[PATCH linux-kselftest/test v1] apparmor: add AppArmor KUnit tests for policy unpack

[Brendan Higgins <brendanhiggins@google.com>]

From: Mike Salvatore <mike.salvatore@canonical.com>

Add KUnit tests to test AppArmor unpacking of userspace policies.
AppArmor uses a serialized binary format for loading policies. To find
policy format documentation see
Documentation/admin-guide/LSM/apparmor.rst.

In order to write the tests against the policy unpacking code, some
static functions needed to be exposed for testing purposes. One of the
goals of this patch is to establish a pattern for which testing these
kinds of functions should be done in the future.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Mike Salvatore <mike.salvatore@canonical.com>
---
Sorry in advanced for emailing so many people. I suspect that there are
quite a few people who will be interested in this discussion - not so
much because of the AppArmor test itself - but because I think this
patch offers a good place to discuss how we should/will need to handle
code visibility for the purpose of writing tests.

I fully expect there to be a great deal of discussion on this patch
especially on the topic of visibility and how to expose symbols for
testing. Based on conversations I had before sending this patch out, I
expect to see a number of different suggestions on how to test symbols
that are not normally exposed.
---
 security/apparmor/Kconfig                 |  17 +
 security/apparmor/Makefile                |   1 +
 security/apparmor/include/policy_unpack.h |  53 ++
 security/apparmor/policy_unpack.c         |  61 +--
 security/apparmor/policy_unpack_test.c    | 607 ++++++++++++++++++++++
 5 files changed, 687 insertions(+), 52 deletions(-)
 create mode 100644 security/apparmor/policy_unpack_test.c

diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig
index d8b1a360a636..632fbb873389 100644
--- a/security/apparmor/Kconfig
+++ b/security/apparmor/Kconfig
@@ -66,3 +66,20 @@ config SECURITY_APPARMOR_DEBUG_MESSAGES
 	  Set the default value of the apparmor.debug kernel parameter.
 	  When enabled, various debug messages will be logged to
 	  the kernel message buffer.
+
+config SECURITY_APPARMOR_TEST
+	bool "Build KUnit tests for policy_unpack.c"
+	default n
+	depends on KUNIT && SECURITY_APPARMOR
+	help
+	  This builds the AppArmor KUnit tests.
+
+	  KUnit tests run during boot and output the results to the debug log
+	  in TAP format (http://testanything.org/). Only useful for kernel devs
+	  running KUnit test harness and are not for inclusion into a
+	  production build.
+
+	  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.
diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
index ff23fcfefe19..7ac1fc2dc045 100644
--- a/security/apparmor/Makefile
+++ b/security/apparmor/Makefile
@@ -2,6 +2,7 @@
 # Makefile for AppArmor Linux Security Module
 #
 obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o
+obj-$(CONFIG_SECURITY_APPARMOR_TEST) += policy_unpack_test.o
 
 apparmor-y := apparmorfs.o audit.o capability.o task.o ipc.o lib.o match.o \
               path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \
diff --git a/security/apparmor/include/policy_unpack.h b/security/apparmor/include/policy_unpack.h
index 46aefae918f5..dc272bafee2b 100644
--- a/security/apparmor/include/policy_unpack.h
+++ b/security/apparmor/include/policy_unpack.h
@@ -16,6 +16,59 @@
 #include <linux/dcache.h>
 #include <linux/workqueue.h>
 
