From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f53.google.com (mail-wr1-f53.google.com [209.85.221.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9974D2798ED; Tue, 26 Aug 2025 12:11:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756210300; cv=none; b=S75qCEBbePhyQeImcbLkZv/P+dEa5+iFcesd7xT/Ta48CWiS2VmV0PjRtvGv2efkAFvyAQZ9rDO+XcG9tNVW/F+KQ41sIougObsgvZBRcqObN9jvBkyP5GiJ+IVwK8MfrL0kzN093cXgaXOhR9JbI5G64n3L5veKVlOpfqHExeM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756210300; c=relaxed/simple; bh=RhEbsQKmIX/lirH/uUzChufR/shylRIDYLkxgKJenr8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=C8dkTfjYtYYoXkBd0OoSQ5WMlNnrshM9L9UrV8RN7TFg5R89aMxvHxfvRcDJwVPdrHINh4jM3H4h82ZXXilhu+W0/CcXAayWaXFRqcj4658jPcaK3nOKwnkJLpQvolBo5ADLMWt9ZAtzIjSZ18HX7ATPjGq6vwArnS/eaAn9Zwc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=DtuuOliK; arc=none smtp.client-ip=209.85.221.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DtuuOliK" Received: by mail-wr1-f53.google.com with SMTP id ffacd0b85a97d-3c98b309804so1677204f8f.1; Tue, 26 Aug 2025 05:11:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1756210296; x=1756815096; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=bgo2eJak2Be9BA5zOK9ll3HUyMbKDaGl7xMwm/BsZe0=; b=DtuuOliKuY+8CUlHQ1yZiJ+WNTG9gNRXTUh3IC7oZK4EMOVmcxhEXYFnrdjUcf8mLN QPtkt7U16qCOX/8Ycb3tVnHKsbp0iekFl/j5CRZo07JHhs43q8W38peheiMm8BKTcRka avSZhkGD/EIdymf17UBub+VMu2CSQGaeX4cIFYFbiLDNJ3iOqwoP2BP0zMXu49bvE3cf m/fIctlvimbgGnICPgseJsKw6CwL7aaWQnJDxUtlPFB8as9JTdiMT9GEABF2FVjt1yUk LklbHs0WUkiEzG6yBSVwOoAzq2mflBE0FECInOopWx8vFrEwSUA8aNEWrHSbrP8rcNQS 19vA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756210296; x=1756815096; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=bgo2eJak2Be9BA5zOK9ll3HUyMbKDaGl7xMwm/BsZe0=; b=sbB12946ZaX87jev6iGdSwvkhsGLG4f7HwFE0KV1+2VwgLtWf7Mvj/mg+ubPTeJr+O 8JHXcDEXTnrqLUMkQBQm58StUWqWTJyMULObbcq7Z3KfGhh9msDrBVinLRm2cAJT6csy tH+gRaYC+bm19my/Zjr5WQxoWQ2ktVm7ITKoXiFezns9QIrPSVhh/1quDUNXLXlTDDPF vyEsWU6GnNml/fEfe2eUCxS++hdKU+R6sgYLyH7mfASWLYPD3dOJL0b2bHGAqrPKzg7K F6Xbp1O+TqZ5NYLLrWkQoAiZPjwNCxV9zVydHu0W+0IDF3x0pGKh6mnGbXk9Gk6ImEjA AJzg== X-Forwarded-Encrypted: i=1; AJvYcCVgtZWCRTZ7s4Jnl9mtu0PKgNuXp9JFuPBCwbh/7Ioq7v1100mbhtBiw1BETe3aQeP5wJeb3dl4@vger.kernel.org, AJvYcCXWt/cY6VfbPUVo2vFm9XDuTV0H9cdOp5zFmqejhzNs1qqbbG11hkBAA1m7CYLiQY/eKBrRUZo=@vger.kernel.org X-Gm-Message-State: AOJu0Yy6bT3oIpy0n1ptwtSmIkGw4bQTwvv3pJouxvX0FzKyVOoceA4T EK0H/t4raA94MIyE8YeiBCqpiPdqBzze/qwjpV86wlt2feZQBKXwI+Fq5OCBonnO X-Gm-Gg: ASbGncsi+uUj5gUHtdLmNh8EtjG84d6KxlrNsa+rMjGX8UJaiuGHPz8SlEwjYzX1cob ufeDH1J/ioRfFKowimq7A4ii2Ox7nQ0tY7/m6CSVwpgnRN0myz4ofaW28DUMzvxHHf61gFhJNka MbTw1H1xMh/H4KYQ5H+Iyj5RRsfr6OMxDXrbtvA0sgsOg2r7u3QBOqYZSvAd6pMi569Eh7lmd/t