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=-14.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,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 74284C43461 for ; Thu, 10 Sep 2020 09:35:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24B782075B for ; Thu, 10 Sep 2020 09:35:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="mdS2eI19"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="RdlZWBZ/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730808AbgIJJfv (ORCPT ); Thu, 10 Sep 2020 05:35:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730408AbgIJJWh (ORCPT ); Thu, 10 Sep 2020 05:22:37 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85782C06179F; Thu, 10 Sep 2020 02:22:17 -0700 (PDT) Date: Thu, 10 Sep 2020 09:22:12 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1599729733; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=odBe+hsn5smopQlsclW6Pk83LjFC5FJmfNaQ+36jlFw=; b=mdS2eI19MKEWlUOvf0E0K8RcVIqrG71kdMuFc7KCIb6yt878H14SZIcKK3Kyl7JSP208uB TDyfxVZQr52kVcfroKkHuuhbvXZlVf40qfbkF60KnyycpwICFV1zuo1fEe7D3T5xuCc6/8 GB8YrkxjcNAHj4XCEFIT0+YfxKNiFja8kTor1p0GO1aXFTnEzGVqUQUUrv3Sdtup7R/VuE Y8zVV6pqedmQ3pb7HplIrJBMHlhnBoSQJ4ANc+128UKr2tWz1g6aetIlk+WUeKlUs53Lti xBb6VX+5pb0h2raeAV0UWS0qKPk3e/nPiOWZ40ZYiXR4qZBlwTWxBqFTYMEsHA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1599729733; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=odBe+hsn5smopQlsclW6Pk83LjFC5FJmfNaQ+36jlFw=; b=RdlZWBZ/4NeQ/z9OaF6SqXvba4e3lb33IvUgU4DSDrNY+9FfgWHy929xn4ld8X6sHV/g9x b/VKQpXlzwgZ+yDg== From: "tip-bot2 for Joerg Roedel" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/seves] x86/sev-es: Handle instruction fetches from user-space Cc: Joerg Roedel , Borislav Petkov , x86 , LKML In-Reply-To: <20200907131613.12703-49-joro@8bytes.org> References: <20200907131613.12703-49-joro@8bytes.org> MIME-Version: 1.0 Message-ID: <159972973220.20229.16614295207021809730.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/seves branch of tip: Commit-ID: 5e3427a7bc432ed2e5de394ac30f160cc6c37a1f Gitweb: https://git.kernel.org/tip/5e3427a7bc432ed2e5de394ac30f160cc6c37a1f Author: Joerg Roedel AuthorDate: Mon, 07 Sep 2020 15:15:49 +02:00 Committer: Borislav Petkov CommitterDate: Wed, 09 Sep 2020 11:33:19 +02:00 x86/sev-es: Handle instruction fetches from user-space When a #VC exception is triggered by user-space, the instruction decoder needs to read the instruction bytes from user addresses. Enhance vc_decode_insn() to safely fetch kernel and user instructions. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200907131613.12703-49-joro@8bytes.org --- arch/x86/kernel/sev-es.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index b10a62a..6c30dbc 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -232,17 +232,30 @@ static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt) enum es_result ret; int res; - res = vc_fetch_insn_kernel(ctxt, buffer); - if (unlikely(res == -EFAULT)) { - ctxt->fi.vector = X86_TRAP_PF; - ctxt->fi.error_code = 0; - ctxt->fi.cr2 = ctxt->regs->ip; - return ES_EXCEPTION; + if (user_mode(ctxt->regs)) { + res = insn_fetch_from_user(ctxt->regs, buffer); + if (!res) { + ctxt->fi.vector = X86_TRAP_PF; + ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; + ctxt->fi.cr2 = ctxt->regs->ip; + return ES_EXCEPTION; + } + + if (!insn_decode(&ctxt->insn, ctxt->regs, buffer, res)) + return ES_DECODE_FAILED; + } else { + res = vc_fetch_insn_kernel(ctxt, buffer); + if (res) { + ctxt->fi.vector = X86_TRAP_PF; + ctxt->fi.error_code = X86_PF_INSTR; + ctxt->fi.cr2 = ctxt->regs->ip; + return ES_EXCEPTION; + } + + insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1); + insn_get_length(&ctxt->insn); } - insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1); - insn_get_length(&ctxt->insn); - ret = ctxt->insn.immediate.got ? ES_OK : ES_DECODE_FAILED; return ret;