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From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Daniel Micay <danielmicay@gmail.com>,
	Francis Laniel <laniel_francis@privacyrequired.com>,
	Bart Van Assche <bvanassche@acm.org>,
	David Gow <davidgow@google.com>,
	linux-mm@kvack.org, clang-built-linux@googlegroups.com,
	linux-hardening@vger.kernel.org
Subject: [PATCH for-next 21/25] lib: Introduce CONFIG_TEST_MEMCPY
Date: Sun, 22 Aug 2021 00:51:18 -0700	[thread overview]
Message-ID: <20210822075122.864511-22-keescook@chromium.org> (raw)
In-Reply-To: <20210822075122.864511-1-keescook@chromium.org>

Before changing anything about memcpy(), memmove(), and memset(), add
run-time tests to check basic behaviors for any regressions.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 MAINTAINERS       |   9 ++
 lib/Kconfig.debug |  11 ++
 lib/Makefile      |   1 +
 lib/test_memcpy.c | 265 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 286 insertions(+)
 create mode 100644 lib/test_memcpy.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 6c8be735cc91..e3ffd4bdc24f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7248,6 +7248,15 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/nvidia/*
 
+FORTIFY_SOURCE
+M:	Kees Cook <keescook@chomium.org>
+L:	linux-hardening@vger.kernel.org
+S:	Supported
+F:	include/linux/fortify-string.h
+F:	lib/test_fortify/*
+F:	scripts/test_fortify.sh
+K:	\b__NO_FORTIFY\b
+
 FPGA DFL DRIVERS
 M:	Wu Hao <hao.wu@intel.com>
 R:	Tom Rix <trix@redhat.com>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 831212722924..9199be57ba2a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2467,6 +2467,17 @@ config RATIONAL_KUNIT_TEST
 
 	  If unsure, say N.
 