+/*
+ * The AppArmor interface treats data as a type byte followed by the
+ * actual data.  The interface has the notion of a a named entry
+ * which has a name (AA_NAME typecode followed by name string) followed by
+ * the entries typecode and data.  Named types allow for optional
+ * elements and extensions to be added and tested for without breaking
+ * backwards compatibility.
+ */
+
+enum aa_code {
+	AA_U8,
+	AA_U16,
+	AA_U32,
+	AA_U64,
+	AA_NAME,		/* same as string except it is items name */
+	AA_STRING,
+	AA_BLOB,
+	AA_STRUCT,
+	AA_STRUCTEND,
+	AA_LIST,
+	AA_LISTEND,
+	AA_ARRAY,
+	AA_ARRAYEND,
+};
+
+/*
+ * aa_ext is the read of the buffer containing the serialized profile.  The
+ * data is copied into a kernel buffer in apparmorfs and then handed off to
+ * the unpack routines.
+ */
+struct aa_ext {
+	void *start;
+	void *end;
+	void *pos;		/* pointer to current position in the buffer */
+	u32 version;
+};
+
+/* test if read will be in packed data bounds */
+static inline bool inbounds(struct aa_ext *e, size_t size)
+{
+	return (size <= e->end - e->pos);
+}
+
+size_t unpack_u16_chunk(struct aa_ext *e, char **chunk);
+bool unpack_X(struct aa_ext *e, enum aa_code code);
+bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name);
+bool unpack_u32(struct aa_ext *e, u32 *data, const char *name);
+bool unpack_u64(struct aa_ext *e, u64 *data, const char *name);
+size_t unpack_array(struct aa_ext *e, const char *name);
+size_t unpack_blob(struct aa_ext *e, char **blob, const char *name);
+int unpack_str(struct aa_ext *e, const char **string, const char *name);
+int unpack_strdup(struct aa_ext *e, char **string, const char *name);
+
 struct aa_load_ent {
 	struct list_head list;
 	struct aa_profile *new;
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 8cfc9493eefc..7811e9b7a154 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -36,43 +36,6 @@
 #define v7	7
 #define v8	8	/* full network masking */
 
-/*
- * The AppArmor interface treats data as a type byte followed by the
- * actual data.  The interface has the notion of a a named entry
- * which has a name (AA_NAME typecode followed by name string) followed by
- * the entries typecode and data.  Named types allow for optional
- * elements and extensions to be added and tested for without breaking
- * backwards compatibility.
- */
-
-enum aa_code {
-	AA_U8,
-	AA_U16,
-	AA_U32,
-	AA_U64,
-	AA_NAME,		/* same as string except it is items name */
-	AA_STRING,
-	AA_BLOB,
-	AA_STRUCT,
-	AA_STRUCTEND,
-	AA_LIST,
-	AA_LISTEND,
-	AA_ARRAY,
-	AA_ARRAYEND,
-};
-
-/*
- * aa_ext is the read of the buffer containing the serialized profile.  The
- * data is copied into a kernel buffer in apparmorfs and then handed off to
- * the unpack routines.
- */
-struct aa_ext {
-	void *start;
-	void *end;
-	void *pos;		/* pointer to current position in the buffer */
-	u32 version;
-};
-
 /* audit callback for unpack fields */
 static void audit_cb(struct audit_buffer *ab, void *va)
 {
@@ -194,12 +157,6 @@ struct aa_loaddata *aa_loaddata_alloc(size_t size)
 	return d;
 }
 
-/* test if read will be in packed data bounds */
-static bool inbounds(struct aa_ext *e, size_t size)
-{
-	return (size <= e->end - e->pos);
-}
-
 static void *kvmemdup(const void *src, size_t len)
 {
 	void *p = kvmalloc(len, GFP_KERNEL);
@@ -216,7 +173,7 @@ static void *kvmemdup(const void *src, size_t len)
  *
  * Returns: the size of chunk found with the read head at the end of the chunk.
  */
-static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
+size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
 {
 	size_t size = 0;
 	void *pos = e->pos;
@@ -237,7 +194,7 @@ static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
 }
 
 /* unpack control byte */
-static bool unpack_X(struct aa_ext *e, enum aa_code code)
+bool unpack_X(struct aa_ext *e, enum aa_code code)
 {
 	if (!inbounds(e, 1))
 		return 0;
@@ -263,7 +220,7 @@ static bool unpack_X(struct aa_ext *e, enum aa_code code)
  *
  * Returns: 0 if either match fails, the read head does not move
  */
-static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
+bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
 {
 	/*
 	 * May need to reset pos if name or type doesn't match
@@ -311,7 +268,7 @@ static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name)
 	return 0;
 }
 
