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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 7437AC3F2D1 for ; Tue, 3 Mar 2020 17:56:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E53620CC7 for ; Tue, 3 Mar 2020 17:56:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258195; bh=WqXLuGPjE0OeTW1ZYyh7Wc01TSayOhNRxj7vwyTBiOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uIczWMTw64u8s6H6TRt0mPVvxyAmpXWrFwNu9sOLWrXtHyTlv95/PUR55pZqbjE4s 8w3sVwtKLGwsFO1bq7adU3HBR/0lhik46HS0/0MKbDPygJOG0QcUg11iFV5xl7S/gG y64UtEozntCEVGvmCNuUq1uPI3ZncpfwsyLlRppQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731675AbgCCR4e (ORCPT ); Tue, 3 Mar 2020 12:56:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:38704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732913AbgCCR4a (ORCPT ); Tue, 3 Mar 2020 12:56:30 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7C3F7206D5; Tue, 3 Mar 2020 17:56:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258189; bh=WqXLuGPjE0OeTW1ZYyh7Wc01TSayOhNRxj7vwyTBiOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bsoiq2Y8ObKgGbnftHhkPMjKrEed4TjxmbAu4yl7YSzlhcYED3dJc33X0IyVgkp23 jLfHAYKXIG+tLFKg1e7ZVB/SKEK82fM1uF5LUDLNjCS4M/YH+wzSYhuk2hyenLRBJf k5z01vb3+B6tpQDzpOEmXFvnXVtLDqw8q9C4DHLY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Richard Guy Briggs , "Erhard F." , Nikolay Aleksandrov , "David S. Miller" Subject: [PATCH 5.4 106/152] net: netlink: cap max groups which will be considered in netlink_bind() Date: Tue, 3 Mar 2020 18:43:24 +0100 Message-Id: <20200303174314.675204257@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174302.523080016@linuxfoundation.org> References: <20200303174302.523080016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nikolay Aleksandrov commit 3a20773beeeeadec41477a5ba872175b778ff752 upstream. Since nl_groups is a u32 we can't bind more groups via ->bind (netlink_bind) call, but netlink has supported more groups via setsockopt() for a long time and thus nlk->ngroups could be over 32. Recently I added support for per-vlan notifications and increased the groups to 33 for NETLINK_ROUTE which exposed an old bug in the netlink_bind() code causing out-of-bounds access on archs where unsigned long is 32 bits via test_bit() on a local variable. Fix this by capping the maximum groups in netlink_bind() to BITS_PER_TYPE(u32), effectively capping them at 32 which is the minimum of allocated groups and the maximum groups which can be bound via netlink_bind(). CC: Christophe Leroy CC: Richard Guy Briggs Fixes: 4f520900522f ("netlink: have netlink per-protocol bind function return an error code.") Reported-by: Erhard F. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/netlink/af_netlink.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1014,7 +1014,8 @@ static int netlink_bind(struct socket *s if (nlk->netlink_bind && groups) { int group; - for (group = 0; group < nlk->ngroups; group++) { + /* nl_groups is a u32, so cap the maximum groups we can bind */ + for (group = 0; group < BITS_PER_TYPE(u32); group++) { if (!test_bit(group, &groups)) continue; err = nlk->netlink_bind(net, group + 1); @@ -1033,7 +1034,7 @@ static int netlink_bind(struct socket *s netlink_insert(sk, nladdr->nl_pid) : netlink_autobind(sock); if (err) { - netlink_undo_bind(nlk->ngroups, groups, sk); + netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk); goto unlock; } }