+config MEMCPY_KUNIT_TEST
+	tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Builds unit tests for memcpy(), memmove(), and memset() functions.
+	  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
diff --git a/lib/Makefile b/lib/Makefile
index bd17c2bf43e1..8a4c8bdb38a2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
 obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
 obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o
+obj-$(CONFIG_TEST_MEMCPY) += test_memcpy.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_SORT) += test_sort.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
diff --git a/lib/test_memcpy.c b/lib/test_memcpy.c
new file mode 100644
index 000000000000..ec546cec883e
--- /dev/null
+++ b/lib/test_memcpy.c
@@ -0,0 +1,265 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for memcpy(), memmove(), and memset().
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+struct some_bytes {
+	union {
+		u8 data[32];
+		struct {
+			u32 one;
+			u16 two;
+			u8  three;
+			/* 1 byte hole */
+			u32 four[4];
+		};
+	};
+};
+
+#define check(instance, v) do {	\
+	int i;	\
+	BUILD_BUG_ON(sizeof(instance.data) != 32);	\
+	for (i = 0; i < sizeof(instance.data); i++) {	\
+		KUNIT_ASSERT_EQ_MSG(test, instance.data[i], v, \
+			"line %d: '%s' not initialized to 0x%02x @ %d (saw 0x%02x)\n", \
+			__LINE__, #instance, v, i, instance.data[i]);	\
+	}	\
+} while (0)
+
+#define compare(name, one, two) do { \
+	int i; \
+	BUILD_BUG_ON(sizeof(one) != sizeof(two)); \
+	for (i = 0; i < sizeof(one); i++) {	\
+		KUNIT_EXPECT_EQ_MSG(test, one.data[i], two.data[i], \
+			"line %d: %s.data[%d] (0x%02x) != %s.data[%d] (0x%02x)\n", \
+			__LINE__, #one, i, one.data[i], #two, i, two.data[i]); \
+	}	\
+	kunit_info(test, "ok: " TEST_OP "() " name "\n");	\
+} while (0)
+
+static void memcpy_test(struct kunit *test)
+{
+#define TEST_OP "memcpy"
+	struct some_bytes control = {
+		.data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			},
+	};
+	struct some_bytes zero = { };
+	struct some_bytes middle = {
+		.data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00,
+			  0x00, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			},
+	};
+	struct some_bytes three = {
+		.data = { 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+			},
+	};
+	struct some_bytes dest = { };
+	int count;
+	u8 *ptr;
+
+	/* Verify static initializers. */
+	check(control, 0x20);
+	check(zero, 0);
+	compare("static initializers", dest, zero);
+
+	/* Verify assignment. */
+	dest = control;
+	compare("direct assignment", dest, control);
+
+	/* Verify complete overwrite. */
+	memcpy(dest.data, zero.data, sizeof(dest.data));
+	compare("complete overwrite", dest, zero);
+
+	/* Verify middle overwrite. */
+	dest = control;
+	memcpy(dest.data + 12, zero.data, 7);
+	compare("middle overwrite", dest, middle);
+
+	/* Verify argument side-effects aren't repeated. */
+	dest = control;
+	ptr = dest.data;
+	count = 1;
+	memcpy(ptr++, zero.data, count++);
+	ptr += 8;
+	memcpy(ptr++, zero.data, count++);
+	compare("argument side-effects", dest, three);
+#undef TEST_OP
+}
+
+static void memmove_test(struct kunit *test)
+{
+#define TEST_OP "memmove"
+	struct some_bytes control = {
+		.data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes zero = { };
+	struct some_bytes middle = {
+		.data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00,
+			  0x00, 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes five = {
+		.data = { 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x00, 0x00, 0x00, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes overlap = {
+		.data = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+			  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes overlap_expected = {
+		.data = { 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x07,
+			  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
+			},
+	};
+	struct some_bytes dest = { };
+	int count;
+	u8 *ptr;
+
+	/* Verify static initializers. */
+	check(control, 0x99);
+	check(zero, 0);
+	compare("static initializers", zero, dest);
+
+	/* Verify assignment. */
+	dest = control;
+	compare("direct assignment", dest, control);
+
+	/* Verify complete overwrite. */
+	memmove(dest.data, zero.data, sizeof(dest.data));
+	compare("complete overwrite", dest, zero);
+
+	/* Verify middle overwrite. */
+	dest = control;
+	memmove(dest.data + 12, zero.data, 7);
+	compare("middle overwrite", dest, middle);
+
+	/* Verify argument side-effects aren't repeated. */
+	dest = control;
+	ptr = dest.data;
+	count = 2;
+	memmove(ptr++, zero.data, count++);
+	ptr += 9;
+	memmove(ptr++, zero.data, count++);
+	compare("argument side-effects", dest, five);
+
+	/* Verify overlapping overwrite is correct. */
+	ptr = &overlap.data[2];
+	memmove(ptr, overlap.data, 5);
+	compare("overlapping write", overlap, overlap_expected);
+#undef TEST_OP
+}
+
+static void memset_test(struct kunit *test)
+{
+#define TEST_OP "memset"
+	struct some_bytes control = {
+		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			},
+	};
+	struct some_bytes complete = {
+		.data = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			},
+	};
+	struct some_bytes middle = {
+		.data = { 0x30, 0x30, 0x30, 0x30, 0x31, 0x31, 0x31, 0x31,
+			  0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
+			  0x31, 0x31, 0x31, 0x31, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			},
+	};
+	struct some_bytes three = {
+		.data = { 0x60, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x61, 0x61, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+			},
+	};
+	struct some_bytes dest = { };
+	int count, value;
+	u8 *ptr;
+
+	/* Verify static initializers. */
+	check(control, 0x30);
+	check(dest, 0);
+
+	/* Verify assignment. */
+	dest = control;
+	compare("direct assignment", dest, control);
+
+	/* Verify complete overwrite. */
+	memset(dest.data, 0xff, sizeof(dest.data));
+	compare("complete overwrite", dest, complete);
+
+	/* Verify middle overwrite. */
+	dest = control;
+	memset(dest.data + 4, 0x31, 16);
+	compare("middle overwrite", dest, middle);
+
+	/* Verify argument side-effects aren't repeated. */
+	dest = control;
+	ptr = dest.data;
+	value = 0x60;
+	count = 1;
+	memset(ptr++, value++, count++);
+	ptr += 8;
+	memset(ptr++, value++, count++);
+	compare("argument side-effects", dest, three);
+#undef TEST_OP
+}
+
+static struct kunit_case memcpy_test_cases[] = {
+	KUNIT_CASE(memset_test),
+	KUNIT_CASE(memcpy_test),
+	KUNIT_CASE(memmove_test),
+	{}
+};
+
+static struct kunit_suite memcpy_test_suite = {
+	.name = "memcpy-test",
+	.test_cases = memcpy_test_cases,
+};
+
+kunit_test_suite(memcpy_test_suite);
+
+MODULE_LICENSE("GPL");
-- 
2.30.2


