[PATCH v2 2/2] mm, kasan: add a ksize() test

From: Alexander Potapenko
Date: Wed Apr 13 2016 - 07:21:12 EST


Add a test that makes sure ksize() unpoisons the whole chunk.

Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
---
v2: - splitted v1 into two patches
---
lib/test_kasan.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 82169fb..48e5a0b 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -344,6 +344,25 @@ static noinline void __init kasan_stack_oob(void)
*(volatile char *)p;
}

+static noinline void __init ksize_unpoisons_memory(void)
+{
+ char *ptr;
+ size_t size = 123, real_size = size;
+
+ pr_info("ksize() unpoisons the whole allocated chunk\n");
+ ptr = kmalloc(size, GFP_KERNEL);
+ if (!ptr) {
+ pr_err("Allocation failed\n");
+ return;
+ }
+ real_size = ksize(ptr);
+ /* This access doesn't trigger an error. */
+ ptr[size] = 'x';
+ /* This one does. */
+ ptr[real_size] = 'y';
+ kfree(ptr);
+}
+
static int __init kmalloc_tests_init(void)
{
kmalloc_oob_right();
@@ -367,6 +386,7 @@ static int __init kmalloc_tests_init(void)
kmem_cache_oob();
kasan_stack_oob();
kasan_global_oob();
+ ksize_unpoisons_memory();
return -EAGAIN;
}

--
2.8.0.rc3.226.g39d4020