-static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
+bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
 {
 	void *pos = e->pos;
 
@@ -329,7 +286,7 @@ static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
 	return 0;
 }
 
-static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
+bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
 {
 	void *pos = e->pos;
 
@@ -347,7 +304,7 @@ static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
 	return 0;
 }
 
-static size_t unpack_array(struct aa_ext *e, const char *name)
+size_t unpack_array(struct aa_ext *e, const char *name)
 {
 	void *pos = e->pos;
 
@@ -365,7 +322,7 @@ static size_t unpack_array(struct aa_ext *e, const char *name)
 	return 0;
 }
 
-static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
+size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
 {
 	void *pos = e->pos;
 
@@ -387,7 +344,7 @@ static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
 	return 0;
 }
 
-static int unpack_str(struct aa_ext *e, const char **string, const char *name)
+int unpack_str(struct aa_ext *e, const char **string, const char *name)
 {
 	char *src_str;
 	size_t size = 0;
@@ -410,7 +367,7 @@ static int unpack_str(struct aa_ext *e, const char **string, const char *name)
 	return 0;
 }
 
-static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
+int unpack_strdup(struct aa_ext *e, char **string, const char *name)
 {
 	const char *tmp;
 	void *pos = e->pos;
diff --git a/security/apparmor/policy_unpack_test.c b/security/apparmor/policy_unpack_test.c
new file mode 100644
index 000000000000..3907f7d642e6
--- /dev/null
+++ b/security/apparmor/policy_unpack_test.c
@@ -0,0 +1,607 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit tests for AppArmor's policy unpack.
+ */
+
+#include <kunit/test.h>
+
+#include "include/policy.h"
+#include "include/policy_unpack.h"
+
+#define TEST_STRING_NAME "TEST_STRING"
+#define TEST_STRING_DATA "testing"
+#define TEST_STRING_BUF_OFFSET \
+	(3 + strlen(TEST_STRING_NAME) + 1)
+
+#define TEST_U32_NAME "U32_TEST"
+#define TEST_U32_DATA ((u32)0x01020304)
+#define TEST_NAMED_U32_BUF_OFFSET \
+	(TEST_STRING_BUF_OFFSET + 3 + strlen(TEST_STRING_DATA) + 1)
+#define TEST_U32_BUF_OFFSET \
+	(TEST_NAMED_U32_BUF_OFFSET + 3 + strlen(TEST_U32_NAME) + 1)
+
+#define TEST_U16_OFFSET (TEST_U32_BUF_OFFSET + 3)
+#define TEST_U16_DATA ((u16)(TEST_U32_DATA >> 16))
+
+#define TEST_U64_NAME "U64_TEST"
+#define TEST_U64_DATA ((u64)0x0102030405060708)
+#define TEST_NAMED_U64_BUF_OFFSET (TEST_U32_BUF_OFFSET + sizeof(u32) + 1)
+#define TEST_U64_BUF_OFFSET \
+	(TEST_NAMED_U64_BUF_OFFSET + 3 + strlen(TEST_U64_NAME) + 1)
+
+#define TEST_BLOB_NAME "BLOB_TEST"
+#define TEST_BLOB_DATA "\xde\xad\x00\xbe\xef"
+#define TEST_BLOB_DATA_SIZE (ARRAY_SIZE(TEST_BLOB_DATA))
+#define TEST_NAMED_BLOB_BUF_OFFSET (TEST_U64_BUF_OFFSET + sizeof(u64) + 1)
+#define TEST_BLOB_BUF_OFFSET \
+	(TEST_NAMED_BLOB_BUF_OFFSET + 3 + strlen(TEST_BLOB_NAME) + 1)
+
+#define TEST_ARRAY_NAME "ARRAY_TEST"
+#define TEST_ARRAY_SIZE 16
+#define TEST_NAMED_ARRAY_BUF_OFFSET \
+	(TEST_BLOB_BUF_OFFSET + 5 + TEST_BLOB_DATA_SIZE)
+#define TEST_ARRAY_BUF_OFFSET \
+	(TEST_NAMED_ARRAY_BUF_OFFSET + 3 + strlen(TEST_ARRAY_NAME) + 1)
+
+struct policy_unpack_fixture {