qplIbJlSrvfkGfHDsFeDptndNp4xLw1DVMK9sg6NrjKGHuUGrSPsoHR1YQfA4Lg8DzbSpGVUT3b cmb0Q96EpCGbVS0B3nmoQ07Gedam14vEOm/l0R5yw6jQMtMAV3V3nXXzd/Efc7uBCeHcZ144MM2 78C9fEX71IdBGzsPwxEV8tUThQEYCNlLBk/Q= X-Google-Smtp-Source: AGHT+IFyt1noHdTU+Lxyu4hFFrhdSpjqHvjbZWL24i076P4M6ZzzL90XYNqTJ7uxCxOxl+awWvRnUA== X-Received: by 2002:a05:6000:24c9:b0:3b7:93d3:f478 with SMTP id ffacd0b85a97d-3c5dce01212mr12959641f8f.51.1756210295606; Tue, 26 Aug 2025 05:11:35 -0700 (PDT) Received: from localhost.localdomain ([45.128.133.231]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3c711211e87sm15670520f8f.44.2025.08.26.05.11.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Aug 2025 05:11:35 -0700 (PDT) Date: Tue, 26 Aug 2025 14:11:26 +0200 From: Oscar Maes To: Jakub Kicinski Cc: bacs@librecast.net, brett@librecast.net, davem@davemloft.net, dsahern@kernel.org, netdev@vger.kernel.org, regressions@lists.linux.dev, stable@vger.kernel.org Subject: Re: [PATCH net 1/2] net: ipv4: fix regression in local-broadcast routes Message-ID: <20250826121126-oscmaes92@gmail.com> References: <20250825060229-oscmaes92@gmail.com> <20250825060918.4799-1-oscmaes92@gmail.com> <20250825155630.5848c357@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250825155630.5848c357@kernel.org> On Mon, Aug 25, 2025 at 03:56:30PM -0700, Jakub Kicinski wrote: > On Mon, 25 Aug 2025 08:09:17 +0200 Oscar Maes wrote: > > Commit 9e30ecf23b1b ("net: ipv4: fix incorrect MTU in broadcast routes") > > introduced a regression where local-broadcast packets would have their > > gateway set in __mkroute_output, which was caused by fi = NULL being > > removed. > > > > Fix this by resetting the fib_info for local-broadcast packets. > > Meaning that 9e30ecf23b1b would still change behavior for the subnet > broadcast address? > Yes. This is OK because subnet broadcast addresses have separate entries in the local fib table. > > diff --git a/net/ipv4/route.c b/net/ipv4/route.c > > index f639a2ae881a..98d237e3ec04 100644 > > --- a/net/ipv4/route.c > > +++ b/net/ipv4/route.c > > @@ -2575,9 +2575,12 @@ static struct rtable *__mkroute_output(const struct fib_result *res, > > !netif_is_l3_master(dev_out)) > > return ERR_PTR(-EINVAL); > > > > - if (ipv4_is_lbcast(fl4->daddr)) > > + if (ipv4_is_lbcast(fl4->daddr)) { > > type = RTN_BROADCAST; > > - else if (ipv4_is_multicast(fl4->daddr)) > > + > > + /* reset fi to prevent gateway resolution */ > > + fi = NULL; > > + } else if (ipv4_is_multicast(fl4->daddr)) > > type = RTN_MULTICAST; > > else if (ipv4_is_zeronet(fl4->daddr)) > > return ERR_PTR(-EINVAL); > > nit: please add curly braces around all branches of this if / else if / > else ladder, per kernel coding style guide. > -- > pw-bot: cr