbKTUWo9mRYxlCy9WbMUTYFRRqKNQk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=UTlj8UKYpfRoRkmUhnU1FacfaVb8U9sXXCZiz6D5tTCQDY3aCX8ursuwT37TuRBIjMIIhN0KkATQse/8qOuYU+nA081LbgGkk3EIV/xfIs5th1Fe6IbhleWt7MEgubdACD35ONifZh6pyoCl9UYJumJVKHVe5fiqLpRVSguX+s8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hS77RQRK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hS77RQRK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D95471F000FF; Thu, 17 Sep 2026 01:55:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789610101; bh=AeRGnSVo/pZSPEvEnD0WVt6yfxZXDWoj6fvjGiYK9Fs=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=hS77RQRKPAPLL2kh/QY/7xBRrQA6JqaP6YPFbl9l8kOx6IbmmJXE8OBduRqruJJlf pJPA3T3XOt8sfkYdcNVnIn/214eTYsHwcwDr4ZZtTFLuKIrrPDu5Cgp4mvSPY5S1BT ZfJgzWhucsJQOXYnoEnCpIMg7mrcrGlhE5I0qXhTROR3kiH1IV3XTsjK99G8eCwfs6 Z+BfWu0bV4GzVl0eQQOsqE+Ldov4VLfC3aM3Y3ulReYyCbBNPrVzPtoq5hA1+pPo/l vjjTdBvukQVM1X95Oady4tAIzEYGy2LEcrTV41wi4Og2BcidJZHYhmSDOFR/8Gt8JF f8WcNbm2HDdOg== Date: Wed, 16 Sep 2026 18:55:00 -0700 From: Jakub Kicinski To: Farhad Alemi Cc: David Ahern , Ido Schimmel , "David S. Miller" , Eric Dumazet , Paolo Abeni , falemi@asu.edu, Simon Horman , Pablo Neira Ayuso , Florian Westphal , Lorenzo Bianconi , Xuanqiang Luo , netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net v2] net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check Message-ID: <20260916185500.1cfbf67e@kernel.org> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 12 Sep 2026 07:40:09 +0000 Farhad Alemi wrote: > ipip_fill_forward_path() and ip6_tnl_fill_forward_path() look up the > route to the tunnel's remote endpoint and set ctx->dev to its device, > which is the tunnel itself when that route resolves back to the tunnel. > dev_fill_forward_path() then makes no progress and trips > WARN_ON_ONCE(last_dev == ctx->dev) as soon as a flowtable tries to > offload a flow through the tunnel. That routing loop is a configuration > any CAP_NET_ADMIN user can set up, and ip_tunnel_xmit() and > ip6_tnl_xmit() already treat it as a tx error, so remove the warning and > just fail the walk, as commit 008e7a7c293b ("net: remove WARN_ON_ONCE > when accessing forward path array") did for the path stack overflow. > > Fixes: ab427db17885 ("netfilter: flowtable: Add IPIP rx sw acceleration") > Fixes: d98103575dcd ("netfilter: flowtable: Add IP6IP6 rx sw acceleration") > Closes: https://lore.kernel.org/all/CA+0ovCgaRvbd0Udj70b2xxG8Cx3CaCpNhnf1V4RWQuDveZYZhA@mail.gmail.com/ > Suggested-by: Pablo Neira Ayuso > Assisted-by: Claude:claude-opus-5 syzkaller > Signed-off-by: Farhad Alemi Applied as 150dba2c69e933 in net, thanks -- pw-bot: accept