+	struct aa_ext *e;
+	size_t e_size;
+};
+
+struct aa_ext *build_aa_ext_struct(struct policy_unpack_fixture *puf,
+				   struct kunit *test, size_t buf_size)
+{
+	char *buf;
+	struct aa_ext *e;
+
+	buf = kunit_kzalloc(test, buf_size, GFP_USER);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, buf);
+
+	e = kunit_kmalloc(test, sizeof(*e), GFP_USER);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, e);
+
+	e->start = buf;
+	e->end = e->start + buf_size;
+	e->pos = e->start;
+
+	*buf = AA_NAME;
+	*(buf + 1) = strlen(TEST_STRING_NAME) + 1;
+	strcpy(buf + 3, TEST_STRING_NAME);
+
+	buf = e->start + TEST_STRING_BUF_OFFSET;
+	*buf = AA_STRING;
+	*(buf + 1) = strlen(TEST_STRING_DATA) + 1;
+	strcpy(buf + 3, TEST_STRING_DATA);
+
+	buf = e->start + TEST_NAMED_U32_BUF_OFFSET;
+	*buf = AA_NAME;
+	*(buf + 1) = strlen(TEST_U32_NAME) + 1;
+	strcpy(buf + 3, TEST_U32_NAME);
+	*(buf + 3 + strlen(TEST_U32_NAME) + 1) = AA_U32;
+	*((u32 *)(buf + 3 + strlen(TEST_U32_NAME) + 2)) = TEST_U32_DATA;
+
+	buf = e->start + TEST_NAMED_U64_BUF_OFFSET;
+	*buf = AA_NAME;
+	*(buf + 1) = strlen(TEST_U64_NAME) + 1;
+	strcpy(buf + 3, TEST_U64_NAME);
+	*(buf + 3 + strlen(TEST_U64_NAME) + 1) = AA_U64;
+	*((u64 *)(buf + 3 + strlen(TEST_U64_NAME) + 2)) = TEST_U64_DATA;
+
+	buf = e->start + TEST_NAMED_BLOB_BUF_OFFSET;
+	*buf = AA_NAME;
+	*(buf + 1) = strlen(TEST_BLOB_NAME) + 1;
+	strcpy(buf + 3, TEST_BLOB_NAME);
+	*(buf + 3 + strlen(TEST_BLOB_NAME) + 1) = AA_BLOB;
+	*(buf + 3 + strlen(TEST_BLOB_NAME) + 2) = TEST_BLOB_DATA_SIZE;
+	memcpy(buf + 3 + strlen(TEST_BLOB_NAME) + 6,
+		TEST_BLOB_DATA, TEST_BLOB_DATA_SIZE);
+
+	buf = e->start + TEST_NAMED_ARRAY_BUF_OFFSET;
+	*buf = AA_NAME;
+	*(buf + 1) = strlen(TEST_ARRAY_NAME) + 1;
+	strcpy(buf + 3, TEST_ARRAY_NAME);
+	*(buf + 3 + strlen(TEST_ARRAY_NAME) + 1) = AA_ARRAY;
+	*((u16 *)(buf + 3 + strlen(TEST_ARRAY_NAME) + 2)) = TEST_ARRAY_SIZE;
+
+	return e;
+}
+
+static int policy_unpack_test_init(struct kunit *test)
+{
+	size_t e_size = TEST_ARRAY_BUF_OFFSET + sizeof(u16) + 1;
+	struct policy_unpack_fixture *puf;
+
+	puf = kunit_kmalloc(test, sizeof(*puf), GFP_USER);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, puf);
+
+	puf->e_size = e_size;
+	puf->e = build_aa_ext_struct(puf, test, e_size);
+
+	test->priv = puf;
+	return 0;
+}
+
+static void policy_unpack_test_inbounds_when_inbounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+
+	KUNIT_EXPECT_TRUE(test, inbounds(puf->e, 0));
+	KUNIT_EXPECT_TRUE(test, inbounds(puf->e, puf->e_size / 2));
+	KUNIT_EXPECT_TRUE(test, inbounds(puf->e, puf->e_size));
+}
+
+static void policy_unpack_test_inbounds_when_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+
+	KUNIT_EXPECT_FALSE(test, inbounds(puf->e, puf->e_size + 1));
+}
+
+static void policy_unpack_test_unpack_array_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	u16 array_size;
+
+	puf->e->pos += TEST_ARRAY_BUF_OFFSET;
+
+	array_size = unpack_array(puf->e, NULL);
+
+	KUNIT_EXPECT_EQ(test, array_size, (u16)TEST_ARRAY_SIZE);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+		puf->e->start + TEST_ARRAY_BUF_OFFSET + sizeof(u16) + 1);
+}
+
+static void policy_unpack_test_unpack_array_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_ARRAY_NAME;
+	u16 array_size;
