From patchwork Mon Aug 12 18:24:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Higgins X-Patchwork-Id: 11090561 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C0A31112C for ; Mon, 12 Aug 2019 18:25:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AF38328468 for ; Mon, 12 Aug 2019 18:25:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A32D028569; Mon, 12 Aug 2019 18:25:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9910728595 for ; Mon, 12 Aug 2019 18:25:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727199AbfHLSZ2 (ORCPT ); Mon, 12 Aug 2019 14:25:28 -0400 Received: from mail-pf1-f202.google.com ([209.85.210.202]:34161 "EHLO mail-pf1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727201AbfHLSZ2 (ORCPT ); Mon, 12 Aug 2019 14:25:28 -0400 Received: by mail-pf1-f202.google.com with SMTP id i2so66767051pfe.1 for ; Mon, 12 Aug 2019 11:25:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=CzAHSVcP6j1G3RzNCZt0Ao+T9N7OC/kha4hAVbnKvyc=; b=GqUC2YGIjKfWiuJzk5iSdgW6/w64xQW8WlQC5Bbrn/TYBB9QcV9+9DB4WsaEnRg3nb TO4x7DDRrutFVDYXliTgcLpAHpY1LB77H5sqDHQYBMvAUT5yZ5dURjlKN8XTyVpDNOCJ 493qsahYZPhVqadn4cye8qmaxjL94VFYO7RVV3sXAesUwDIWFdmVSu7rAIXmyjOi9abS hzz1MvrPDV6mpm5l4uqKW0ITNDR/UsyaXf2eUeUXJxrYKN/gwQAMDvCeuH4De+eXdUzi BaYhA5n6x2kQJi232XxRI3tOpGBYQhhGKZU0QtFBI35wzpzombrBV1qc4Powi8QUUAhF ol2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=CzAHSVcP6j1G3RzNCZt0Ao+T9N7OC/kha4hAVbnKvyc=; b=tfqx3U2MtDrl1WG5Rqt4tiq3sDxOddvaUut+mUlsA1nqvXQ4stPjZbLAuBam/rcDbj jRcb1P7A7/4harYg+Jr66XMyQ7gPxXrj8Ik5lUupr9EWn5tP/vhjjfEDwgakvhlR2CfY MDURQns6fJRClGSO3cIlZKM2lfLOawR/5dyTVuOEhNHPTIBtKTH0lGQ1ivmsXEPfuG7C jpgUjiNCJLMPO44Rpwpxi9r888NDFokEQ9DOHdkDea41WvyuBBqTsgrcXEkxycawKmo7 xD1bFYwaeFyDQUXuf3IXT0SVM+VO1diOre42NVwt98TH6oopThA3cGkqRCLI+BEwB1uf YnSw== X-Gm-Message-State: APjAAAVWGbEXrySA23oF/hGnRx/u0ciLKgmn8cAJgkx6ApkicWbyRkqU uuZ+Ku3+5/CBVyt5hM85P85KAgTyp+Ynxky7pOdasQ== X-Google-Smtp-Source: APXvYqwP/4jN2hQzABRKW8YdM+76JlZsRCLDT/L2pJh67/yt0IX/E02FpCfXO/pijfUuKU7gXeZnz+yIpudxeK9lyYExvw== X-Received: by 2002:a63:eb51:: with SMTP id b17mr30423034pgk.384.1565634326009; Mon, 12 Aug 2019 11:25:26 -0700 (PDT) Date: Mon, 12 Aug 2019 11:24:20 -0700 In-Reply-To: <20190812182421.141150-1-brendanhiggins@google.com> Message-Id: <20190812182421.141150-18-brendanhiggins@google.com> Mime-Version: 1.0 References: <20190812182421.141150-1-brendanhiggins@google.com> X-Mailer: git-send-email 2.23.0.rc1.153.gdeed80330f-goog Subject: [PATCH v12 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() From: Brendan Higgins To: frowand.list@gmail.com, gregkh@linuxfoundation.org, jpoimboe@redhat.com, keescook@google.com, kieran.bingham@ideasonboard.com, mcgrof@kernel.org, peterz@infradead.org, robh@kernel.org, sboyd@kernel.org, shuah@kernel.org, tytso@mit.edu, yamada.masahiro@socionext.com Cc: devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, kunit-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-um@lists.infradead.org, Alexander.Levin@microsoft.com, Tim.Bird@sony.com, amir73il@gmail.com, dan.carpenter@oracle.com, daniel@ffwll.ch, jdike@addtoit.com, joel@jms.id.au, julia.lawall@lip6.fr, khilman@baylibre.com, knut.omang@oracle.com, logang@deltatee.com, mpe@ellerman.id.au, pmladek@suse.com, rdunlap@infradead.org, richard@nod.at, rientjes@google.com, rostedt@goodmis.org, wfg@linux.intel.com, Iurii Zaikin , Brendan Higgins Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Iurii Zaikin KUnit tests for initialized data behavior of proc_dointvec that is explicitly checked in the code. Includes basic parsing tests including int min/max overflow. Signed-off-by: Iurii Zaikin