From patchwork Wed Jun 7 07:29:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 104316 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp76611vqr; Wed, 7 Jun 2023 00:40:12 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5uop5kRscrpDBHpskw2IfhndqZaVnJ7pTJ2PHGZQr3wneDyVgRaGD7djUETYPUuI9M358q X-Received: by 2002:a05:6a00:2195:b0:639:a518:3842 with SMTP id h21-20020a056a00219500b00639a5183842mr5764306pfi.7.1686123612414; Wed, 07 Jun 2023 00:40:12 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1686123612; cv=none; d=google.com; s=arc-20160816; b=Cj+SwvHSiuIousnCHzWYxQ1pMZAzRBEmfMMDwkNVwpLD2Blpg62bxDQ3Fhjyusmabk kShBUTHdWeYZgax4XsDka1guwRXjMptEpnQbwI9CqbSWro8NkgjfhWAFE0Negj/0RDvD Yy6vtCUt7Bqo+ucsmiHNewzNoYtfrKv2dEYT2f8BIQgzX7z8t2IhmDPjOJXeCtHXROum 1tUGuF5IzgDM6cIYU1mdEdz0JATRcVC7iySmlRXDr/i42zXw4Fg2sW/6Qv3aeJyTdzuQ mAQM57Y9WEjTFIZ7G8CSdI79naaQecyZJCPekObf42vDU2BwNvqoBcPoE59kJxij3ONX hTHA== 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 :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=y8Pjt8EA8tFinVOCzCHnLFdQUw7jcSWs6svSbR9DVSQ=; b=KTUZt+n/fCTJ90AskZhAa22hyvXvF4T5MHC1sVhdWpqM2BegSGi2h0o3gmV71QYkHU UA9ytXQf6PSTs7/iBTNcEb8Y5ep5mHWx34XgM+jQ9WbisZ8l91l7zj2FfInTfMclZ0GG ohq6P/U/YGVExlfHpLun2FFswdI1R3GDtYIRfDfPst1bDrWeR0l3Tzz0ir98hXbPBHw4 OUQsslPl9zQ8/IIh7ezyqgos9xxgjUo52asGVjolCfAXxK8Kzq8DqN4nRTGJSsj+kLl5 trDVawoPYqiiuWcnqUaHoW5eqDLI/0DL6961ag6aQksBFQA7JYNp0ysk9MS+ChTnlN0K MNfw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@suse.com header.s=susede1 header.b=tNQhbwuz; 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=QUARANTINE sp=QUARANTINE dis=NONE) header.from=suse.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id r14-20020aa7988e000000b0066172edecccsi1228434pfl.145.2023.06.07.00.39.58; Wed, 07 Jun 2023 00:40:12 -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=@suse.com header.s=susede1 header.b=tNQhbwuz; 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=QUARANTINE sp=QUARANTINE dis=NONE) header.from=suse.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238879AbjFGHfy (ORCPT + 99 others); Wed, 7 Jun 2023 03:35:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239174AbjFGHeb (ORCPT ); Wed, 7 Jun 2023 03:34:31 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 144911BEF for ; Wed, 7 Jun 2023 00:29:44 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id B296B219EC; Wed, 7 Jun 2023 07:29:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1686122982; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=y8Pjt8EA8tFinVOCzCHnLFdQUw7jcSWs6svSbR9DVSQ=; b=tNQhbwuzxd5SYqDHVX1o1k0QPg1PyklcAk0KnWACq32tGICNwRNqxEcpfISX3DoiwspJma InYIIsN2JAZuvWOhF/lywInWaSzYm6Vlgg6fNqZxDHqt1tBGevmgEIzlefQ8vnHNXqlMvk RmV2oovEiZq5IZC61VRKr1+GcSKlyus= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 610D413776; Wed, 7 Jun 2023 07:29:42 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id OMwTFeYxgGSUIQAAMHmgww (envelope-from ); Wed, 07 Jun 2023 07:29:42 +0000 From: Nikolay Borisov To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, mhocko@suse.com, jslaby@suse.cz, Nikolay Borisov Subject: [PATCH 3/3] x86: Disable running 32bit processes if ia32_disabled is passed Date: Wed, 7 Jun 2023 10:29:36 +0300 Message-Id: <20230607072936.3766231-4-nik.borisov@suse.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230607072936.3766231-1-nik.borisov@suse.com> References: <20230607072936.3766231-1-nik.borisov@suse.com> MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED 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?1768028753236071642?= X-GMAIL-MSGID: =?utf-8?q?1768028753236071642?= In addition to disabling 32bit syscall interface let's also disable the ability to run 32bit processes altogether. This is achieved by setting the GDT_ENTRY_DEFAULT_USER32_CS descriptor to not present which would cause 32 bit processes to trap with a #NP exception. Furthermore, forbid loading compat processes as well. Signed-off-by: Nikolay Borisov --- arch/x86/include/asm/elf.h | 5 +++-- arch/x86/kernel/cpu/common.c | 8 ++++++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 18fd06f7936a..406245bc0fb0 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -148,9 +148,10 @@ do { \ #define elf_check_arch(x) \ ((x)->e_machine == EM_X86_64) +extern bool ia32_disabled; #define compat_elf_check_arch(x) \ - (elf_check_arch_ia32(x) || \ - (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64)) + (!ia32_disabled && (elf_check_arch_ia32(x) || \ + (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))) static inline void elf_common_init(struct thread_struct *t, struct pt_regs *regs, const u16 ds) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 71f8b55f70c9..ddc301c09419 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2359,6 +2359,11 @@ void microcode_check(struct cpuinfo_x86 *prev_info) } #endif +static void remove_user32cs_from_gdt(void * __unused) +{ + get_current_gdt_rw()[GDT_ENTRY_DEFAULT_USER32_CS].p = 0; +} + /* * Invoked from core CPU hotplug code after hotplug operations */ @@ -2368,4 +2373,7 @@ void arch_smt_update(void) cpu_bugs_smt_update(); /* Check whether IPI broadcasting can be enabled */ apic_smt_update(); + if (ia32_disabled) + on_each_cpu(remove_user32cs_from_gdt, NULL, 1); + }