From patchwork Tue Mar 10 17:45:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bernd Edlinger X-Patchwork-Id: 229430 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=-6.7 required=3.0 tests=FORGED_MUA_MOZILLA, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 67694C3F2C6 for ; Tue, 10 Mar 2020 17:45:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C16622525 for ; Tue, 10 Mar 2020 17:45:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726463AbgCJRpS (ORCPT ); Tue, 10 Mar 2020 13:45:18 -0400 Received: from mail-oln040092073033.outbound.protection.outlook.com ([40.92.73.33]:20294 "EHLO EUR04-HE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726414AbgCJRpS (ORCPT ); Tue, 10 Mar 2020 13:45:18 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=gQZVl/1n/5UYx0y4NOGyFbjmxgEBUJ6uczThMreoCeXfSJLiPK8FtnGvwIm/j7TiXD9yV959v87qydwyRvIupUyjcqys6r+NXM6FTAtcam5M2kvk7mB8YafFve1oGeKBZ+n86lAZ8tDNTcnQpjC0x8pGGOlriElTyjztCrWUIE1U42n3OuZ7LqxBvteQ5Vj0GSToZTiAjk6e7R/SiiTv4raf2GOFXlh7HUUIAskfja0XFvP/o4iKzn0HBgNVlXI6oYXoT9Ur1VhrnrOztmfGAO00NWyoz8kgA3Cf5hY0gmdWKB4AuJrh4flfEWFyrJuIldVzhT1OWRyfzQWPxynBJQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=KzW+vQiK0ldXBGN1Gu1zo93EbVuHDeiMyTvYP/RCPok=; b=ndfMms03pIShl9Jagnl2Y+jE9uQ50YPvwZ5z57agv/yPvDxTU/jbvXN6cekIkV9haRnHX6U2Z18HdjhTdcnWhT1lGcCeRYmeYN20TI+rvL/wrvEc9T61AX6R4a6j68rlB0lQvz9rrdUwYmzOpiInbIiwrnOgQj4O46FU9nQCnx1yyh9xSC5Dqs5zFfvs2q2/kqt5+mLdxrcoicInxMriC4NW4K5sp1bX9tHD2feGz+Y99P8gwEEOhw62CPapUwzf/2SClKn3n5UUevJLxff+TVEmTzJci25vGob9Q00hyON4cqQ0HXAXcY7tc95jaxBAcNWwL2Lopte220VOnMHRnA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=hotmail.de; dmarc=pass action=none header.from=hotmail.de; dkim=pass header.d=hotmail.de; arc=none Received: from VI1EUR04FT026.eop-eur04.prod.protection.outlook.com (2a01:111:e400:7e0e::39) by VI1EUR04HT138.eop-eur04.prod.protection.outlook.com (2a01:111:e400:7e0e::146) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11; Tue, 10 Mar 2020 17:45:14 +0000 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com (10.152.28.55) by VI1EUR04FT026.mail.protection.outlook.com (10.152.28.127) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11 via Frontend Transport; Tue, 10 Mar 2020 17:45:14 +0000 X-IncomingTopHeaderMarker: OriginalChecksum:B58AEAFA45C949DEBE05B6186D4DBF3A704E14AB315E4E49940646D624D8F720; UpperCasedChecksum:D4166CB02D7CDD15B20499B717F39622D99747916CD714472EDDFFCD7D29679A; SizeAsReceived:10317; Count:50 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd]) by AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd%6]) with mapi id 15.20.2793.013; Tue, 10 Mar 2020 17:45:14 +0000 From: Bernd Edlinger Subject: [PATCH 1/4] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve To: "Eric W. Biederman" Cc: Christian Brauner , Kees Cook , Jann Horn , Jonathan Corbet , Alexander Viro , Andrew Morton , Alexey Dobriyan , Thomas Gleixner , Oleg Nesterov , Frederic Weisbecker , Andrei Vagin , Ingo Molnar , "Peter Zijlstra (Intel)" , Yuyang Du , David Hildenbrand , Sebastian Andrzej Siewior , Anshuman Khandual , David Howells , James Morris , Greg Kroah-Hartman , Shakeel Butt , Jason Gunthorpe , Christian Kellner , Andrea Arcangeli , Aleksa Sarai , "Dmitry V. Levin" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "stable@vger.kernel.org" , "linux-api@vger.kernel.org" References: <87tv32cxmf.fsf_-_@x220.int.ebiederm.org> <87v9ne5y4y.fsf_-_@x220.int.ebiederm.org> <87zhcq4jdj.fsf_-_@x220.int.ebiederm.org> <878sk94eay.fsf@x220.int.ebiederm.org> <87r1y12yc7.fsf@x220.int.ebiederm.org> <87k13t2xpd.fsf@x220.int.ebiederm.org> <87d09l2x5n.fsf@x220.int.ebiederm.org> <871rq12vxu.fsf@x220.int.ebiederm.org> <877dzt1fnf.fsf@x220.int.ebiederm.org> <875zfcxlwy.fsf@x220.int.ebiederm.org> Message-ID: Date: Tue, 10 Mar 2020 18:45:11 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 In-Reply-To: <875zfcxlwy.fsf@x220.int.ebiederm.org> Content-Language: en-US X-ClientProxiedBy: ZR0P278CA0020.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:1c::7) To AM6PR03MB5170.eurprd03.prod.outlook.com (2603:10a6:20b:ca::23) X-Microsoft-Original-Message-ID: <030a2087-f995-327b-ac8f-3e2a0fda1c37@hotmail.de> MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.101] (92.77.140.102) by ZR0P278CA0020.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:1c::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.15 via Frontend Transport; Tue, 10 Mar 2020 17:45:12 +0000 X-Microsoft-Original-Message-ID: <030a2087-f995-327b-ac8f-3e2a0fda1c37@hotmail.de> X-TMN: [wZuXIGcgdH2Q8W6qKNBoXYGYM/eVthBC] X-MS-PublicTrafficType: Email X-IncomingHeaderCount: 50 X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-Correlation-Id: 99a48d4d-ff98-45a9-c82e-08d7c51ac9a5 X-MS-TrafficTypeDiagnostic: VI1EUR04HT138: X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: PdIIkda5kaGr6lCbIVe8507xJuc7fBfMn0QYZmW8k4t3Q3MbCWDJMMDiWdMmLtl2PFE/YUWOV1FNDYwyRFfzv2vwYeeLLX4U6AlNjdNlzH+bhhOshoQajl8XBjMVIFCeII80crHptCTpj0uLg6yiqXWHj5saLcQQbtl7rsNNXmUiYqStr3jojGpkIk1swnji X-MS-Exchange-AntiSpam-MessageData: HXLp8eDJv28UtDSkPAAw0rFQcA0ga+EyhrywohzN1kVn0SSi/oegskaWg6Gr4IT9WANm82RyL0ANRHysmEbj+7+qV1s92Cl2DdD5/lj9bCJT0x2UzbSqhrIgG6/7OfnS8+SnsUVr7GQJwQY2LY27eg== X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 99a48d4d-ff98-45a9-c82e-08d7c51ac9a5 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2020 17:45:14.2359 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-FromEntityHeader: Internet X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1EUR04HT138 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This changes kcmp_epoll_target to use the new exec_update_mutex instead of cred_guard_mutex. This should be safe, as the credentials are only used for reading, and furthermore ->mm and ->sighand are updated on execve, but only under the new exec_update_mutex. Signed-off-by: Bernd Edlinger --- kernel/kcmp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/kcmp.c b/kernel/kcmp.c index a0e3d7a..b3ff928 100644 --- a/kernel/kcmp.c +++ b/kernel/kcmp.c @@ -173,8 +173,8 @@ static int kcmp_epoll_target(struct task_struct *task1, /* * One should have enough rights to inspect task details. */ - ret = kcmp_lock(&task1->signal->cred_guard_mutex, - &task2->signal->cred_guard_mutex); + ret = kcmp_lock(&task1->signal->exec_update_mutex, + &task2->signal->exec_update_mutex); if (ret) goto err; if (!ptrace_may_access(task1, PTRACE_MODE_READ_REALCREDS) || @@ -229,8 +229,8 @@ static int kcmp_epoll_target(struct task_struct *task1, } err_unlock: - kcmp_unlock(&task1->signal->cred_guard_mutex, - &task2->signal->cred_guard_mutex); + kcmp_unlock(&task1->signal->exec_update_mutex, + &task2->signal->exec_update_mutex); err: put_task_struct(task1); put_task_struct(task2); From patchwork Tue Mar 10 13:44:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bernd Edlinger X-Patchwork-Id: 229435 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=-6.7 required=3.0 tests=FORGED_MUA_MOZILLA, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 F1387C1975A for ; Tue, 10 Mar 2020 13:44:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CABA524685 for ; Tue, 10 Mar 2020 13:44:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727921AbgCJNoN (ORCPT ); Tue, 10 Mar 2020 09:44:13 -0400 Received: from mail-oln040092064070.outbound.protection.outlook.com ([40.92.64.70]:44472 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726353AbgCJNoM (ORCPT ); Tue, 10 Mar 2020 09:44:12 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=DFhvp+Oo45MXHFV30ls6zqT7/546uqQptqKa+nZwGSFJbMbVs39WFCMR3R4+ZWtEAPmWz9sSFvBXcMZn0AT/yyLwW7fPZQV+dlBtynTVIP92g9Hxt3mC4Y7u2NXWrtqaQir7P0PO6wu+IfzH74keqMDowVxzqJzGSOSOpRA4Y/yvMjGVDbcIe0c/AV7POZGdy2re8ydZbI3rSxPq3OGoFEZpY8V32jOHuEcebdKL9+fn6muJ4RtebV5KSddLfS3ZYy7sGlR5cf/TgMsECc/ZUOX/9DVPFWSgsNP4byzCIhuIDwYFNrCk1fJ5RpqAF1VSV3aclDIfckMkv36j+4KKmw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qOZY463IAaXjiQVx7MRIl6eponpktQjQKIZPtfN8f0A=; b=cXWMpRR2CIXaZtvc0JBPdHMXIE7pdrMYY7W6C6JhFuzZdWpCjYoZepNahB2O+2VlSpx7pZ8TpRWAX05N85gT+L3sGVRt84yudbYdNT19apQzmZQHE+m2+vU1c4h71IFqhLRfscPzzvMwXdo3uXFUzNJ9HKE3rlGSHTYKnNs2zepozadCv+p3vXZ2r6CNhjqmwqgL5W2V/jrQyZmIUUfDqGyzUf6hePedfauhxZm6L9VUO569ZrrcRTc86IQnCh6na7FRhuWCEXoqN7FDcU5tXdGO0pb82xbZNwolU6vIRRo/4SBWAo5T+HgEzLtKz2Pw4pQKGZSZiQb11/Ybt1F1fQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=hotmail.de; dmarc=pass action=none header.from=hotmail.de; dkim=pass header.d=hotmail.de; arc=none Received: from HE1EUR01FT023.eop-EUR01.prod.protection.outlook.com (2a01:111:e400:7e18::37) by HE1EUR01HT005.eop-EUR01.prod.protection.outlook.com (2a01:111:e400:7e18::492) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11; Tue, 10 Mar 2020 13:44:03 +0000 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com (10.152.0.52) by HE1EUR01FT023.mail.protection.outlook.com (10.152.0.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11 via Frontend Transport; Tue, 10 Mar 2020 13:44:03 +0000 X-IncomingTopHeaderMarker: OriginalChecksum:2534592BB12048E38E56F803EF8B67E0599C52D4D49AF5C559ECF8080DBF5FF9; UpperCasedChecksum:01EBD96ECEB138968F5094E9AB20D61588959F6B6FFED1F4D775C0A1AC968775; SizeAsReceived:10294; Count:50 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd]) by AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd%6]) with mapi id 15.20.2793.013; Tue, 10 Mar 2020 13:44:03 +0000 From: Bernd Edlinger Subject: [PATCH 2/4] selftests/ptrace: add test cases for dead-locks To: "Eric W. Biederman" Cc: Christian Brauner , Kees Cook , Jann Horn , Jonathan Corbet , Alexander Viro , Andrew Morton , Alexey Dobriyan , Thomas Gleixner , Oleg Nesterov , Frederic Weisbecker , Andrei Vagin , Ingo Molnar , "Peter Zijlstra (Intel)" , Yuyang Du , David Hildenbrand , Sebastian Andrzej Siewior , Anshuman Khandual , David Howells , James Morris , Greg Kroah-Hartman , Shakeel Butt , Jason Gunthorpe , Christian