Signed-off-by: Brendan Higgins Reviewed-by: Greg Kroah-Hartman Reviewed-by: Logan Gunthorpe Acked-by: Luis Chamberlain Reviewed-by: Stephen Boyd --- kernel/Makefile | 2 + kernel/sysctl-test.c | 392 +++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 11 ++ 3 files changed, 405 insertions(+) create mode 100644 kernel/sysctl-test.c diff --git a/kernel/Makefile b/kernel/Makefile index ef0d95a190b41..63e9ea6122c2c 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -113,6 +113,8 @@ obj-$(CONFIG_TORTURE_TEST) += torture.o obj-$(CONFIG_HAS_IOMEM) += iomem.o obj-$(CONFIG_RSEQ) += rseq.o +obj-$(CONFIG_SYSCTL_KUNIT_TEST) += sysctl-test.o + obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o KASAN_SANITIZE_stackleak.o := n KCOV_INSTRUMENT_stackleak.o := n diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c new file mode 100644 index 0000000000000..2a63241a8453b --- /dev/null +++ b/kernel/sysctl-test.c @@ -0,0 +1,392 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit test of proc sysctl. + */ + +#include +#include + +#define KUNIT_PROC_READ 0 +#define KUNIT_PROC_WRITE 1 + +static int i_zero; +static int i_one_hundred = 100; + +/* + * Test that proc_dointvec will not try to use a NULL .data field even when the + * length is non-zero. + */ +static void sysctl_test_api_dointvec_null_tbl_data(struct kunit *test) +{ + struct ctl_table null_data_table = { + .procname = "foo", + /* + * Here we are testing that proc_dointvec behaves correctly when + * we give it a NULL .data field. Normally this would point to a + * piece of memory where the value would be stored. + */ + .data = NULL, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + /* + * proc_dointvec expects a buffer in user space, so we allocate one. We + * also need to cast it to __user so sparse doesn't get mad. + */ + void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), + GFP_USER); + size_t len; + loff_t pos; + + /* + * We don't care what the starting length is since proc_dointvec should + * not try to read because .data is NULL. + */ + len = 1234; + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table, + KUNIT_PROC_READ, buffer, &len, + &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); + + /* + * See above. + */ + len = 1234; + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table, + KUNIT_PROC_WRITE, buffer, &len, + &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); +} + +/* + * Similar to the previous test, we create a struct ctrl_table that has a .data + * field that proc_dointvec cannot do anything with; however, this time it is + * because we tell proc_dointvec that the size is 0. + */ +static void sysctl_test_api_dointvec_table_maxlen_unset(struct kunit *test) +{ + int data = 0; + struct ctl_table data_maxlen_unset_table = { + .procname = "foo", + .data = &data, + /* + * So .data is no longer NULL, but we tell proc_dointvec its + * length is 0, so it still shouldn't try to use it. + */ + .maxlen = 0, + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), + GFP_USER); + size_t len; + loff_t pos; + + /* + * As before, we don't care what buffer length is because proc_dointvec + * cannot do anything because its internal .data buffer has zero length. + */ + len = 1234; + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table, + KUNIT_PROC_READ, buffer, &len, + &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); + + /* + * See previous comment. + */ + len = 1234; + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table, + KUNIT_PROC_WRITE, buffer, &len, + &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); +} + +/* + * Here we provide a