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=-10.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 D3C89C43612 for ; Mon, 7 Jan 2019 12:46:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5DEB218A3 for ; Mon, 7 Jan 2019 12:46:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546865167; bh=14SzkCmzAl77VF5JB1afmF6wueko6+uUI9HX5sKNxAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bo3zaEAA+IcJe02FLP2x7OLuXHCrLVvrs9QIBGHEdKGvoETX9UBAHBsDNOQmh4eig gezc1hDuk1w+xGtYkxqz3Vxb90duJZOEt9l+4SIRJRlr503KGzhQvxnaWKY51mAfgI HHTa+H3BJ0lFoKMa2o4dLLSa6VCLm1bG7NuJ7Gdc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728994AbfAGMqG (ORCPT ); Mon, 7 Jan 2019 07:46:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:35812 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728978AbfAGMqD (ORCPT ); Mon, 7 Jan 2019 07:46:03 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 AEE162183E; Mon, 7 Jan 2019 12:46:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546865163; bh=14SzkCmzAl77VF5JB1afmF6wueko6+uUI9HX5sKNxAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mdrVHkVmToVm4CUCtA4tt7jXsAYScS02G8cRSXRXp1e2nhpTtQJq4dmi4h9ibJkbp AJ1Zgy+Vd5VAULyXh+HcJIeLbSjgAjz18P86F9f/l1BogxMgf9Y49+7YBABxrOzmMK KQ+AmloJq9BmCbD5mwiRr8tQ7pMu63iWddEVUijw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Gustavo A. R. Silva" , "David S. Miller" Subject: [PATCH 4.19 006/170] ipv4: Fix potential Spectre v1 vulnerability Date: Mon, 7 Jan 2019 13:30:33 +0100 Message-Id: <20190107104453.719883595@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190107104452.953560660@linuxfoundation.org> References: <20190107104452.953560660@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Gustavo A. R. Silva" [ Upstream commit 5648451e30a0d13d11796574919a359025d52cce ] vr.vifi is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: net/ipv4/ipmr.c:1616 ipmr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) net/ipv4/ipmr.c:1690 ipmr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) Fix this by sanitizing vr.vifi before using it to index mrt->vif_table' Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ipmr.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -69,6 +69,8 @@ #include #include +#include + struct ipmr_rule { struct fib_rule common; }; @@ -1612,6 +1614,7 @@ int ipmr_ioctl(struct sock *sk, int cmd, return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { @@ -1686,6 +1689,7 @@ int ipmr_compat_ioctl(struct sock *sk, u return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) {