Kellner , Andrea Arcangeli , Aleksa Sarai , "Dmitry V. Levin" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "stable@vger.kernel.org" , "linux-api@vger.kernel.org" References: <87r1y8dqqz.fsf@x220.int.ebiederm.org> <87tv32cxmf.fsf_-_@x220.int.ebiederm.org> <87v9ne5y4y.fsf_-_@x220.int.ebiederm.org> <87zhcq4jdj.fsf_-_@x220.int.ebiederm.org> <878sk94eay.fsf@x220.int.ebiederm.org> <87r1y12yc7.fsf@x220.int.ebiederm.org> <87k13t2xpd.fsf@x220.int.ebiederm.org> <87d09l2x5n.fsf@x220.int.ebiederm.org> <871rq12vxu.fsf@x220.int.ebiederm.org> <877dzt1fnf.fsf@x220.int.ebiederm.org> Message-ID: Date: Tue, 10 Mar 2020 14:44:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 In-Reply-To: <877dzt1fnf.fsf@x220.int.ebiederm.org> Content-Language: en-US X-ClientProxiedBy: AM0PR06CA0084.eurprd06.prod.outlook.com (2603:10a6:208:fa::25) To AM6PR03MB5170.eurprd03.prod.outlook.com (2603:10a6:20b:ca::23) X-Microsoft-Original-Message-ID: MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.101] (92.77.140.102) by AM0PR06CA0084.eurprd06.prod.outlook.com (2603:10a6:208:fa::25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.16 via Frontend Transport; Tue, 10 Mar 2020 13:44:01 +0000 X-Microsoft-Original-Message-ID: X-TMN: [mbH5VsuP3pnDx5S83zh5PLwQRoDsVQ4R] X-MS-PublicTrafficType: Email X-IncomingHeaderCount: 50 X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-Correlation-Id: f77651f4-c28d-44e1-771b-08d7c4f91823 X-MS-TrafficTypeDiagnostic: HE1EUR01HT005: X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: e3lk3mxrLBIqFPpGQyawO5+/E2DepRJw7nqU8+HOzUUV1tJZ5vXQ4OQxytSOH1PYS4u0VTkVrm3Ma/vPULqTzVD0oeY1W0nn/ROspV4OKXXw5aQI5BMO+LwqI3IQK7rlJjz9hgWJC0ShTt8eB+l4D4m3YnjZoNchxqx6NCl9ExDqRv035keCQeu5ZtRBYiEI X-MS-Exchange-AntiSpam-MessageData: UD3Fct7HirAC7qOQjBjLnzGmOlwPO0C65kL3A1S8q+1f/GsK7MYg9HzUCHCkqI7sA+dMLnxcfKeES/ctFXneRsd1eCglzjw2FOhCdSEakOwSEYWbIuQP8ojNt0stkZgqAozUAM0tip7VaTqslbmwYw== X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: f77651f4-c28d-44e1-771b-08d7c4f91823 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2020 13:44:03.1660 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-FromEntityHeader: Internet X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1EUR01HT005 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This adds test cases for ptrace deadlocks. Additionally fixes a compile problem in get_syscall_info.c, observed with gcc-4.8.4: get_syscall_info.c: In function 'get_syscall_info': get_syscall_info.c:93:3: error: 'for' loop initial declarations are only allowed in C99 mode for (unsigned int i = 0; i < ARRAY_SIZE(args); ++i) { ^ get_syscall_info.c:93:3: note: use option -std=c99 or -std=gnu99 to compile your code Signed-off-by: Bernd Edlinger --- tools/testing/selftests/ptrace/Makefile | 4 +- tools/testing/selftests/ptrace/vmaccess.c | 86 +++++++++++++++++++++++++++++++ 2 files changed, 88 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/ptrace/vmaccess.c diff --git a/tools/testing/selftests/ptrace/Makefile b/tools/testing/selftests/ptrace/Makefile index c0b7f89..2f1f532 100644 --- a/tools/testing/selftests/ptrace/Makefile +++ b/tools/testing/selftests/ptrace/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only -CFLAGS += -iquote../../../../include/uapi -Wall +CFLAGS += -std=c99 -pthread -iquote../../../../include/uapi -Wall -TEST_GEN_PROGS := get_syscall_info peeksiginfo +TEST_GEN_PROGS := get_syscall_info peeksiginfo vmaccess include ../lib.mk diff --git a/tools/testing/selftests/ptrace/vmaccess.c b/tools/testing/selftests/ptrace/vmaccess.c new file mode 100644 index 0000000..4db327b --- /dev/null +++ b/tools/testing/selftests/ptrace/vmaccess.