+
+	puf->e->pos += TEST_NAMED_ARRAY_BUF_OFFSET;
+
+	array_size = unpack_array(puf->e, name);
+
+	KUNIT_EXPECT_EQ(test, array_size, (u16)TEST_ARRAY_SIZE);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+		puf->e->start + TEST_ARRAY_BUF_OFFSET + sizeof(u16) + 1);
+}
+
+static void policy_unpack_test_unpack_array_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_ARRAY_NAME;
+	u16 array_size;
+
+	puf->e->pos += TEST_NAMED_ARRAY_BUF_OFFSET;
+	puf->e->end = puf->e->start + TEST_ARRAY_BUF_OFFSET + sizeof(u16);
+
+	array_size = unpack_array(puf->e, name);
+
+	KUNIT_EXPECT_EQ(test, array_size, (u16)0);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+		puf->e->start + TEST_NAMED_ARRAY_BUF_OFFSET);
+}
+
+static void policy_unpack_test_unpack_blob_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *blob = NULL;
+	size_t size;
+
+	puf->e->pos += TEST_BLOB_BUF_OFFSET;
+	size = unpack_blob(puf->e, &blob, NULL);
+
+	KUNIT_EXPECT_EQ(test, size, TEST_BLOB_DATA_SIZE);
+	KUNIT_EXPECT_TRUE(test,
+		memcmp(blob, TEST_BLOB_DATA, TEST_BLOB_DATA_SIZE) == 0);
+}
+
+static void policy_unpack_test_unpack_blob_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *blob = NULL;
+	size_t size;
+
+	puf->e->pos += TEST_NAMED_BLOB_BUF_OFFSET;
+	size = unpack_blob(puf->e, &blob, TEST_BLOB_NAME);
+
+	KUNIT_EXPECT_EQ(test, size, TEST_BLOB_DATA_SIZE);
+	KUNIT_EXPECT_TRUE(test,
+		memcmp(blob, TEST_BLOB_DATA, TEST_BLOB_DATA_SIZE) == 0);
+}
+
+static void policy_unpack_test_unpack_blob_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *blob = NULL;
+	void *start;
+	int size;
+
+	puf->e->pos += TEST_NAMED_BLOB_BUF_OFFSET;
+	start = puf->e->pos;
+	puf->e->end = puf->e->start + TEST_BLOB_BUF_OFFSET
+		+ TEST_BLOB_DATA_SIZE - 1;
+
+	size = unpack_blob(puf->e, &blob, TEST_BLOB_NAME);
+
+	KUNIT_EXPECT_EQ(test, size, 0);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, start);
+}
+
+static void policy_unpack_test_unpack_str_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char *string = NULL;
+	size_t size;
+
+	puf->e->pos += TEST_STRING_BUF_OFFSET;
+	size = unpack_str(puf->e, &string, NULL);
+
+	KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1);
+	KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA);
+}
+
+static void policy_unpack_test_unpack_str_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char *string = NULL;
+	size_t size;
+
+	size = unpack_str(puf->e, &string, TEST_STRING_NAME);
+
+	KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1);
+	KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA);
+}
+
+static void policy_unpack_test_unpack_str_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char *string = NULL;
+	void *start = puf->e->pos;
+	int size;
+
+	puf->e->end = puf->e->pos + TEST_STRING_BUF_OFFSET
+		+ strlen(TEST_STRING_DATA) - 1;
+
+	size = unpack_str(puf->e, &string, TEST_STRING_NAME);
+
+	KUNIT_EXPECT_EQ(test, size, 0);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, start);
+}
+
+static void policy_unpack_test_unpack_strdup_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *string = NULL;
+	size_t size;
+
+	puf->e->pos += TEST_STRING_BUF_OFFSET;
+	size = unpack_strdup(puf->e, &string, NULL);
+
+	KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1);
