[PATCH v11 2/4] kasan: add test for vmalloc

From: Daniel Axtens <dja@axtens.net>
To: kasan-dev@googlegroups.com, linux-mm@kvack.org, x86@kernel.org,
	aryabinin@virtuozzo.com, glider@google.com, luto@kernel.org,
	linux-kernel@vger.kernel.org, mark.rutland@arm.com,
	dvyukov@google.com, christophe.leroy@c-s.fr
Cc: linuxppc-dev@lists.ozlabs.org, gor@linux.ibm.com,
	Daniel Axtens <dja@axtens.net>
Subject: [PATCH v11 2/4] kasan: add test for vmalloc
Date: Thu, 31 Oct 2019 20:39:07 +1100	[thread overview]
Message-ID: <20191031093909.9228-3-dja@axtens.net> (raw)
In-Reply-To: <20191031093909.9228-1-dja@axtens.net>

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

Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>

--

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