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2020 Bernd Edlinger + * All rights reserved. + * + * Check whether /proc/$pid/mem can be accessed without causing deadlocks + * when de_thread is blocked with ->cred_guard_mutex held. + */ + +#include "../kselftest_harness.h" +#include +#include +#include +#include +#include +#include + +static void *thread(void *arg) +{ + ptrace(PTRACE_TRACEME, 0, 0L, 0L); + return NULL; +} + +TEST(vmaccess) +{ + int f, pid = fork(); + char mm[64]; + + if (!pid) { + pthread_t pt; + + pthread_create(&pt, NULL, thread, NULL); + pthread_join(pt, NULL); + execlp("true", "true", NULL); + } + + sleep(1); + sprintf(mm, "/proc/%d/mem", pid); + f = open(mm, O_RDONLY); + ASSERT_GE(f, 0); + close(f); + f = kill(pid, SIGCONT); + ASSERT_EQ(f, 0); +} + +TEST(attach) +{ + int s, k, pid = fork(); + + if (!pid) { + pthread_t pt; + + pthread_create(&pt, NULL, thread, NULL); + pthread_join(pt, NULL); + execlp("sleep", "sleep", "2", NULL); + } + + sleep(1); + k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); + ASSERT_EQ(errno, EAGAIN); + ASSERT_EQ(k, -1); + k = waitpid(-1, &s, WNOHANG); + ASSERT_NE(k, -1); + ASSERT_NE(k, 0); + ASSERT_NE(k, pid); + ASSERT_EQ(WIFEXITED(s), 1); + ASSERT_EQ(WEXITSTATUS(s), 0); + sleep(1); + k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); + ASSERT_EQ(k, 0); + k = waitpid(-1, &s, 0); + ASSERT_EQ(k, pid); + ASSERT_EQ(WIFSTOPPED(s), 1); + ASSERT_EQ(WSTOPSIG(s), SIGSTOP); + k = ptrace(PTRACE_DETACH, pid, 0L, 0L); + ASSERT_EQ(k, 0); + k = waitpid(-1, &s, 0); + ASSERT_EQ(k, pid); + ASSERT_EQ(WIFEXITED(s), 1); + ASSERT_EQ(WEXITSTATUS(s), 0); + k = waitpid(-1, NULL, 0); + ASSERT_EQ(k, -1); + ASSERT_EQ(errno, ECHILD); +} + +TEST_HARNESS_MAIN From patchwork Tue Mar 10 17:45:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bernd Edlinger X-Patchwork-Id: 229429 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=-6.7 required=3.0 tests=FORGED_MUA_MOZILLA, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 A6498C18E5A for ; 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Tue, 10 Mar 2020 17:45:50 +0000 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com (10.152.28.55) by VI1EUR04FT026.mail.protection.outlook.com (10.152.28.127) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11 via Frontend Transport; Tue, 10 Mar 2020 17:45:50 +0000 X-IncomingTopHeaderMarker: OriginalChecksum:4AE4C90853D8DDB61D15FD78AD842565F3BCC514A17005AD0DC52AEA26DFE82C; UpperCasedChecksum:93DC566E0BA2CB19E0B93FC62F35DC63F7A4E0955B4D558E5F3153D195CD6EA1; SizeAsReceived:10341; Count:50 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd]) by AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd%6]) with mapi id 15.20.2793.013; Tue, 10 Mar 2020 17:45:50 +0000 From: Bernd Edlinger Subject: [PATCH 3/4] proc: io_accounting: Use new infrastructure to fix deadlocks in execve To: "Eric W. Biederman" Cc: Christian Brauner , Kees