valid struct ctl_table, but we try to read and write from + * it using a buffer of zero length, so it should still fail in a similar way as + * before. + */ +static void sysctl_test_api_dointvec_table_len_is_zero(struct kunit *test) +{ + int data = 0; + /* Good table. */ + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), + GFP_USER); + /* + * However, now our read/write buffer has zero length. + */ + size_t len = 0; + loff_t pos; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer, + &len, &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, buffer, + &len, &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); +} + +/* + * Test that proc_dointvec refuses to read when the file position is non-zero. + */ +static void sysctl_test_api_dointvec_table_read_but_position_set( + struct kunit *test) +{ + int data = 0; + /* Good table. */ + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int), + GFP_USER); + /* + * We don't care about our buffer length because we start off with a + * non-zero file position. + */ + size_t len = 1234; + /* + * proc_dointvec should refuse to read into the buffer since the file + * pos is non-zero. + */ + loff_t pos = 1; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer, + &len, &pos)); + KUNIT_EXPECT_EQ(test, (size_t)0, len); +} + +/* + * Test that we can read a two digit number in a sufficiently size buffer. + * Nothing fancy. + */ +static void sysctl_test_dointvec_read_happy_single_positive(struct kunit *test) +{ + int data = 0; + /* Good table. */ + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + size_t len = 4; + loff_t pos = 0; + char *buffer = kunit_kzalloc(test, len, GFP_USER); + char __user *user_buffer = (char __user *)buffer; + /* Store 13 in the data field. */ + *((int *)table.data) = 13; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, + user_buffer, &len, &pos)); + KUNIT_ASSERT_EQ(test, (size_t)3, len); + buffer[len] = '\0'; + /* And we read 13 back out. */ + KUNIT_EXPECT_STREQ(test, "13\n", buffer); +} + +/* + * Same as previous test, just now with negative numbers. + */ +static void sysctl_test_dointvec_read_happy_single_negative(struct kunit *test) +{ + int data = 0; + /* Good table. */ + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + size_t len = 5; + loff_t pos = 0; + char *buffer = kunit_kzalloc(test, len, GFP_USER); + char __user *user_buffer = (char __user *)buffer; + *((int *)table.data) = -16; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, + user_buffer, &len, &pos)); + KUNIT_ASSERT_EQ(test, (size_t)4, len); + buffer[len] = '\0'; + KUNIT_EXPECT_STREQ(test, "-16\n", (char *)buffer); +} + +/* + * Test that a simple positive write works. + */ +static void sysctl_test_dointvec_write_happy_single_positive(struct kunit *test) +{ + int data = 0; + /* Good table. */ + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + char input[] = "9"; + size_t len = sizeof(input) - 1; + loff_t pos = 0; + char *buffer = kunit_kzalloc(test, len, GFP_USER); + char __user *user_buffer = (char __user *)buffer; + + memcpy(buffer, input, len); + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, + user_buffer, &len, &pos)); + KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len); + KUNIT_EXPECT_EQ(test, sizeof(input) - 1, (size_t)pos); + KUNIT_EXPECT_EQ(test, 9, *((int *)table.data)); +} + +/* + * Same as previous test, but now with negative numbers. + */ +static void sysctl_test_dointvec_write_happy_single_negative(struct kunit *test) +{ + int data = 0; + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + char input[] = "-9"; + size_t len = sizeof(input) - 1; + loff_t pos = 