kasan: test: disable kmalloc_memmove_invalid_size for HW_TAGS

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@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index db73bc9..1f533a7 100644 (file)
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -501,11 +501,17 @@ 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);