Cook , Jann Horn , Jonathan Corbet , Alexander Viro , Andrew Morton , Alexey Dobriyan , Thomas Gleixner , Oleg Nesterov , Frederic Weisbecker , Andrei Vagin , Ingo Molnar , "Peter Zijlstra (Intel)" , Yuyang Du , David Hildenbrand , Sebastian Andrzej Siewior , Anshuman Khandual , David Howells , James Morris , Greg Kroah-Hartman , Shakeel Butt , Jason Gunthorpe , Christian Kellner , Andrea Arcangeli , Aleksa Sarai , "Dmitry V. Levin" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "stable@vger.kernel.org" , "linux-api@vger.kernel.org" References: <87tv32cxmf.fsf_-_@x220.int.ebiederm.org> <87v9ne5y4y.fsf_-_@x220.int.ebiederm.org> <87zhcq4jdj.fsf_-_@x220.int.ebiederm.org> <878sk94eay.fsf@x220.int.ebiederm.org> <87r1y12yc7.fsf@x220.int.ebiederm.org> <87k13t2xpd.fsf@x220.int.ebiederm.org> <87d09l2x5n.fsf@x220.int.ebiederm.org> <871rq12vxu.fsf@x220.int.ebiederm.org> <877dzt1fnf.fsf@x220.int.ebiederm.org> <875zfcxlwy.fsf@x220.int.ebiederm.org> Message-ID: Date: Tue, 10 Mar 2020 18:45:47 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 In-Reply-To: <875zfcxlwy.fsf@x220.int.ebiederm.org> Content-Language: en-US X-ClientProxiedBy: ZR0P278CA0028.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:1c::15) To AM6PR03MB5170.eurprd03.prod.outlook.com (2603:10a6:20b:ca::23) X-Microsoft-Original-Message-ID: <300abca9-375c-58ec-5cef-cbf1406a4464@hotmail.de> MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.101] (92.77.140.102) by ZR0P278CA0028.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:1c::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.14 via Frontend Transport; Tue, 10 Mar 2020 17:45:48 +0000 X-Microsoft-Original-Message-ID: <300abca9-375c-58ec-5cef-cbf1406a4464@hotmail.de> X-TMN: [XCvP3XhmcvfDfjTzxvAK99X2UOOLZOyp] X-MS-PublicTrafficType: Email X-IncomingHeaderCount: 50 X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-Correlation-Id: efb675c5-cbfb-4af6-12cd-08d7c51adf22 X-MS-TrafficTypeDiagnostic: VI1EUR04HT244: X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: /ZXrqPBjWbqOhkxrLTTusV/4/SaJoZmBMpE69amyQ2X7XgH6Wkmjuksf9e4l+mL34VfzmRAPiDoWPbzpD6lOt8nTC47JMpm2FnosaaJORYu7nakXyXB5rGhJM1723qUr5kPkPdFJDmfpqfa2UUSxIKbuU1B9NXAH8xAV2M1SY/1pmMGbKSL9KHI0Gsi1j3BY X-MS-Exchange-AntiSpam-MessageData: XUVtpUlamwAcWN3pgCDDxgnnyUIjSy/DoS3WNkkxjMEC5PMbEKiFoca7ABgSePO8N+zF7Lu4HcdIarJVa9FTb1sDw2iBVjG2Zc9sOu37RDb5Ha5tDA8wDlFpEpchBxs2uLif+MKQ/wZBjXIpF5/5Mg== X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: efb675c5-cbfb-4af6-12cd-08d7c51adf22 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2020 17:45:50.2526 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-FromEntityHeader: Internet X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1EUR04HT244 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This changes do_io_accounting to use the new exec_update_mutex instead of cred_guard_mutex. This fixes possible deadlocks when the trace is accessing /proc/$pid/io for instance. This should be safe, as the credentials are only used for reading. Signed-off-by: Bernd Edlinger --- fs/proc/base.