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 EA9BFC433F5 for ; Tue, 25 Jan 2022 03:15:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1319932AbiAYDJ5 (ORCPT ); Mon, 24 Jan 2022 22:09:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1313536AbiAYCss (ORCPT ); Mon, 24 Jan 2022 21:48:48 -0500 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 336A1C061747; Mon, 24 Jan 2022 16:04:43 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id p15so26021298ejc.7; Mon, 24 Jan 2022 16:04:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=W71C0v5EvF5HVGKANsilC3VZ/yenGYfwtXQzi/osySw=; b=XglpY4J70hESr9fn8wrqXu8tX4R8GzwrZqkhwstzBzA75O4FsethTLOMOp4fXWlvKe sVWtKliLJl2YKRt4CXb1g9DPBpEMxJGA9DBr6oYCwDpQ/aibJB1IIpzFJX9EgQbnWF0z gWp3HT6XH+Gc3+3y/X+mTyH40FoN/TpRq4JLBgQ6UZJso+vP28uz6p0O/P5pBybo8pBz lrP21YQ98ByoEIGvu5guoLgNGPAacnTlnstwhl2novNzmyrXI/RgeYGNQuStJKIpf4Ej IMRIOpT9lt7IiN8gdMlSChanWXBe78gNVEMSUi/4qQSdc7pP7SgdVpnugWIIU+zm8YJv 8E+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=W71C0v5EvF5HVGKANsilC3VZ/yenGYfwtXQzi/osySw=; b=rPwF4J2E3RRoS/FuM3cz40TI0oI1zzzzMnaRjClWfoGAM7imiWAwX7ooWosbvtyGfe D3sOuDVBLc4SfrvKcOArGeTyvvjuScUern9inDZ/OvSjcpZ8a+FD2VdLjMZS2Y09DFNJ WPsgiU3NCkXHihWVrB62OM5Z7uPtDeBDDWZfYBEN9xHyY0wSsXS/2nDL//Ha9GQP/sdT 86o+BaY8n6lSEFNJ2fIDM8862+eFgrbvGrIt5yW6zVDgzuItHFQonSLPTS+XVZLqH43w +Y6z4C5B5QfDsvvCz7t3oifugL7r9GUN6UfqqSEpkDOvRoEh03rPPtdriNWlksEcVoRi Yvhg== X-Gm-Message-State: AOAM533wMywJzggjI69ApA66RxJe+VurVvUFQZOlicCisCHf8s2ZYMqf I47KcOjAH8REWFPSRD1nmEw= X-Google-Smtp-Source: ABdhPJxcE7y5RNIqBzFldO7Er81oqzpsubv12PnOVaY8E5PITMD7Ye8STVzFVKLJWSPKkWdVt2wiNQ== X-Received: by 2002:a17:907:7b8b:: with SMTP id ne11mr13945663ejc.436.1643069081571; Mon, 24 Jan 2022 16:04:41 -0800 (PST) Received: from skbuf ([188.25.255.2]) by smtp.gmail.com with ESMTPSA id g8sm5511019ejt.26.2022.01.24.16.04.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 16:04:41 -0800 (PST) Date: Tue, 25 Jan 2022 02:04:39 +0200 From: Vladimir Oltean To: Tobias Waldekranz Cc: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Andrew Lunn , Vivien Didelot , Florian Fainelli , linux-kernel@vger.kernel.org Subject: Re: [PATCH net 2/2] net: dsa: Avoid cross-chip syncing of VLAN filtering Message-ID: <20220125000439.c4lbw3ivwunzzz23@skbuf> References: <20220124210944.3749235-1-tobias@waldekranz.com> <20220124210944.3749235-3-tobias@waldekranz.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220124210944.3749235-3-tobias@waldekranz.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 24, 2022 at 10:09:44PM +0100, Tobias Waldekranz wrote: > Changes to VLAN filtering are not applicable to cross-chip > notifications. Yes, it seems so. In a cross-chip setup, ports will individually leave the bridge, leaving every switch a chance to unset VLAN filtering. We have this check in dsa_port_vlan_filtering(), so it's easy to forget that the function is called more times than actually needed: if (dsa_port_is_vlan_filtering(dp) == vlan_filtering) return 0; Sorry. > On a system like this: > > .-----. .-----. .-----. > | sw1 +---+ sw2 +---+ sw3 | > '-1-2-' '-1-2-' '-1-2-' > > Before this change, upon sw1p1 leaving a bridge, a call to > dsa_port_vlan_filtering would also be made to sw2p1 and sw3p1. > > In this scenario: > > .---------. .-----. .-----. > | sw1 +---+ sw2 +---+ sw3 | > '-1-2-3-4-' '-1-2-' '-1-2-' > > When sw1p4 would leave a bridge, dsa_port_vlan_filtering would be > called for sw2 and sw3 with a non-existing port - leading to array > out-of-bounds accesses and crashes on mv88e6xxx. > > Fixes: d371b7c92d19 ("net: dsa: Unset vlan_filtering when ports leave the bridge") > Signed-off-by: Tobias Waldekranz > --- > net/dsa/switch.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/net/dsa/switch.c b/net/dsa/switch.c > index 9f9b70d6070a..517cc83d13cc 100644 > --- a/net/dsa/switch.c > +++ b/net/dsa/switch.c > @@ -180,9 +180,11 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds, > info->sw_index, info->port, > info->bridge); > > - err = dsa_switch_sync_vlan_filtering(ds, info); > - if (err) > - return err; > + if (ds->dst->index == info->tree_index && ds->index == info->sw_index) { > + err = dsa_switch_sync_vlan_filtering(ds, info); > + if (err) > + return err; > + } As net-next material, we could probably move this call to dsa_port_switchdev_unsync_attrs() where there's even a comment that references it, and do away with the targeted switch check. > > return dsa_tag_8021q_bridge_leave(ds, info); > } > -- > 2.25.1 > Reviewed-by: Vladimir Oltean