+	KUNIT_EXPECT_FALSE(test,
+			   ((uintptr_t)puf->e->start <= (uintptr_t)string)
+			   && ((uintptr_t)string <= (uintptr_t)puf->e->end));
+	KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA);
+}
+
+static void policy_unpack_test_unpack_strdup_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *string = NULL;
+	size_t size;
+
+	size = unpack_strdup(puf->e, &string, TEST_STRING_NAME);
+
+	KUNIT_EXPECT_EQ(test, size, strlen(TEST_STRING_DATA) + 1);
+	KUNIT_EXPECT_FALSE(test,
+			   ((uintptr_t)puf->e->start <= (uintptr_t)string)
+			   && ((uintptr_t)string <= (uintptr_t)puf->e->end));
+	KUNIT_EXPECT_STREQ(test, string, TEST_STRING_DATA);
+}
+
+static void policy_unpack_test_unpack_strdup_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	void *start = puf->e->pos;
+	char *string = NULL;
+	int size;
+
+	puf->e->end = puf->e->pos + TEST_STRING_BUF_OFFSET
+		+ strlen(TEST_STRING_DATA) - 1;
+
+	size = unpack_strdup(puf->e, &string, TEST_STRING_NAME);
+
+	KUNIT_EXPECT_EQ(test, size, 0);
+	KUNIT_EXPECT_PTR_EQ(test, string, (char *)NULL);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, start);
+}
+
+static void policy_unpack_test_unpack_nameX_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success;
+
+	puf->e->pos += TEST_U32_BUF_OFFSET;
+
+	success = unpack_nameX(puf->e, AA_U32, NULL);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			    puf->e->start + TEST_U32_BUF_OFFSET + 1);
+}
+
+static void policy_unpack_test_unpack_nameX_with_wrong_code(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success;
+
+	puf->e->pos += TEST_U32_BUF_OFFSET;
+
+	success = unpack_nameX(puf->e, AA_BLOB, NULL);
+
+	KUNIT_EXPECT_FALSE(test, success);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			    puf->e->start + TEST_U32_BUF_OFFSET);
+}
+
+static void policy_unpack_test_unpack_nameX_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_U32_NAME;
+	bool success;
+
+	puf->e->pos += TEST_NAMED_U32_BUF_OFFSET;
+
+	success = unpack_nameX(puf->e, AA_U32, name);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			    puf->e->start + TEST_U32_BUF_OFFSET + 1);
+}
+
+static void policy_unpack_test_unpack_nameX_with_wrong_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	static const char name[] = "12345678";
+	bool success;
+
+	puf->e->pos += TEST_NAMED_U32_BUF_OFFSET;
+
+	success = unpack_nameX(puf->e, AA_U32, name);
+
+	KUNIT_EXPECT_FALSE(test, success);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			    puf->e->start + TEST_NAMED_U32_BUF_OFFSET);
+}
+
+static void policy_unpack_test_unpack_u16_chunk_basic(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *chunk = NULL;
+	size_t size;
+
+	puf->e->pos += TEST_U16_OFFSET;
+	/*
+	 * WARNING: For unit testing purposes, we're pushing puf->e->end past
+	 * the end of the allocated memory. Doing anything other than comparing
+	 * memory addresses is dangerous.
+	 */
+	puf->e->end += TEST_U16_DATA;
+
+	size = unpack_u16_chunk(puf->e, &chunk);
+
+	KUNIT_EXPECT_PTR_EQ(test, (void *)chunk,
+			    puf->e->start + TEST_U16_OFFSET + 2);
+	KUNIT_EXPECT_EQ(test, size, (size_t)TEST_U16_DATA);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, (void *)(chunk + TEST_U16_DATA));
+}
+
+static void policy_unpack_test_unpack_u16_chunk_out_of_bounds_1(
