From patchwork Sat Oct 29 11:34:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 12689 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp1309049wru; Sat, 29 Oct 2022 04:52:40 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5xWjXncfJCr6YyW3nNwy+d4YiydTaAK2DYgxcY7xEcMA7rZbsLNTNjGkl11u9tqkuaJbi/ X-Received: by 2002:a62:1e81:0:b0:563:8689:d295 with SMTP id e123-20020a621e81000000b005638689d295mr4155216pfe.6.1667044359937; Sat, 29 Oct 2022 04:52:39 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667044359; cv=none; d=google.com; s=arc-20160816; b=dKVGwug+nT9b6eqztyoQjsMIeapOwiRROKzZXQLi9KCXpuwjUrDrxB7wFo6KbzSDgb 9BfMF/27Op7CNPsmpBrDpxiu+3am95B1yGZkCeHVpP/Q89s9GCtoCV3Ws0AIoKxHUmiQ w1KXZhYJSB70lSMJRWzCQNR1KQvCVw9C7ziWd1xfJhV+P8bDbrwBpjfUloE5S5L52fcc n6xlTh3d5RA81HpwyIDnhNqMnfNLtbECdT58EUb2E2yuq79jfOY/aHd7SSq7x3y2I7YS i16rM4Xly/58oVId7U9b7BvB4rRgGgP6n2stv28I2id8pud+3l2lmrpx07SNQOjsuazJ uqwQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=yE8ce/R92CCoEujuXQ/3LVrlytcgzdtb1gwjjAnrsck=; b=I4lpe6XuJUWY20u7ccjZJq3fpKtEV6LdddIyqc2CigbThVzlIL4v0NR4klPMKk6OUR p8X8A2iCr294czvnSQVuNj8CLWgYln1e5rKKp76ipkDBOjMeP1OpspdaPlekR/2/ITWf FqeUprjJDQcKH/aWUaw5d9jrmHDSviidfqSTz0Dk3FKuJMV1b7M01wUDquAPO9Q7w97L HmLTX1EaR1X5Vvz9iIxliylPGsKxmuUXG/rqobGg/hhR/sE2UEiN61H5al3vqWNxK4Jy wMgBoHDhGQH+Dos1M57cR8OkpaG5ILe56+gD31GMOiEFX/vXgiX1EiuCVF3Lo3DqTtT3 zpyw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=lJQCVzoS; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id l71-20020a63914a000000b0046ece301e82si1694012pge.756.2022.10.29.04.52.27; Sat, 29 Oct 2022 04:52:39 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=lJQCVzoS; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229636AbiJ2Loq (ORCPT + 99 others); Sat, 29 Oct 2022 07:44:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229542AbiJ2Lop (ORCPT ); Sat, 29 Oct 2022 07:44:45 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7DE3140A4 for ; Sat, 29 Oct 2022 04:44:33 -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 697CDB80B89 for ; Sat, 29 Oct 2022 11:44:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 964CFC433C1; Sat, 29 Oct 2022 11:44:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667043871; bh=J28JdYpCrFXzwuwKWXs/vDRdRU6kc34gc/wpq/7Yrq8=; h=From:To:Cc:Subject:Date:From; b=lJQCVzoSRltfxdwtmLMUMk60jyAIBldT+rATXalj1lD5A5fdYS8ez64sIMxWGpJdX 5HV08QwiLSVQVzjLC55XS3hzSrmfzWOIhpoYVQxeyPHn1ZDllNA7f6oP3hF8AGzmuy CCAmBvlilfgvUeUZsPYNb1Yk/RqYWqRLcDSV4Cj5n2DU6VIzZp05LYmO2Gw/m+6GPk W5vqpciI8BDDspbmGhZDRmjrlqd6ELaWZcV8t6t6z1E7HG6C07tmfmfYAwhLK6GgUH mZlOX30ktd2RmODr8Px4kWDSGXuO8G8O8yol2yAg1ZOyYtJhWFAlskOIL5I2qzCCSK ISn6ycpXNsiaQ== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] riscv: process: fix kernel info leakage Date: Sat, 29 Oct 2022 19:34:50 +0800 Message-Id: <20221029113450.4027-1-jszhang@kernel.org> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748022706998477915?= X-GMAIL-MSGID: =?utf-8?q?1748022706998477915?= thread_struct's s[12] may contain random kernel memory content, which may be finally leaked to userspace. This is a security hole. Fix it by clearing the s[12] array in thread_struct when fork. As for kthread case, it's better to clear the s[12] array as well. Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Signed-off-by: Jisheng Zhang Tested-by: Guo Ren --- Previously, it's one of the series of "riscv: entry: further clean up and VMAP_STACK fix". This is a fix, so I move it out of the series and send it separately arch/riscv/kernel/process.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index ceb9ebab6558..52002d54b163 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -164,6 +164,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); + memset(&p->thread.s, 0, sizeof(p->thread.s)); + /* p->thread holds context to be restored by __switch_to() */ if (unlikely(args->fn)) { /* Kernel thread */