[PATCH] kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller

[Nihar Chaithanya]

The Kunit tests for kmalloc_track_caller and kmalloc_node_track_caller
are missing in kasan_test_c.c, which check that these functions poison
the memory properly.

Add a Kunit test:
-> kmalloc_tracker_caller_oob_right(): This includes unaligned, aligned and
   beyond-aligned out-of-bounds access test for kmalloc_track_caller and
   out-of-bounds access test for kmalloc_node_track_caller.

Signed-off-by: Nihar Chaithanya <niharchaithanya@xxxxxxxxx>
---
 mm/kasan/kasan_test_c.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
index a181e4780d9d..b418bdff5bdb 100644
--- a/mm/kasan/kasan_test_c.c
+++ b/mm/kasan/kasan_test_c.c
@@ -213,6 +213,39 @@ static void kmalloc_node_oob_right(struct kunit *test)
 	kfree(ptr);
 }
 
+static void kmalloc_track_caller_oob_right(struct kunit *test)
+{
+	char *ptr;
+	size_t size = 128 - KASAN_GRANULE_SIZE - 5;
+
+	/*
+	 * Check that KASAN detects out-of-bounds access for object allocated via
+	 * kmalloc_track_caller().
+	 */
+	ptr = kmalloc_track_caller(size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+	OPTIMIZER_HIDE_VAR(ptr);
+	if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+		KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y');
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] =
+					ptr[size + KASAN_GRANULE_SIZE + 5]);
+	kfree(ptr);
+
+	/*
+	 * Check that KASAN detects out-of-bounds access for object allocated via
+	 * kmalloc_node_track_caller().
+	 */
+	size = 4096;
+	ptr = kmalloc_node_track_caller(size, GFP_KERNEL, 0);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+	OPTIMIZER_HIDE_VAR(ptr);
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
+	kfree(ptr);
+}
+
 /*
  * Check that KASAN detects an out-of-bounds access for a big object allocated
  * via kmalloc(). But not as big as to trigger the page_alloc fallback.
@@ -1958,6 +1991,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kmalloc_oob_right),
 	KUNIT_CASE(kmalloc_oob_left),
 	KUNIT_CASE(kmalloc_node_oob_right),
+	KUNIT_CASE(kmalloc_track_caller_oob_right),
 	KUNIT_CASE(kmalloc_big_oob_right),
 	KUNIT_CASE(kmalloc_large_oob_right),
 	KUNIT_CASE(kmalloc_large_uaf),
-- 
2.34.1