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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 378F5ECE58E for ; Fri, 11 Oct 2019 08:45:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19F952190F for ; Fri, 11 Oct 2019 08:45:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727364AbfJKIpr (ORCPT ); Fri, 11 Oct 2019 04:45:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:56238 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726508AbfJKIpr (ORCPT ); Fri, 11 Oct 2019 04:45:47 -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 9D9F1ABE3; Fri, 11 Oct 2019 08:45:45 +0000 (UTC) Received: by unicorn.suse.cz (Postfix, from userid 1000) id 91E73E378C; Fri, 11 Oct 2019 10:45:44 +0200 (CEST) From: Michal Kubecek Date: Fri, 11 Oct 2019 09:40:09 +0200 Subject: [PATCH net-next v3] genetlink: do not parse attributes for families with zero maxattr To: "David S. Miller" Cc: Jiri Pirko , Johannes Berg , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Message-Id: <20191011084544.91E73E378C@unicorn.suse.cz> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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_attrs_parse() if family->maxattr is zero. Move this logic inside genl_family_rcv_msg_attrs_parse() so that we don't have to handle it in each caller. v3: put the check inside genl_family_rcv_msg_attrs_parse() v2: adjust also argument of genl_family_rcv_msg_attrs_free() Fixes: c10e6cf85e7d ("net: genetlink: push attrbuf allocation and parsing to a separate function") Signed-off-by: Michal Kubecek --- net/netlink/genetlink.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index ecc2bd3e73e4..0522b2b1fd95 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -483,6 +483,9 @@ genl_family_rcv_msg_attrs_parse(const struct genl_family *family, struct nlattr **attrbuf; int err; + if (!family->maxattr) + return NULL; + if (parallel) { attrbuf = kmalloc_array(family->maxattr + 1, sizeof(struct nlattr *), GFP_KERNEL); @@ -582,9 +585,6 @@ static int genl_family_rcv_msg_dumpit(const struct genl_family *family, if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) return -EINVAL; - if (!family->maxattr) - goto no_attrs; - attrs = genl_family_rcv_msg_attrs_parse(family, nlh, extack, ops, hdrlen, GENL_DONT_VALIDATE_DUMP_STRICT, @@ -649,7 +649,6 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family, attrbuf = genl_family_rcv_msg_attrs_parse(family, nlh, extack, ops, hdrlen, GENL_DONT_VALIDATE_STRICT, - family->maxattr && family->parallel_ops); if (IS_ERR(attrbuf)) return PTR_ERR(attrbuf); @@ -676,8 +675,7 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family, family->post_doit(ops, skb, &info); out: - genl_family_rcv_msg_attrs_free(family, attrbuf, - family->maxattr && family->parallel_ops); + genl_family_rcv_msg_attrs_free(family, attrbuf, family->parallel_ops); return err; } -- 2.23.0