2019-10-29 07:25:03

by Daniel Axtens

Subject: [PATCH v10 2/5] kasan: add test for vmalloc

Test kasan vmalloc support by adding a new test to the module.

Signed-off-by: Daniel Axtens <[email protected]>

--

v5: split out per Christophe Leroy
---
lib/test_kasan.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 49cc4d570a40..328d33beae36 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -19,6 +19,7 @@
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/io.h>
+#include <linux/vmalloc.h>

#include <asm/page.h>

@@ -748,6 +749,30 @@ static noinline void __init kmalloc_double_kzfree(void)
kzfree(ptr);
}

+#ifdef CONFIG_KASAN_VMALLOC
+static noinline void __init vmalloc_oob(void)
+{
+ void *area;
+
+ pr_info("vmalloc out-of-bounds\n");
+
+ /*
+ * We have to be careful not to hit the guard page.
+ * The MMU will catch that and crash us.
+ */
+ area = vmalloc(3000);
+ if (!area) {
+ pr_err("Allocation failed\n");
+ return;
+ }
+
+ ((volatile char *)area)[3100];
+ vfree(area);
+}
+#else
+static void __init vmalloc_oob(void) {}
+#endif
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -793,6 +818,7 @@ static int __init kmalloc_tests_init(void)
kasan_strings();
kasan_bitops();
kmalloc_double_kzfree();
+ vmalloc_oob();

kasan_restore_multi_shot(multishot);

--
2.20.1

2019-10-29 16:45:47

by Andrey Ryabinin

Subject: Re: [PATCH v10 2/5] kasan: add test for vmalloc

On 10/29/19 7:20 AM, Daniel Axtens wrote:
> Test kasan vmalloc support by adding a new test to the module.
>
> Signed-off-by: Daniel Axtens <[email protected]>
>

Reviewed-by: Andrey Ryabinin <[email protected]>