From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D06B6C433EF for ; Mon, 14 Feb 2022 07:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236842AbiBNHoT (ORCPT ); Mon, 14 Feb 2022 02:44:19 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:58910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235718AbiBNHoS (ORCPT ); Mon, 14 Feb 2022 02:44:18 -0500 Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B4645A59E for ; Sun, 13 Feb 2022 23:44:10 -0800 (PST) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id D40F65C00F2; Mon, 14 Feb 2022 02:44:07 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute2.internal (MEProxy); Mon, 14 Feb 2022 02:44:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=4dSVolvJBKEgqDGgP djwbbEgmtJVcyb7tHJDTHg95ko=; b=C21JRaAGTlsqW9Oid/ss47GnL4rJwL/bY q+gxGRj/sLuceSQCgl1J3XgwkLm3xcH6n8D2ueFlV3uChy1FkMoSd9IT3f8xLQzJ cJSUVm/ENPnxEYQDJ4sWqQavibkQAsOOM5HaeEgbWuj6+LuCNrjCm4jDcwlk00me RHEUNJezHI6oAJ+lSenfiwIOaBjULQq35Et6Bop+rFdpy7djdvl8va2rsiV2p2U9 bubW+85VXubzxeN/F/iwW+h+r05GPJwxZ1f4d1U1ovbDjDBEzS00rf0K4GE8DPxT cZyRS6V2qOau6W6VKYVKwCU+QxGejGb8cdRdww5869AEiWBGyWNyw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrjedugdduuddtucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefkughoucfu tghhihhmmhgvlhcuoehiughoshgthhesihguohhstghhrdhorhhgqeenucggtffrrghtth gvrhhnpedtffekkeefudffveegueejffejhfetgfeuuefgvedtieehudeuueekhfduheel teenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehiug hoshgthhesihguohhstghhrdhorhhg X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 14 Feb 2022 02:44:06 -0500 (EST) Date: Mon, 14 Feb 2022 09:44:02 +0200 From: Ido Schimmel To: Eric Dumazet Cc: "David S . Miller" , Jakub Kicinski , netdev , Eric Dumazet , Ido Schimmel , syzbot Subject: Re: [PATCH net-next] ipv6: blackhole_netdev needs snmp6 counters Message-ID: References: <20220214021056.389298-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220214021056.389298-1-eric.dumazet@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Feb 13, 2022 at 06:10:56PM -0800, Eric Dumazet wrote: > From: Ido Schimmel > > Whenever rt6_uncached_list_flush_dev() swaps rt->rt6_idev > to the blackhole device, parts of IPv6 stack might still need > to increment one SNMP counter. > > Root cause, patch from Ido, changelog from Eric :) > > This bug suggests that we need to audit rt->rt6_idev usages > and make sure they are properly using RCU protection. > > Fixes: e5f80fcf869a ("ipv6: give an IPv6 dev to blackhole_netdev") > Signed-off-by: Ido Schimmel > Signed-off-by: Eric Dumazet > Reported-by: syzbot Thanks for taking care of this, Eric. I applied the patch to our tree last night before logging off and regression does look fine.