+		struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *chunk = NULL;
+	size_t size;
+
+	puf->e->pos = puf->e->end - 1;
+
+	size = unpack_u16_chunk(puf->e, &chunk);
+
+	KUNIT_EXPECT_EQ(test, size, (size_t)0);
+	KUNIT_EXPECT_PTR_EQ(test, chunk, (char *)NULL);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, puf->e->end - 1);
+}
+
+static void policy_unpack_test_unpack_u16_chunk_out_of_bounds_2(
+		struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	char *chunk = NULL;
+	size_t size;
+
+	puf->e->pos += TEST_U16_OFFSET;
+	/*
+	 * WARNING: For unit testing purposes, we're pushing puf->e->end past
+	 * the end of the allocated memory. Doing anything other than comparing
+	 * memory addresses is dangerous.
+	 */
+	puf->e->end = puf->e->pos + TEST_U16_DATA - 1;
+
+	size = unpack_u16_chunk(puf->e, &chunk);
+
+	KUNIT_EXPECT_EQ(test, size, (size_t)0);
+	KUNIT_EXPECT_PTR_EQ(test, chunk, (char *)NULL);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos, puf->e->start + TEST_U16_OFFSET);
+}
+
+static void policy_unpack_test_unpack_u32_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success;
+	u32 data;
+
+	puf->e->pos += TEST_U32_BUF_OFFSET;
+
+	success = unpack_u32(puf->e, &data, NULL);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_EQ(test, data, TEST_U32_DATA);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			puf->e->start + TEST_U32_BUF_OFFSET + sizeof(u32) + 1);
+}
+
+static void policy_unpack_test_unpack_u32_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_U32_NAME;
+	bool success;
+	u32 data;
+
+	puf->e->pos += TEST_NAMED_U32_BUF_OFFSET;
+
+	success = unpack_u32(puf->e, &data, name);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_EQ(test, data, TEST_U32_DATA);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			puf->e->start + TEST_U32_BUF_OFFSET + sizeof(u32) + 1);
+}
+
+static void policy_unpack_test_unpack_u32_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_U32_NAME;
+	bool success;
+	u32 data;
+
+	puf->e->pos += TEST_NAMED_U32_BUF_OFFSET;
+	puf->e->end = puf->e->start + TEST_U32_BUF_OFFSET + sizeof(u32);
+
+	success = unpack_u32(puf->e, &data, name);
+
+	KUNIT_EXPECT_FALSE(test, success);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			puf->e->start + TEST_NAMED_U32_BUF_OFFSET);
+}
+
+static void policy_unpack_test_unpack_u64_with_null_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success;
+	u64 data;
+
+	puf->e->pos += TEST_U64_BUF_OFFSET;
+
+	success = unpack_u64(puf->e, &data, NULL);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_EQ(test, data, TEST_U64_DATA);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			puf->e->start + TEST_U64_BUF_OFFSET + sizeof(u64) + 1);
+}
+
+static void policy_unpack_test_unpack_u64_with_name(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_U64_NAME;
+	bool success;
+	u64 data;
+
+	puf->e->pos += TEST_NAMED_U64_BUF_OFFSET;
+
+	success = unpack_u64(puf->e, &data, name);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_EQ(test, data, TEST_U64_DATA);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			puf->e->start + TEST_U64_BUF_OFFSET + sizeof(u64) + 1);
+}
+
+static void policy_unpack_test_unpack_u64_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	const char name[] = TEST_U64_NAME;
