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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14CD4C54EED for ; Mon, 30 Jan 2023 14:21:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237455AbjA3OV0 (ORCPT ); Mon, 30 Jan 2023 09:21:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237683AbjA3OVK (ORCPT ); Mon, 30 Jan 2023 09:21:10 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 107253EC47 for ; Mon, 30 Jan 2023 06:20:01 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C8B00B80DEB for ; Mon, 30 Jan 2023 14:19:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10F86C433EF; Mon, 30 Jan 2023 14:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675088368; bh=egu2D/YqKHYG5NuhbpyZIlxw2lTZGiN2KyKeKrERyjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ir63C5scLYUQS/9XLwLHt8jQBp5pwFSQwdUik5JwXkgJH9lqRDhN9ZqlMbgbCCukn QcJ9ADLIR2ah0acGffMODqrDy6xhOngp35EFvJGjpAhvNOLPWcqmsldmDENp/IDuyb rMJ4b/u9THfPGB/qFP+9AgDUa766xtXneRl+GtRs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 170/204] netlink: prevent potential spectre v1 gadgets Date: Mon, 30 Jan 2023 14:52:15 +0100 Message-Id: <20230130134324.058625760@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230130134316.327556078@linuxfoundation.org> References: <20230130134316.327556078@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit f0950402e8c76e7dcb08563f1b4e8000fbc62455 ] Most netlink attributes are parsed and validated from __nla_validate_parse() or validate_nla() u16 type = nla_type(nla); if (type == 0 || type > maxtype) { /* error or continue */ } @type is then used as an array index and can be used as a Spectre v1 gadget. array_index_nospec() can be used to prevent leaking content of kernel memory to malicious users. This should take care of vast majority of netlink uses, but an audit is needed to take care of others where validation is not yet centralized in core netlink functions. Fixes: bfa83a9e03cf ("[NETLINK]: Type-safe netlink messages/attributes interface") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230119110150.2678537-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- lib/nlattr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/nlattr.c b/lib/nlattr.c index 86029ad5ead4..73635bdb0062 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -369,6 +370,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype, if (type <= 0 || type > maxtype) return 0; + type = array_index_nospec(type, maxtype + 1); pt = &policy[type]; BUG_ON(pt->type > NLA_TYPE_MAX); @@ -584,6 +586,7 @@ static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype, } continue; } + type = array_index_nospec(type, maxtype + 1); if (policy) { int err = validate_nla(nla, maxtype, policy, validate, extack, depth); -- 2.39.0