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: 13024612 X-Patchwork-Delegate: palmer@dabbelt.com 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3E780ECAAA1 for ; Sat, 29 Oct 2022 11:44:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=APke/yHmwZQpIDRiTV9E8GLyPf3Og4FzW7UqM1pMpjM=; b=r9Pw9xcb2+qN5Q 0e5/DTio0CLsY5iiRmlQv5Y9xPzb+5Ih5cTCgglUvvwiBX2IpHW/4A32+3fX1IcUrBeqajTyOcEVc B+Ttv9eXzlCLvv7xXzaV1N/5/apI6XGTwHl/OCKAj9CfS9txTvDOCpwvIbFmxeuq+o+muOuoTA+Yk MqaWlY5RtA/Rsua4aBWGW4XY7SU9pU5MPug6OcXyA0ev3dG6OIgyAI0gyurQJ6dn2pnA0rimDt52a Rexo7lsdS6PremXS4zhHBTvfHXwN0BK8Qk7niaXctvWhksh4LLJA2afCgmGga9j2tZaiMxzscbJF7 lvpgs9LY4GhNMrXQnAJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ookGT-005zcy-A4; Sat, 29 Oct 2022 11:44:37 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ookGQ-005zcI-M4 for linux-riscv@lists.infradead.org; Sat, 29 Oct 2022 11:44:36 +0000 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 605C3B80B30; 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221029_044434_911959_9F6545F7 X-CRM114-Status: GOOD ( 10.34 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 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 */