Re: [PATCH 08/11] kasan: adopt kmalloc_uaf2 test to HW_TAGS mode

From: Alexander Potapenko
Date: Tue Jan 12 2021 - 03:27:02 EST


Nit: s/adopt/adapt in the title.


> +again:
> ptr1 = kmalloc(size, GFP_KERNEL);
> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
>
> @@ -384,6 +386,13 @@ static void kmalloc_uaf2(struct kunit *test)
> ptr2 = kmalloc(size, GFP_KERNEL);
> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
>
> + /*
> + * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
> + * Allow up to 4 attempts at generating different tags.
> + */
> + if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 4)
> + goto again;
> +

Looks like we are leaking memory allocated for ptr2 here?