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 6336DC433F5 for ; Mon, 3 Oct 2022 10:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229715AbiJCKjE (ORCPT ); Mon, 3 Oct 2022 06:39:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229698AbiJCKi5 (ORCPT ); Mon, 3 Oct 2022 06:38:57 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5341356EE for ; Mon, 3 Oct 2022 03:38:56 -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 71E33B81049 for ; Mon, 3 Oct 2022 10:38:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8D63C43141; Mon, 3 Oct 2022 10:38:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664793534; bh=C4Vx5tvsjc4GTe+ODm+teOUMFaKT91CBKzQiLXfj2dc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fMuZyrKBqrNiFoQFi+CtalwIR9BMcH8RYBA2q9Ikh+r1G+fCMFL0fy59iTweNgB+O 40MadJensyCmFJYgg2V7DGmIi0R1OdmX4SvpR2YrnHigZ5p/x1TVhl0pn+CELNambv RboGUr52C7Xp71TWbVhtIbce7ooMVP31jx57oF1CZ3wVbLPn/8c31Lr3B/r+ohOjcm e8PqHQdiRpXAoxF3W0j5fEzPto1ef7AYwcIPJ2FwXDFAdQR47430QWmq+cGEGMCS4L IGuA0A7K7BDRW6KpxrfV3WQQPVwyDNFfPOpmYbIPMS6wUuySlmfn8QRzR05K83j8WV 5M0QYkDgfjb0Q== 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 v3 1/4] riscv: process: fix kernel info leakage Date: Mon, 3 Oct 2022 18:29:18 +0800 Message-Id: <20221003102921.3973-2-jszhang@kernel.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221003102921.3973-1-jszhang@kernel.org> References: <20221003102921.3973-1-jszhang@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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 --- 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 */ -- 2.37.2