From patchwork Fri May 13 08:32:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 12848484 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 91543C433EF for ; Fri, 13 May 2022 08:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378292AbiEMIcd (ORCPT ); Fri, 13 May 2022 04:32:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241051AbiEMIcb (ORCPT ); Fri, 13 May 2022 04:32:31 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDD6564BC8 for ; Fri, 13 May 2022 01:32:27 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-2f7ee6bc6ddso66923457b3.1 for ; Fri, 13 May 2022 01:32:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=hUQluwx+IeHDQbtP0fjL9XDhdITsEoJIWpp8L9h5giw=; b=F/cDv7XyzfAhrhFHas6iEitptBabeLxs7JYySMnnIYCMoVWQlm1aMRtE+/SqhaEDNm CUtVY8Whw9qTUb+f6i/9SrNwUqK//hLviYObbOgELsaAp+e5PQTys3VZGSOL11haUR2h JXi3PzXSBFhTXTg6T1Af2lQ5jg98qlb1DqYvd/5im6SSwHSqg3+18b/zRgwbpeniHh5w dFaHx//RRMeVVvYwkpThQ2ynlPG4D3Z6TPN9+uRk3fk2kHCiIjA3uT5TTFvKie7Uwrfj xvGnEU8+v1psGFcZQC5sVKJwY5jyAB/aWooaKwolISkK6dLklWtYlS3y29i6SEb8U5+M i2xA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=hUQluwx+IeHDQbtP0fjL9XDhdITsEoJIWpp8L9h5giw=; b=7XzN0jwU2AHsF64b0bPoO79/jf7ZA3CWHrD7unD06u1O6mml9LLGf//JKWb1ddGfmQ tDfduiEK7lYAsznoWacijjpT5dfAhjJFMakflrivQXya2vg3fj0mWMwULwfCnIAbAR3F fqJH4B49MwZ5/8wAxiiJlo8/Ag8Ob3z8BNg8oBJJe3JxY//sDc9b/8+kQg1F/n1ail6k rwPeDnQWha4eo7jUJWsacgKYT9CRu9WFYu1IiCoqZz6l5v7zOMYAnosHiOK8ZxUheyK8 Y6ppiBKtrHbOZBbsY1iCKLo7GVR4Yo4bB6PMJ5ianBP9JyYkOOlK19U5vZFGcSWD+ePP QZew== X-Gm-Message-State: AOAM533sefDn/2Zz6KrF1qiJIYarhk6CETFWDZyc55mZw6khnXhhgcLi AVWF0TNwCK55QtBKoXoJNa7meqn+U+rgcw== X-Google-Smtp-Source: ABdhPJz63iUUnCr3zTam4iVPENkFDo9Hk9l7LA5hxnjO3aj6X2c1blool5DQ+WglykBzpsoKBGog87zoHV/MCQ== X-Received: from slicestar.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:20a1]) (user=davidgow job=sendgmr) by 2002:a0d:d689:0:b0:2fb:9a57:8517 with SMTP id y131-20020a0dd689000000b002fb9a578517mr4235720ywd.502.1652430747159; Fri, 13 May 2022 01:32:27 -0700 (PDT) Date: Fri, 13 May 2022 16:32:11 +0800 In-Reply-To: <20220429043913.626647-1-davidgow@google.com> Message-Id: <20220513083212.3537869-1-davidgow@google.com> Mime-Version: 1.0 References: <20220429043913.626647-1-davidgow@google.com> X-Mailer: git-send-email 2.36.0.550.gb090851708-goog Subject: [PATCH v3 1/3] panic: Taint kernel if tests are run From: David Gow To: Brendan Higgins , Andy Shevchenko , Jonathan Corbet , Andrew Morton , Kees Cook , Shuah Khan , Greg KH , Luis Chamberlain Cc: David Gow , "Guilherme G . Piccoli" , Sebastian Reichel , John Ogness , Joe Fradley , Daniel Latypov , kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Jani Nikula , Lucas De Marchi , Aaron Tomlin , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Most in-kernel tests (such as KUnit tests) are not supposed to run on production systems: they may do deliberately illegal things to trigger errors, and have security implications (for example, KUnit assertions will often deliberately leak kernel addresses). Add a new taint type, TAINT_TEST to signal that a test has been run. This will be printed as 'N' (originally for kuNit, as every other sensible letter was taken.) This should discourage people from running these tests on production systems, and to make it easier to tell if tests have been run accidentally (by loading the wrong configuration, etc.) Signed-off-by: David Gow Acked-by: Luis Chamberlain Reviewed-by: Brendan Higgins --- Updated this to handle the most common case of selftest modules, in addition to KUnit tests. There's room for other tests or test frameworks to use this as well, either with a call to add_taint() from within the kernel, or by writing to /proc/sys/kernel/tainted. The 'N' character for the taint is even less useful now that it's no longer short for kuNit, but all the letters in TEST are taken. :-( Changes since v2: https://lore.kernel.org/linux-kselftest/20220430030019.803481-1-davidgow@google.com/ - Rename TAINT_KUNIT -> TAINT_TEST. - Split into separate patches for adding the taint, and triggering it. - Taint on a kselftest_module being loaded (patch 3/3) Changes since v1: