From patchwork Tue Apr 12 06:28:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 560659 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 94426C4332F for ; Tue, 12 Apr 2022 06:57:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240641AbiDLG7l (ORCPT ); Tue, 12 Apr 2022 02:59:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352598AbiDLG4E (ORCPT ); Tue, 12 Apr 2022 02:56:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14ACB245B7; Mon, 11 Apr 2022 23:46:10 -0700 (PDT) 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 B701EB818C8; Tue, 12 Apr 2022 06:46:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AE08C385A1; Tue, 12 Apr 2022 06:46:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649745967; bh=OQWOmuqUFSTpEgakia4l7pulw8EHANnP/KZzLKSdX4o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MN+q5ymzItEogKFnzObJ/9Rr8du/GIE13UbKoTgtzFbkrTDp7598ZCuGIQdmM0VQZ E98MqZYp2xOlMUqPGvBgNySGTX9PJIBCLYbefuK2hoafRHAQ3Q1o6isXYWn/fLxr+H Z0Gt7WzKQpppscUUl/jsqu6EOF4uO/EdCgjVmJb0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, George Shuklin , David Ahern , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 095/277] net: limit altnames to 64k total Date: Tue, 12 Apr 2022 08:28:18 +0200 Message-Id: <20220412062944.792494036@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062942.022903016@linuxfoundation.org> References: <20220412062942.022903016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jakub Kicinski [ Upstream commit 155fb43b70b5fce341347a77d1af2765d1e8fbb8 ] Property list (altname is a link "property") is wrapped in a nlattr. nlattrs length is 16bit so practically speaking the list of properties can't be longer than that, otherwise user space would have to interpret broken netlink messages. Prevent the problem from occurring by checking the length of the property list before adding new entries. Reported-by: George Shuklin Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/rtnetlink.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index a8c319dc224a..9c0e8ccf9bc5 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3631,12 +3631,23 @@ static int rtnl_alt_ifname(int cmd, struct net_device *dev, struct nlattr *attr, bool *changed, struct netlink_ext_ack *extack) { char *alt_ifname; + size_t size; int err; err = nla_validate(attr, attr->nla_len, IFLA_MAX, ifla_policy, extack); if (err) return err; + if (cmd == RTM_NEWLINKPROP) { + size = rtnl_prop_list_size(dev); + size += nla_total_size(ALTIFNAMSIZ); + if (size >= U16_MAX) { + NL_SET_ERR_MSG(extack, + "effective property list too long"); + return -EINVAL; + } + } + alt_ifname = nla_strdup(attr, GFP_KERNEL_ACCOUNT); if (!alt_ifname) return -ENOMEM;