[PATCH 5/8] kasan: test: only do kmalloc_uaf_memset for generic mode

From: andrey . konovalov
Date: Wed Aug 11 2021 - 15:21:56 EST


From: Andrey Konovalov <andreyknvl@xxxxxxxxx>

kmalloc_uaf_memset() writes to freed memory, which is only safe with the
GENERIC mode (as it uses quarantine). For other modes, this test corrupts
kernel memory, which might result in a crash.

Only enable kmalloc_uaf_memset() for the GENERIC mode.

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
---
lib/test_kasan.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 0b5698cd7d1d..efd0da5c750f 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -528,6 +528,12 @@ static void kmalloc_uaf_memset(struct kunit *test)
char *ptr;
size_t size = 33;

+ /*
+ * Only generic KASAN uses quarantine, which is required to avoid a
+ * kernel memory corruption this test causes.
+ */
+ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
+
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

--
2.25.1