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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 DD1BFC48BE5 for ; Mon, 21 Jun 2021 16:46:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA2216108E for ; Mon, 21 Jun 2021 16:46:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232790AbhFUQsN (ORCPT ); Mon, 21 Jun 2021 12:48:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:33896 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232850AbhFUQnd (ORCPT ); Mon, 21 Jun 2021 12:43:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 709CF6144F; Mon, 21 Jun 2021 16:31:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1624293103; bh=RzXCk9Dio8zmt6KXri5/MKKeCrYmJTpNj3bvQToYVFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mAHSqylNcWyEzJVpw+7oBNesJDcvxrKwFKr4LMEUpu51+BJd/kudQlyVJyvBCr55L croLYnu7of1ORiPv5fYbBTpHBwvU68BVmHnb5wAj/NE7MXud3x6QN7RIiJ120xZ4io +vXmFAu3Qy4u/QKHL4/eLtXDzwBimxL/+YuWXeFs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+59aa77b92d06cd5a54f2@syzkaller.appspotmail.com, Jakub Kicinski , "David S. Miller" , Sasha Levin Subject: [PATCH 5.12 056/178] ethtool: strset: fix message length calculation Date: Mon, 21 Jun 2021 18:14:30 +0200 Message-Id: <20210621154924.339857319@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210621154921.212599475@linuxfoundation.org> References: <20210621154921.212599475@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jakub Kicinski [ Upstream commit e175aef902697826d344ce3a12189329848fe898 ] Outer nest for ETHTOOL_A_STRSET_STRINGSETS is not accounted for. This may result in ETHTOOL_MSG_STRSET_GET producing a warning like: calculated message payload length (684) not sufficient WARNING: CPU: 0 PID: 30967 at net/ethtool/netlink.c:369 ethnl_default_doit+0x87a/0xa20 and a splat. As usually with such warnings three conditions must be met for the warning to trigger: - there must be no skb size rounding up (e.g. reply_size of 684); - string set must be per-device (so that the header gets populated); - the device name must be at least 12 characters long. all in all with current user space it looks like reading priv flags is the only place this could potentially happen. Or with syzbot :) Reported-by: syzbot+59aa77b92d06cd5a54f2@syzkaller.appspotmail.com Fixes: 71921690f974 ("ethtool: provide string sets with STRSET_GET request") Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ethtool/strset.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c index c3a5489964cd..9908b922cce8 100644 --- a/net/ethtool/strset.c +++ b/net/ethtool/strset.c @@ -328,6 +328,8 @@ static int strset_reply_size(const struct ethnl_req_info *req_base, int len = 0; int ret; + len += nla_total_size(0); /* ETHTOOL_A_STRSET_STRINGSETS */ + for (i = 0; i < ETH_SS_COUNT; i++) { const struct strset_info *set_info = &data->sets[i]; -- 2.30.2