https://lore.kernel.org/linux-kselftest/20220429043913.626647-1-davidgow@google.com/ - Make the taint per-module, to handle the case when tests are in (longer lasting) modules. (Thanks Greg KH). Note that this still has checkpatch.pl warnings around bracket placement, which are intentional as part of matching the surrounding code. --- Documentation/admin-guide/tainted-kernels.rst | 1 + include/linux/panic.h | 3 ++- kernel/panic.c | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index ceeed7b0798d..546f3071940d 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -100,6 +100,7 @@ Bit Log Number Reason that got the kernel tainted 15 _/K 32768 kernel has been live patched 16 _/X 65536 auxiliary taint, defined for and used by distros 17 _/T 131072 kernel was built with the struct randomization plugin + 18 _/N 262144 an in-kernel test (such as a KUnit test) has been run === === ====== ======================================================== Note: The character ``_`` is representing a blank in this table to make reading diff --git a/include/linux/panic.h b/include/linux/panic.h index f5844908a089..2f5f2a9ecaf7 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -74,7 +74,8 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) #define TAINT_LIVEPATCH 15 #define TAINT_AUX 16 #define TAINT_RANDSTRUCT 17 -#define TAINT_FLAGS_COUNT 18 +#define TAINT_TEST 18 +#define TAINT_FLAGS_COUNT 19 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { diff --git a/kernel/panic.c b/kernel/panic.c index eb4dfb932c85..1cf707e3bacd 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -404,6 +404,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, [ TAINT_AUX ] = { 'X', ' ', true }, [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, + [ TAINT_TEST ] = { 'N', ' ', true }, }; /** From patchwork Fri May 13 08:32:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 12848486 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 644ECC433F5 for ; Fri, 13 May 2022 08:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378318AbiEMIcn (ORCPT ); Fri, 13 May 2022 04:32:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378266AbiEMIcf (ORCPT ); Fri, 13 May 2022 04:32:35 -0400 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5713A2A7C36 for ; Fri, 13 May 2022 01:32:32 -0700 (PDT) Received: by mail-pl1-x649.google.com with SMTP id x23-20020a170902b41700b0015ea144789fso4051787plr.13 for ; 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Fri, 13 May 2022 01:32:31 -0700 (PDT) Date: Fri, 13 May 2022 16:32:12 +0800 In-Reply-To: <20220429043913.626647-1-davidgow@google.com> Message-Id: <20220513083212.3537869-2-davidgow@google.com> Mime-Version: 1.0 References: <20220429043913.626647-1-davidgow@google.com> X-Mailer: git-send-email 2.36.0.550.gb090851708-goog Subject: [PATCH v3 2/3] kunit: Taint the kernel when KUnit tests are run From: David Gow To: Brendan Higgins , Andy Shevchenko , Jonathan Corbet , Andrew Morton , Kees Cook , Shuah Khan , Greg KH , Luis Chamberlain Cc: David Gow , "Guilherme G . Piccoli" , Sebastian Reichel , John Ogness , Joe Fradley , Daniel Latypov , kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Jani Nikula , Lucas De Marchi , Aaron Tomlin , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Make KUnit trigger the new TAINT_TEST taint when any KUnit test is run. Due to KUnit tests not being intended to run on production systems, and potentially causing problems (or security issues like leaking kernel addresses), the kernel's state should not be considered safe for production use after KUnit tests are run. Signed-off-by: David Gow Acked-by: Luis Chamberlain Tested-by: Daniel Latypov Reviewed-by: Brendan Higgins --- lib/kunit/test.