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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 634EAC433F5 for ; Wed, 27 Oct 2021 14:17:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3358760232 for ; Wed, 27 Oct 2021 14:17:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242469AbhJ0OT1 (ORCPT ); Wed, 27 Oct 2021 10:19:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:40245 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242446AbhJ0ORU (ORCPT ); Wed, 27 Oct 2021 10:17:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635344094; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hJrML/RRrYOCcLcaDpLc5DyYFDVAJz2ir0815yDh2Js=; b=JaRW1soB9llkss5+C2fIC7esGFk1ATY6gC1dte8XyM/aZmz959zzDbTcsAIwBmsTvYkACY 110YpoGCeMUz1L7+UoCDguQWVsiHSdoypdKA7Jn9HQAhCAmZ8WVRWo9d0maNzvGrsUN7mG FmgOUJqjcF5S+LKmCe1UMs8F/+eD9RE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-504-AyFWpsHFNxWvgDJNk17mcw-1; Wed, 27 Oct 2021 10:14:51 -0400 X-MC-Unique: AyFWpsHFNxWvgDJNk17mcw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3DAFF1129581; Wed, 27 Oct 2021 14:14:49 +0000 (UTC) Received: from ceranb (unknown [10.40.193.230]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0781419D9F; Wed, 27 Oct 2021 14:14:46 +0000 (UTC) Date: Wed, 27 Oct 2021 16:14:40 +0200 From: Ivan Vecera To: Nikolay Aleksandrov Cc: netdev@vger.kernel.org, Roopa Prabhu , "David S. Miller" , Jakub Kicinski , Horatiu Vultur , Henrik Bjoernlund , "moderated list:ETHERNET BRIDGE" , open list Subject: Re: [PATCH net] net: bridge: fix uninitialized variables when BRIDGE_CFM is disabled Message-ID: <20211027161440.00cb1107@ceranb> In-Reply-To: References: <20211027134926.1412459-1-ivecera@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 Oct 2021 16:54:39 +0300 Nikolay Aleksandrov wrote: > On 27/10/2021 16:49, Ivan Vecera wrote: > > Function br_get_link_af_size_filtered() calls br_cfm_{,peer}_mep_count() > > but does not check their return value. When BRIDGE_CFM is not enabled > > these functions return -EOPNOTSUPP but do not modify count parameter. > > Calling function then works with uninitialized variables. > > > > Fixes: b6d0425b816e ("bridge: cfm: Netlink Notifications.") > > Signed-off-by: Ivan Vecera > > --- > > net/bridge/br_netlink.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c > > index 5c6c4305ed23..12d602495ea0 100644 > > --- a/net/bridge/br_netlink.c > > +++ b/net/bridge/br_netlink.c > > @@ -126,8 +126,10 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev, > > return vinfo_sz; > > > > /* CFM status info must be added */ > > - br_cfm_mep_count(br, &num_cfm_mep_infos); > > - br_cfm_peer_mep_count(br, &num_cfm_peer_mep_infos); > > + if (br_cfm_mep_count(br, &num_cfm_mep_infos) < 0) > > + num_cfm_mep_infos = 0; > > + if (br_cfm_peer_mep_count(br, &num_cfm_peer_mep_infos) < 0) > > + num_cfm_peer_mep_infos = 0; > > > > vinfo_sz += nla_total_size(0); /* IFLA_BRIDGE_CFM */ > > /* For each status struct the MEP instance (u32) is added */ > > > > Hi, > Could you please rather update the EOPNOTSUPP helpers to set these infos to 0 before > returning? Someone else might decide to use them and hit the same bug. > > E.g. > static inline int br_cfm_mep_count(struct net_bridge *br, u32 *count) > { > *count = 0; > return -EOPNOTSUPP; > } > > We already do the same for br_allowed_ingress, nbp_vlan_add() etc. > > Thanks, > Nik > Ok, Nik... works for me. Thanks, Ivan