0; + char *buffer = kunit_kzalloc(test, len, GFP_USER); + char __user *user_buffer = (char __user *)buffer; + + memcpy(buffer, input, len); + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, + user_buffer, &len, &pos)); + KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len); + KUNIT_EXPECT_EQ(test, sizeof(input) - 1, (size_t)pos); + KUNIT_EXPECT_EQ(test, -9, *((int *)table.data)); +} + +/* + * Test that writing a value smaller than the minimum possible value is not + * allowed. + */ +static void sysctl_test_api_dointvec_write_single_less_int_min( + struct kunit *test) +{ + int data = 0; + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + size_t max_len = 32, len = max_len; + loff_t pos = 0; + char *buffer = kunit_kzalloc(test, max_len, GFP_USER); + char __user *user_buffer = (char __user *)buffer; + unsigned long abs_of_less_than_min = (unsigned long)INT_MAX + - (INT_MAX + INT_MIN) + 1; + + /* + * We use this rigmarole to create a string that contains a value one + * less than the minimum accepted value. + */ + KUNIT_ASSERT_LT(test, + (size_t)snprintf(buffer, max_len, "-%lu", + abs_of_less_than_min), + max_len); + + KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE, + user_buffer, &len, &pos)); + KUNIT_EXPECT_EQ(test, max_len, len); + KUNIT_EXPECT_EQ(test, 0, *((int *)table.data)); +} + +/* + * Test that writing the maximum possible value works. + */ +static void sysctl_test_api_dointvec_write_single_greater_int_max( + struct kunit *test) +{ + int data = 0; + struct ctl_table table = { + .procname = "foo", + .data = &data, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }; + size_t max_len = 32, len = max_len; + loff_t pos = 0; + char *buffer = kunit_kzalloc(test, max_len, GFP_USER); + char __user *user_buffer = (char __user *)buffer; + unsigned long greater_than_max = (unsigned long)INT_MAX + 1; + + KUNIT_ASSERT_GT(test, greater_than_max, (unsigned long)INT_MAX); + KUNIT_ASSERT_LT(test, (size_t)snprintf(buffer, max_len, "%lu", + greater_than_max), + max_len); + KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE, + user_buffer, &len, &pos)); + KUNIT_ASSERT_EQ(test, max_len, len); + KUNIT_EXPECT_EQ(test, 0, *((int *)table.data)); +} + +static struct kunit_case sysctl_test_cases[] = { + KUNIT_CASE(sysctl_test_api_dointvec_null_tbl_data), + KUNIT_CASE(sysctl_test_api_dointvec_table_maxlen_unset), + KUNIT_CASE(sysctl_test_api_dointvec_table_len_is_zero), + KUNIT_CASE(sysctl_test_api_dointvec_table_read_but_position_set), + KUNIT_CASE(sysctl_test_dointvec_read_happy_single_positive), + KUNIT_CASE(sysctl_test_dointvec_read_happy_single_negative), + KUNIT_CASE(sysctl_test_dointvec_write_happy_single_positive), + KUNIT_CASE(sysctl_test_dointvec_write_happy_single_negative), + KUNIT_CASE(sysctl_test_api_dointvec_write_single_less_int_min), + KUNIT_CASE(sysctl_test_api_dointvec_write_single_greater_int_max), + {} +}; + +static struct kunit_suite sysctl_test_suite = { + .name = "sysctl_test", + .test_cases = sysctl_test_cases, +}; + +kunit_test_suite(sysctl_test_suite); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 5960e2980a8a0..a425741907b0d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1965,6 +1965,17 @@ config TEST_SYSCTL If unsure, say N. +config SYSCTL_KUNIT_TEST + bool "KUnit test for sysctl" + depends on KUNIT + help + This builds the proc sysctl unit test, which runs on boot. + Tests the API contract and implementation correctness of sysctl. + For more information on KUnit and unit tests in general please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. + config TEST_UDELAY tristate "udelay test driver" help