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 4fdfe4f..529d0c6 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2770,7 +2770,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh unsigned long flags; int result; - result = mutex_lock_killable(&task->signal->cred_guard_mutex); + result = mutex_lock_killable(&task->signal->exec_update_mutex); if (result) return result; @@ -2806,7 +2806,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh result = 0; out_unlock: - mutex_unlock(&task->signal->cred_guard_mutex); + mutex_unlock(&task->signal->exec_update_mutex); return result; } From patchwork Tue Mar 10 13:44:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bernd Edlinger X-Patchwork-Id: 229434 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=-6.7 required=3.0 tests=FORGED_MUA_MOZILLA, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 7D48DC2BB8C for ; Tue, 10 Mar 2020 13:44:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53EBD20675 for ; Tue, 10 Mar 2020 13:44:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727960AbgCJNoa (ORCPT ); Tue, 10 Mar 2020 09:44:30 -0400 Received: from mail-oln040092065064.outbound.protection.outlook.com ([40.92.65.64]:21094 "EHLO EUR01-HE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726353AbgCJNoZ (ORCPT ); Tue, 10 Mar 2020 09:44:25 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=YsjjE4kKS6KrTu1V2AsyqPh6fKHbdgb28cEziFyjxyRs30uGyZjpEFz4hQg5utQt6Wf7Gjm4z3XW3SuKo2t+6zZksneiPJJCSW4zJgpdDhLr/Dq9l3rfnEiFu6frBJWKTAkGFgKbRcFps8lLKJqwKKjRNHUwjPG9pbhbt8tEfiarxwDz/P6TTYg/lwRepWPUldDo7S00Dabq/5247n2BDlIEBur4WXAfoKkYQjh9Qww+lD3jwNMXG/IEFY0KVqhSr+7iDNa6/hp/u5ZCxF5gcie5IC0/yKSNbf7S1EX8QfHBpggkmiNDy4E0hwIu+tMgOFukJU9G6ECIKqoR146XRg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=bLHW4bnkRE8FhDXjRsEkmXEsSRfI6uPgd9InYXaTyn4=; b=lxDJrM+xPKjfdADIHE6E+GE0b/6l+L/uPtSyXLyVWS3f0XJK/vC9yuNjcw7DaHFMF4GjUa6ci8Sa8mr5yUYUFjAI5PKhK1KFGjQ/0TdPnUX2FpK1+bHaNjo1/G6Y9pZxExGZcO+oCIBZe14D6x7mIxjyXG6VtEqLtJ7iymN2aatahD7gPPW7/n3yBmrS2LqIaVsSat8wQDiYI7CWSnDAm3Rgc6MIYYZpVZRWepQG9hY9tPGs9723VrFkVBu3L3jgvQJhq5iHJvXmCRsjUInTwKxgA9+HXgo7UFS/4Xu8sPvHVaANJpIsHCMKZnIhJzaT8ZtPGNpaBgValjRfOHKFSg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=hotmail.de; dmarc=pass action=none header.from=hotmail.de; dkim=pass header.d=hotmail.de; arc=none Received: from HE1EUR01FT023.eop-EUR01.prod.protection.outlook.com (2a01:111:e400:7e18::38) by HE1EUR01HT184.eop-EUR01.prod.protection.outlook.com (2a01:111:e400:7e18::426) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11; Tue, 10 Mar 2020 13:44:21 +0000 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com (10.152.0.52) by HE1EUR01FT023.mail.protection.outlook.com (10.152.0.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.11 via Frontend Transport; Tue, 10 Mar 2020 13:44:21 +0000 X-IncomingTopHeaderMarker: OriginalChecksum:7E750738653F338AC5481CC98ABEC498EE56D1454207C1D827F599A94EC87B9E; UpperCasedChecksum:546C79F509E24C24D31C77329F65014E73A7551D242F040C319041A4C5FA5FC8; SizeAsReceived:10300; Count:50 Received: from AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd]) by AM6PR03MB5170.eurprd03.prod.outlook.com ([fe80::1956:d274:cab3:b4dd%6]) with mapi id 15.20.2793.013; Tue, 10 Mar 2020 13:44:20 +0000 From: Bernd Edlinger Subject: [PATCH 4/4] kernel: doc: remove outdated comment cred.c To: "Eric W. Biederman" Cc: Christian Brauner , Kees Cook , Jann Horn , Jonathan Corbet , Alexander Viro , Andrew Morton , Alexey Dobriyan , Thomas Gleixner , Oleg Nesterov , Frederic Weisbecker , Andrei Vagin , Ingo Molnar , "Peter Zijlstra (Intel)" , Yuyang Du , David Hildenbrand , Sebastian Andrzej Siewior , Anshuman Khandual , David Howells , James Morris , Greg Kroah-Hartman , Shakeel Butt , Jason Gunthorpe , Christian Kellner , Andrea Arcangeli , Aleksa Sarai , "Dmitry V. Levin" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "stable@vger.kernel.org" , "linux-api@vger.kernel.org" References: <87r1y8dqqz.fsf@x220.int.ebiederm.org> <87tv32cxmf.fsf_-_@x220.int.ebiederm.org> <87v9ne5y4y.fsf_-_@x220.int.ebiederm.org> <87zhcq4jdj.fsf_-_@x220.int.ebiederm.org> <878sk94eay.fsf@x220.int.ebiederm.org> <87r1y12yc7.fsf@x220.int.ebiederm.org> <87k13t2xpd.fsf@x220.int.ebiederm.org> <87d09l2x5n.fsf@x220.int.ebiederm.org> <871rq12vxu.fsf@x220.int.ebiederm.org> <877dzt1fnf.fsf@x220.int.ebiederm.org> Message-ID: Date: Tue, 10 Mar 2020 14:44:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 In-Reply-To: <877dzt1fnf.fsf@x220.int.ebiederm.org> Content-Language: en-US X-ClientProxiedBy: AM0PR06CA0087.eurprd06.prod.outlook.com (2603:10a6:208:fa::28) To AM6PR03MB5170.eurprd03.prod.outlook.com (2603:10a6:20b:ca::23) X-Microsoft-Original-Message-ID: <26ec8f1e-607a-3464-e580-c68ae3cdbc70@hotmail.de> MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.101] (92.77.140.102) by AM0PR06CA0087.eurprd06.prod.outlook.com (2603:10a6:208:fa::28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2793.15 via Frontend Transport; Tue, 10 Mar 2020 13:44:19 +0000 X-Microsoft-Original-Message-ID: <26ec8f1e-607a-3464-e580-c68ae3cdbc70@hotmail.de> X-TMN: [fGR2VABPmKiLligx1HY68sPKWOnof6VG] X-MS-PublicTrafficType: Email X-IncomingHeaderCount: 50 X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-Correlation-Id: a9c155f3-bd6d-4879-c15e-08d7c4f922a1 X-MS-TrafficTypeDiagnostic: HE1EUR01HT184: X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 0Zh7x99FEz4cVfBEjGLhgYuzTuULKoVywh+n1v+3vpN8MSa68Yfye2zoJeUA3axCxAweLjyZYosWdyZIXte1s1QjvucfKtOYxpzJUUoqCR0W+Dz/4YpkyPU5G7mKFRXrUuV3yNvNmK3xg6h5SF7eyJ2rOeTfgH6jA6VQi8uAdS8rEAh/rqHKV59rkWRzdGPo X-MS-Exchange-AntiSpam-MessageData: ivLrgL/u02+FA2EPMhnF+65aFV1Qaky912d50Y5zLXtrJ+jE6gM09S8uzLts73rqNYJfcJ3RURUBl+wdBVZDwBdd3DFdie3i93MvOWgq+nVlQfJ6+7Di6e5Ns5Kprtk4GG2t7kREoSOzoSCc5YxSUw== X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: a9c155f3-bd6d-4879-c15e-08d7c4f922a1 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2020 13:44:20.5919 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-FromEntityHeader: Internet X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1EUR01HT184 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This removes an outdated comment in prepare_kernel_cred. There is no "cred_replace_mutex" any more, so the comment must go away. Signed-off-by: Bernd Edlinger --- kernel/cred.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/cred.c b/kernel/cred.c index 809a985..71a7926 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -675,8 +675,6 @@ void __init cred_init(void) * The caller may change these controls afterwards if desired. * * Returns the new credentials or NULL if out of memory. - * - * Does not take, and does not return holding current->cred_replace_mutex. */ struct cred *prepare_kernel_cred(struct task_struct *daemon) {