  parent reply	other threads:[~2021-08-22  7:57 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-22  7:50 [PATCH for-next 00/25] Prepare for better FORTIFY_SOURCE Kees Cook
2021-08-22  7:50 ` [PATCH for-next 01/25] scsi: ibmvscsi: Avoid multi-field memset() overflow by aiming at srp Kees Cook
2021-08-22  7:50 ` [PATCH for-next 02/25] powerpc: Split memset() to avoid multi-field overflow Kees Cook
2021-08-22  7:51 ` [PATCH for-next 03/25] stddef: Fix kerndoc for sizeof_field() and offsetofend() Kees Cook
2021-08-22  7:51 ` [PATCH for-next 04/25] stddef: Introduce struct_group() helper macro Kees Cook
2021-08-22  7:51 ` [PATCH for-next 05/25] cxl/core: Replace unions with struct_group() Kees Cook
2021-08-22  7:51 ` [PATCH for-next 06/25] bnxt_en: Use struct_group_attr() for memcpy() region Kees Cook
2021-08-22  7:51 ` [PATCH for-next 07/25] iommu/amd: Use struct_group() " Kees Cook
2021-08-22  7:51 ` [PATCH for-next 08/25] drm/mga/mga_ioc32: " Kees Cook
2021-08-22  7:51 ` [PATCH for-next 09/25] HID: cp2112: " Kees Cook
2021-08-22  7:51 ` [PATCH for-next 10/25] HID: roccat: Use struct_group() to zero kone_mouse_event Kees Cook
2021-08-22  7:51 ` [PATCH for-next 11/25] can: flexcan: Use struct_group() to zero struct flexcan_regs regions Kees Cook
2021-08-22  7:51 ` [PATCH for-next 12/25] cm4000_cs: Use struct_group() to zero struct cm4000_dev region Kees Cook
2021-08-22  7:51 ` [PATCH for-next 13/25] compiler_types.h: Remove __compiletime_object_size() Kees Cook
2021-08-23  6:43   ` Rasmus Villemoes
2021-08-25 19:43     ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 14/25] lib/string: Move helper functions out of string.c Kees Cook
2021-08-25 21:48   ` Nick Desaulniers
2021-08-26  2:47     ` Kees Cook
2021-08-26 18:08       ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 15/25] fortify: Move remaining fortify helpers into fortify-string.h Kees Cook
2021-08-25 21:59   ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 16/25] fortify: Explicitly disable Clang support Kees Cook
2021-08-25 19:41   ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 17/25] fortify: Fix dropped strcpy() compile-time write overflow check Kees Cook
2021-08-25 21:55   ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 18/25] fortify: Prepare to improve strnlen() and strlen() warnings Kees Cook
2021-08-25 22:01   ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 19/25] fortify: Allow strlen() and strnlen() to pass compile-time known lengths Kees Cook
2021-08-25 22:05   ` Nick Desaulniers
2021-08-26  2:56     ` Kees Cook
2021-08-26 18:02       ` Nick Desaulniers
2021-08-22  7:51 ` [PATCH for-next 20/25] fortify: Add compile-time FORTIFY_SOURCE tests Kees Cook
2021-08-22  7:51 ` Kees Cook [this message]
2021-08-24  7:00   ` [PATCH for-next 21/25] lib: Introduce CONFIG_TEST_MEMCPY David Gow
2021-08-25  2:32     ` Kees Cook
2021-10-18 15:46   ` Arnd Bergmann
2021-10-18 19:28     ` Kees Cook
2021-08-22  7:51 ` [PATCH for-next 22/25] string.h: Introduce memset_after() for wiping trailing members/padding Kees Cook
2021-08-22  7:51 ` [PATCH for-next 23/25] xfrm: Use memset_after() to clear padding Kees Cook
2021-08-22  7:51 ` [PATCH for-next 24/25] string.h: Introduce memset_startat() for wiping trailing members and padding Kees Cook
2021-08-22  7:51 ` [PATCH for-next 25/25] btrfs: Use memset_startat() to clear end of struct Kees Cook

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