[PATCH AUTOSEL 5.13 84/88] kasan: test: disable kmalloc_memmove_invalid_size for HW_TAGS

[Sasha Levin]

From: Andrey Konovalov <andreyknvl@xxxxxxxxx>

[ Upstream commit 1b0668be62cfa394903bb368641c80533bf42d5a ]

The HW_TAGS mode doesn't check memmove for negative size.  As a result,
the kmalloc_memmove_invalid_size test corrupts memory, which can result in
a crash.

Disable this test with HW_TAGS KASAN.

Link: https://lkml.kernel.org/r/088733a06ac21eba29aa85b6f769d2abd74f9638.1628779805.git.andreyknvl@xxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 lib/test_kasan.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 9a6eb3c9dc49..00b7061edf59 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -490,11 +490,17 @@ static void kmalloc_memmove_invalid_size(struct kunit *test)
 	size_t size = 64;
 	volatile size_t invalid_size = -2;
 
+	/*
+	 * Hardware tag-based mode doesn't check memmove for negative size.
+	 * As a result, this test introduces a side-effect memory corruption,
+	 * which can result in a crash.
+	 */
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
+
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
 	memset((char *)ptr, 0, 64);
-
 	KUNIT_EXPECT_KASAN_FAIL(test,
 		memmove((char *)ptr, (char *)ptr + 4, invalid_size));
 	kfree(ptr);
-- 
2.30.2