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 10636C3F2D1 for ; Tue, 3 Mar 2020 18:03:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF57B20836 for ; Tue, 3 Mar 2020 18:03:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258621; bh=4HlcNQ/u8dWefz42EWicmru3mNA3W0RTIiIe9h0A0Kk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mlg6zHwjaerhB7xsNr/KNDoWs9uQUW1xfarvd/beuxzGH3344Ad28oi74K+8QFYS8 aTs0AQc8+Z61M7uQOne7TJlGPJs4B3Ektu45BMMkVw0Lc/fQMxeJs+CmbkZLZSaEgd A1ZC0Yxhq4uBQRivpF7WIMOzXttzvpV7gwGXP6cg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387924AbgCCSBS (ORCPT ); Tue, 3 Mar 2020 13:01:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:45344 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387935AbgCCSBQ (ORCPT ); Tue, 3 Mar 2020 13:01:16 -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 5BABF20866; Tue, 3 Mar 2020 18:01:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258475; bh=4HlcNQ/u8dWefz42EWicmru3mNA3W0RTIiIe9h0A0Kk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nPlhYatJ6Twl+9446//8K8RP+euM2SE7v+FpfkYjaAJx7xJp7VisaRRJjbata6yZd PXD1SW5uREDMwum1rrWKVq0yPcmjCMbtekg/T0DjSFs4oU+x6D0TnyNikTq+WG98Gn iolVcMZxTicyfEq4OyMHPq9H2tVFs80KKFm4788s= 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 4.19 62/87] net: netlink: cap max groups which will be considered in netlink_bind() Date: Tue, 3 Mar 2020 18:43:53 +0100 Message-Id: <20200303174355.918762979@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174349.075101355@linuxfoundation.org> References: <20200303174349.075101355@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -1029,7 +1029,8 @@ 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); @@ -1048,7 +1049,7 @@ 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; } }