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Wed, 10 Jul 2019 00:17:01 -0700 (PDT) Date: Wed, 10 Jul 2019 00:15:07 -0700 In-Reply-To: <20190710071508.173491-1-brendanhiggins@google.com> Message-Id: <20190710071508.173491-18-brendanhiggins@google.com> Mime-Version: 1.0 References: <20190710071508.173491-1-brendanhiggins@google.com> X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH v8 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 X-Mailman-Original-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=9wLNCIVSUoQqeGTB89N+LVaQjLOY/UYArK2AxbIGTyA=; b=RGiz2ko9+VEL4DeuoDAOQU8iV8UJprPSVI78tm22MkvuA9zubiEzusp1PlBkj0SS+R 5s2oKCeuFrdi34plH9PuCQk1n9aimGsWL5FZECKizMtmnl96L3qWlO27oE/QMXtgLmzP qoSvrOtqZ5I8lB6vNPLanas/6MmKzEKWf1KIDMhMbS4zHP5qYFCL6ATGxGXGfJtrP+CG RbhI/t3w7Y+88H3pMp72adDt811FOeVhX2w6t7fyeoj6OHh6ArQEnKsKioLncI0Yb00t v0x18hrxtzNgbdxt5ZHx5ysvANmPMcpUIBLSMHP9IxLJKqmq6rzikBIWJ4Yya2134+pE 5VTg== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pmladek@suse.com, linux-doc@vger.kernel.org, amir73il@gmail.com, Brendan Higgins , dri-devel@lists.freedesktop.org, Alexander.Levin@microsoft.com, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, khilman@baylibre.com, knut.omang@oracle.com, wfg@linux.intel.com, joel@jms.id.au, rientjes@google.com, Iurii Zaikin , jdike@addtoit.com, dan.carpenter@oracle.com, devicetree@vger.kernel.org, linux-kbuild@vger.kernel.org, Tim.Bird@sony.com, linux-um@lists.infradead.org, rostedt@goodmis.org, julia.lawall@lip6.fr, kunit-dev@googlegroups.com, richard@nod.at, rdunlap@infradead.org, linux-kernel@vger.kernel.org, mpe@ellerman.id.au, linux-fsdevel@vger.kernel.org, logang@deltatee.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 --- kernel/Makefile | 2 + kernel/sysctl-test.c | 375 +++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 11 ++ 3 files changed, 388 insertions(+) create mode 100644 kernel/sysctl-test.c diff --git a/kernel/Makefile b/kernel/Makefile index a8d923b5481ba..50fd511cd0ee0 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -114,6 +114,8 @@ obj-$(CONFIG_HAS_IOMEM) += iomem.o obj-$(CONFIG_ZONE_DEVICE) += memremap.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..fc27b2c1185ca --- /dev/null +++ b/kernel/sysctl-test.c @@ -0,0 +1,375 @@ +// 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, + }; + void *buffer = 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 *buffer = 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 *buffer = 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 *buffer = 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, + }; + /* Put something in the buffer for debugging purposes. */ + char buf[] = "bogus"; + size_t len = sizeof(buf) - 1; + loff_t pos = 0; + /* Store 13 in the data field. */ + *((int *)table.data) = 13; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buf, + &len, &pos)); + KUNIT_ASSERT_EQ(test, (size_t)3, len); + buf[len] = '\0'; + /* And we read 13 back out. */ + KUNIT_EXPECT_STREQ(test, "13\n", (char *)buf); +} + +/* + * 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, + }; + char buf[] = "bogus"; + size_t len = sizeof(buf) - 1; + loff_t pos = 0; + *((int *)table.data) = -16; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buf, + &len, &pos)); + KUNIT_ASSERT_EQ(test, (size_t)4, len); + buf[len] = '\0'; + KUNIT_EXPECT_STREQ(test, "-16\n", (char *)buf); +} + +/* + * 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; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, input, + &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; + + KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, input, + &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, + }; + char input[32]; + size_t len = sizeof(input) - 1; + loff_t pos = 0; + 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(input, sizeof(input), "-%lu", + abs_of_less_than_min), + sizeof(input)); + + KUNIT_EXPECT_EQ(test, -EINVAL, + proc_dointvec(&table, KUNIT_PROC_WRITE, input, &len, + &pos)); + KUNIT_EXPECT_EQ(test, sizeof(input) - 1, 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, + }; + char input[32]; + size_t len = sizeof(input) - 1; + loff_t pos = 0; + 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(input, sizeof(input), "%lu", + greater_than_max), + sizeof(input)); + KUNIT_EXPECT_EQ(test, -EINVAL, + proc_dointvec(&table, KUNIT_PROC_WRITE, input, &len, + &pos)); + KUNIT_ASSERT_EQ(test, sizeof(input) - 1, 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 cbdfae3798965..6f8007800a76f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1939,6 +1939,17 @@ 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