[PATCH v4 3/5] lib/test_kasan: Add test for double-kzfree detection

Marco Elver
2019-06-27T09:45:17Z

Adds a simple test that checks if double-kzfree is being detected
correctly.

Signed-off-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: kasan-dev@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
---
lib/test_kasan.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index e3c593c38eff..dda5da9f5bd4 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -619,6 +619,22 @@ static noinline void __init kasan_strings(void)
strnlen(ptr, 1);
}

+static noinline void __init kmalloc_double_kzfree(void)
+{
+ char *ptr;
+ size_t size = 16;
+
+ pr_info("double-free (kzfree)\n");
+ ptr = kmalloc(size, GFP_KERNEL);
+ if (!ptr) {
+ pr_err("Allocation failed\n");
+ return;
+ }
+
+ kzfree(ptr);
+ kzfree(ptr);
+}
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -660,6 +676,7 @@ static int __init kmalloc_tests_init(void)
kasan_memchr();
kasan_memcmp();
kasan_strings();
+ kmalloc_double_kzfree();

kasan_restore_multi_shot(multishot);

--
2.22.0.410.gd8fdbe21b5-goog