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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD6C4C10F14 for ; Thu, 10 Oct 2019 10:45:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82DF220B7C for ; Thu, 10 Oct 2019 10:45:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732876AbfJJKpr (ORCPT ); Thu, 10 Oct 2019 06:45:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:37042 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726230AbfJJKpr (ORCPT ); Thu, 10 Oct 2019 06:45:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 84D03AFB1; Thu, 10 Oct 2019 10:45:45 +0000 (UTC) Received: by unicorn.suse.cz (Postfix, from userid 1000) id 32858E378C; Thu, 10 Oct 2019 12:45:45 +0200 (CEST) Date: Thu, 10 Oct 2019 12:45:45 +0200 From: Michal Kubecek To: netdev@vger.kernel.org Cc: Jiri Pirko , "David S. Miller" , Jiri Pirko , Johannes Berg , linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next] genetlink: do not parse attributes for families with zero maxattr Message-ID: <20191010104545.GB22163@unicorn.suse.cz> References: <20191009164432.AD5D1E3785@unicorn.suse.cz> <20191010093153.GG2223@nanopsycho> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191010093153.GG2223@nanopsycho> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 10, 2019 at 11:31:53AM +0200, Jiri Pirko wrote: > Wed, Oct 09, 2019 at 06:44:32PM CEST, mkubecek@suse.cz wrote: > >Commit c10e6cf85e7d ("net: genetlink: push attrbuf allocation and parsing > >to a separate function") moved attribute buffer allocation and attribute > >parsing from genl_family_rcv_msg_doit() into a separate function > >genl_family_rcv_msg_attrs_parse() which, unlike the previous code, calls > >__nlmsg_parse() even if family->maxattr is 0 (i.e. the family does its own > >parsing). The parser error is ignored and does not propagate out of > >genl_family_rcv_msg_attrs_parse() but an error message ("Unknown attribute > >type") is set in extack and if further processing generates no error or > >warning, it stays there and is interpreted as a warning by userspace. > > > >Dumpit requests are not affected as genl_family_rcv_msg_dumpit() bypasses > >the call of genl_family_rcv_msg_doit() if family->maxattr is zero. Do the > >same also in genl_family_rcv_msg_doit(). > > > >Fixes: c10e6cf85e7d ("net: genetlink: push attrbuf allocation and parsing to a separate function") > >Signed-off-by: Michal Kubecek > >--- > > net/netlink/genetlink.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > >diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c > >index ecc2bd3e73e4..c4bf8830eedf 100644 > >--- a/net/netlink/genetlink.c > >+++ b/net/netlink/genetlink.c > >@@ -639,21 +639,23 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family, > > const struct genl_ops *ops, > > int hdrlen, struct net *net) > > { > >- struct nlattr **attrbuf; > >+ struct nlattr **attrbuf = NULL; > > struct genl_info info; > > int err; > > > > if (!ops->doit) > > return -EOPNOTSUPP; > > > >+ if (!family->maxattr) > >+ goto no_attrs; > > attrbuf = genl_family_rcv_msg_attrs_parse(family, nlh, extack, > > ops, hdrlen, > > GENL_DONT_VALIDATE_STRICT, > >- family->maxattr && > > family->parallel_ops); > > Please also adjust genl_family_rcv_msg_attrs_free() call arg > below in this function in the similar way. Sent v2. Michal