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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 0DED6C5CFC0 for ; Mon, 18 Jun 2018 08:48:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5C3A208D5 for ; Mon, 18 Jun 2018 08:48:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C5C3A208D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968063AbeFRIgg (ORCPT ); Mon, 18 Jun 2018 04:36:36 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36324 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967662AbeFRIgZ (ORCPT ); Mon, 18 Jun 2018 04:36:25 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 838B0CB7; Mon, 18 Jun 2018 08:36:24 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , Thomas Gleixner , Oleg Nesterov , Ricardo Neri , Francis Deslauriers , Alexei Starovoitov , Steven Rostedt , Andy Lutomirski , "H . Peter Anvin" , Yonghong Song , Borislav Petkov , Linus Torvalds , "David S . Miller" , Sasha Levin Subject: [PATCH 4.14 150/189] uprobes/x86: Prohibit probing on MOV SS instruction Date: Mon, 18 Jun 2018 10:14:06 +0200 Message-Id: <20180618081215.264329963@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180618081209.254234434@linuxfoundation.org> References: <20180618081209.254234434@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu [ Upstream commit 13ebe18c94f5b0665c01ae7fad2717ae959f4212 ] Since MOV SS and POP SS instructions will delay the exceptions until the next instruction is executed, single-stepping on it by uprobes must be prohibited. uprobe already rejects probing on POP SS (0x1f), but allows probing on MOV SS (0x8e and reg == 2). This checks the target instruction and if it is MOV SS or POP SS, returns -ENOTSUPP to reject probing. Signed-off-by: Masami Hiramatsu Signed-off-by: Thomas Gleixner Acked-by: Oleg Nesterov Cc: Ricardo Neri Cc: Francis Deslauriers Cc: Alexei Starovoitov Cc: Steven Rostedt Cc: Andy Lutomirski Cc: "H . Peter Anvin" Cc: Yonghong Song Cc: Borislav Petkov Cc: Linus Torvalds Cc: "David S . Miller" Link: https://lkml.kernel.org/r/152587072544.17316.5950935243917346341.stgit@devbox Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/uprobes.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -296,6 +296,10 @@ static int uprobe_init_insn(struct arch_ if (is_prefix_bad(insn)) return -ENOTSUPP; + /* We should not singlestep on the exception masking instructions */ + if (insn_masking_exception(insn)) + return -ENOTSUPP; + if (x86_64) good_insns = good_insns_64; else