+	bool success;
+	u64 data;
+
+	puf->e->pos += TEST_NAMED_U64_BUF_OFFSET;
+	puf->e->end = puf->e->start + TEST_U64_BUF_OFFSET + sizeof(u64);
+
+	success = unpack_u64(puf->e, &data, name);
+
+	KUNIT_EXPECT_FALSE(test, success);
+	KUNIT_EXPECT_PTR_EQ(test, puf->e->pos,
+			puf->e->start + TEST_NAMED_U64_BUF_OFFSET);
+}
+
+static void policy_unpack_test_unpack_X_code_match(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success = unpack_X(puf->e, AA_NAME);
+
+	KUNIT_EXPECT_TRUE(test, success);
+	KUNIT_EXPECT_TRUE(test, puf->e->pos == puf->e->start + 1);
+}
+
+static void policy_unpack_test_unpack_X_code_mismatch(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success = unpack_X(puf->e, AA_STRING);
+
+	KUNIT_EXPECT_FALSE(test, success);
+	KUNIT_EXPECT_TRUE(test, puf->e->pos == puf->e->start);
+}
+
+static void policy_unpack_test_unpack_X_out_of_bounds(struct kunit *test)
+{
+	struct policy_unpack_fixture *puf = test->priv;
+	bool success;
+
+	puf->e->pos = puf->e->end;
+	success = unpack_X(puf->e, AA_NAME);
+
+	KUNIT_EXPECT_FALSE(test, success);
+}
+
+static struct kunit_case apparmor_policy_unpack_test_cases[] = {
+	KUNIT_CASE(policy_unpack_test_inbounds_when_inbounds),
+	KUNIT_CASE(policy_unpack_test_inbounds_when_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_array_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_array_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_array_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_blob_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_blob_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_blob_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_nameX_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_nameX_with_wrong_code),
+	KUNIT_CASE(policy_unpack_test_unpack_nameX_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_nameX_with_wrong_name),
+	KUNIT_CASE(policy_unpack_test_unpack_str_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_str_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_str_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_strdup_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_strdup_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_strdup_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_u16_chunk_basic),
+	KUNIT_CASE(policy_unpack_test_unpack_u16_chunk_out_of_bounds_1),
+	KUNIT_CASE(policy_unpack_test_unpack_u16_chunk_out_of_bounds_2),
+	KUNIT_CASE(policy_unpack_test_unpack_u32_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_u32_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_u32_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_u64_with_null_name),
+	KUNIT_CASE(policy_unpack_test_unpack_u64_with_name),
+	KUNIT_CASE(policy_unpack_test_unpack_u64_out_of_bounds),
+	KUNIT_CASE(policy_unpack_test_unpack_X_code_match),
+	KUNIT_CASE(policy_unpack_test_unpack_X_code_mismatch),
+	KUNIT_CASE(policy_unpack_test_unpack_X_out_of_bounds),
+	{},
+};
+
+static struct kunit_suite apparmor_policy_unpack_test_module = {
+	.name = "apparmor_policy_unpack",
+	.init = policy_unpack_test_init,
+	.test_cases = apparmor_policy_unpack_test_cases,
+};
+
+kunit_test_suite(apparmor_policy_unpack_test_module);
-- 
2.23.0.866.gb869b98d4c-goog