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 0f66c13d126e..2b808117bd4a 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -498,6 +499,9 @@ int kunit_run_tests(struct kunit_suite *suite) struct kunit_result_stats suite_stats = { 0 }; struct kunit_result_stats total_stats = { 0 }; + /* Taint the kernel so we know we've run tests. */ + add_taint(TAINT_TEST, LOCKDEP_STILL_OK); + kunit_print_subtest_start(suite); kunit_suite_for_each_test_case(suite, test_case) { From patchwork Fri May 13 08:32:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 12848485 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 CD4A4C4332F for ; Fri, 13 May 2022 08:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378308AbiEMIcl (ORCPT ); Fri, 13 May 2022 04:32:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378318AbiEMIcj (ORCPT ); Fri, 13 May 2022 04:32:39 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED81B2A8074 for ; Fri, 13 May 2022 01:32:36 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id g26-20020a25b11a000000b0064984a4ffb7so6712573ybj.7 for ; Fri, 13 May 2022 01:32:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=hk5uEtV3LYTwsgSEedR4CtG2vms3qpu/B7wOj7VdRzM=; b=kYsNC7Eo1NPKL0cqSlEK8e68ZyQYRtrrD4EnKB7z+KZUKXD6WFKCXPMla4tDAyiQIg R1v92Ef6+EDCeojrvVKCFLPHuTXNldGmrN3nb9HL03DPkjJYrcMFg+FEzjRUKnv41p52 DaTPHxS5FuqN17a+jcm7VV3rkWuvNzYSRlAFDZ1WVlmZkoCNSAgwxJJ6kx1/K1dpk8UB oLOfeDKbeXB/4ENa6HPZYZL19N2I5sPvx4Acjap9xrQm9O0s0oit88YP4JxMHjYgoid+ UzSwLRjFMOKiGSVr/IAHMiXkp3ltx/Ft57LuU27hwohf3PH9UIVrKDk0ITX5r4ZD9gmV /XZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=hk5uEtV3LYTwsgSEedR4CtG2vms3qpu/B7wOj7VdRzM=; b=22i3dddhdXiKVAA+wQdEAgrjImNQey8Hsb+HG63/x3jEtNDDmJzlR7S5kDB4cjP4hJ ccKVj+/9Eju7KFFlUChBBgHOLoBh5Su9u4OSZmZMJhC3f2xjL0iG2NQeMyYT5QicV4Kn QBhJ6Y7WYGfMDQ5LjrRwO3U9igRKXZTyvauGTmbCWwaCOsbGoEXg9XxlhvFY0Jcz5Yk7 DTta8Bzb9VgSVztFYcwWIMXLaS33YX8N2jVgSb3z2N56GrcqAgR5UP/AIPAEdrBClg9Q rwLlRr03XcyWSQw0g3R1Aexj27+8J6K6d1cX7wYS5BsrKfypLKm/twzP1DS7q+Tm5Ae2 hA8Q== X-Gm-Message-State: AOAM530E8LdvmIAP/2M3HzYa1Vyx/kPTuGVt+4ExrVtychffcCB4TfhM AvdoMmmWd9s7b+acPajUHfY7Uk66lqkuwg== X-Google-Smtp-Source: ABdhPJw+htFPIH6EdUeS8xrLV26f4EOL11gNUDqQ9wJshw5TbY2Hsc8UJKgk0N0pjRBQIDiAvH1OrXDakVEOHQ== X-Received: from slicestar.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:20a1]) (user=davidgow job=sendgmr) by 2002:a25:4902:0:b0:648:d1db:af83 with SMTP id w2-20020a254902000000b00648d1dbaf83mr3678022yba.559.1652430756152; Fri, 13 May 2022 01:32:36 -0700 (PDT) Date: Fri, 13 May 2022 16:32:13 +0800 In-Reply-To: <20220429043913.626647-1-davidgow@google.com> Message-Id: <20220513083212.3537869-3-davidgow@google.com> Mime-Version: 1.0 References: <20220429043913.626647-1-davidgow@google.com> X-Mailer: git-send-email 2.36.0.550.gb090851708-goog Subject: [PATCH v3 3/3] selftest: Taint kernel when test module loaded From: David Gow To: Brendan Higgins , Andy Shevchenko , Jonathan Corbet , Andrew Morton , Kees Cook , Shuah Khan , Greg KH , Luis Chamberlain Cc: David Gow , "Guilherme G . Piccoli" , Sebastian Reichel , John Ogness , Joe Fradley , Daniel Latypov , kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Jani Nikula , Lucas De Marchi , Aaron Tomlin , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Make any kselftest test module (using the kselftest_module framework) taint the kernel with TAINT_TEST on module load. Note that several selftests use kernel modules which are not based on the kselftest_module framework, and so will not automatically taint the kernel. These modules will have to be manually modified if they should taint the kernel this way. Similarly, selftests which do not load modules into the kernel generally should not taint the kernel (or possibly should only do so on failure), as it's assumed that testing from user-space should be safe. Regardless, they can write to /proc/sys/kernel/tainted if required. Signed-off-by: David Gow --- tools/testing/selftests/kselftest_module.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/kselftest_module.h b/tools/testing/selftests/kselftest_module.h index e2ea41de3f35..226e616b82e0 100644 --- a/tools/testing/selftests/kselftest_module.h +++ b/tools/testing/selftests/kselftest_module.h @@ -3,6 +3,7 @@ #define __KSELFTEST_MODULE_H #include +#include /* * Test framework for writing test modules to be loaded by kselftest. @@ -41,6 +42,7 @@ static inline int kstm_report(unsigned int total_tests, unsigned int failed_test static int __init __module##_init(void) \ { \ pr_info("loaded.\n"); \ + add_taint(TAINT_KUNIT, LOCKDEP_STILL_OK); \ selftest(); \ return kstm_report(total_tests, failed_tests, skipped_tests); \ } \