kasan: test: avoid corrupting memory via memset

[linux-2.6-microblaze.git] / lib / test_kasan.c

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index c82a82e..db73bc9 100644 (file)
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -428,64 +428,70 @@ static void kmalloc_uaf_16(struct kunit *test)
        kfree(ptr1);
 }
 
+/*
+ * Note: in the memset tests below, the written range touches both valid and
+ * invalid memory. This makes sure that the instrumentation does not only check
+ * the starting address but the whole range.
+ */
+
 static void kmalloc_oob_memset_2(struct kunit *test)
 {
        char *ptr;
-       size_t size = 8;
+       size_t size = 128 - KASAN_GRANULE_SIZE;
 
        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 7 + OOB_TAG_OFF, 0, 2));
+       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2));
        kfree(ptr);
 }
 
 static void kmalloc_oob_memset_4(struct kunit *test)
 {
        char *ptr;
-       size_t size = 8;
+       size_t size = 128 - KASAN_GRANULE_SIZE;
 
        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 5 + OOB_TAG_OFF, 0, 4));
+       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4));
        kfree(ptr);
 }
 
-
 static void kmalloc_oob_memset_8(struct kunit *test)
 {
        char *ptr;
-       size_t size = 8;
+       size_t size = 128 - KASAN_GRANULE_SIZE;
 
        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 8));
+       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8));
        kfree(ptr);
 }
 
 static void kmalloc_oob_memset_16(struct kunit *test)
 {
        char *ptr;
-       size_t size = 16;
+       size_t size = 128 - KASAN_GRANULE_SIZE;
 
        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 16));
+       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16));
        kfree(ptr);
 }
 
 static void kmalloc_oob_in_memset(struct kunit *test)
 {
        char *ptr;
-       size_t size = 666;
+       size_t size = 128 - KASAN_GRANULE_SIZE;
 
        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + 5 + OOB_TAG_OFF));
+       KUNIT_EXPECT_KASAN_FAIL(test,
+                               memset(ptr, 0, size + KASAN_GRANULE_SIZE));
        kfree(ptr);
 }