kasan: adjust kasan_stack_oob for tag-based mode

Use OOB_TAG_OFF as access offset to land the access into the next granule.

Suggested-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: http://lkml.kernel.org/r/403b259f1de49a7a3694531c851ac28326a586a8.1596199677.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/3063ab1411e92bce36061a96e25b651212e70ba6.1596544734.git.andreyknvl@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index f362f26629381f15215d9712d8c69c5d03fb8885..53e953bb1d1daf21d14e570e7225fe0b5c900334 100644 (file)
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -488,7 +488,7 @@ static noinline void __init kasan_global_oob(void)
 static noinline void __init kasan_stack_oob(void)
 {
        char stack_array[10];
-       volatile int i = 0;
+       volatile int i = OOB_TAG_OFF;
        char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
 
        pr_info("out-of-bounds on stack\n");