Migrate the copy_user_test to the KUnit framework to verify out-of-bound
detection via KASAN reports in copy_from_user(), copy_to_user() and
their static functions.
This is the last migrated test in kasan_test_module.c, therefore delete
the file.
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
---
Changes v2 -> v3:
- added a long string in usermem for strncpy_from_user. Suggested by Andrey.
---
mm/kasan/Makefile | 2 -
mm/kasan/kasan_test_c.c | 47 +++++++++++++++++++++
mm/kasan/kasan_test_module.c | 81 ------------------------------------
3 files changed, 47 insertions(+), 83 deletions(-)
delete mode 100644 mm/kasan/kasan_test_module.c
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
index b88543e5c0c..1a958e7c8a4 100644
--- a/mm/kasan/Makefile
+++ b/mm/kasan/Makefile
@@ -46,7 +46,6 @@ endif
CFLAGS_kasan_test_c.o := $(CFLAGS_KASAN_TEST)
RUSTFLAGS_kasan_test_rust.o := $(RUSTFLAGS_KASAN)
-CFLAGS_kasan_test_module.o := $(CFLAGS_KASAN_TEST)
obj-y := common.o report.o
obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quarantine.o
@@ -59,4 +58,3 @@ ifdef CONFIG_RUST
endif
obj-$(CONFIG_KASAN_KUNIT_TEST) += kasan_test.o
-obj-$(CONFIG_KASAN_MODULE_TEST) += kasan_test_module.o
diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
index a181e4780d9..382bc64e42d 100644
--- a/mm/kasan/kasan_test_c.c
+++ b/mm/kasan/kasan_test_c.c
@@ -1954,6 +1954,52 @@ static void rust_uaf(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, kasan_test_rust_uaf());
}
+static void copy_user_test_oob(struct kunit *test)
+{
+ char *kmem;
+ char __user *usermem;
+ unsigned long useraddr;
+ size_t size = 128 - KASAN_GRANULE_SIZE;
+ int __maybe_unused unused;
+
+ kmem = kunit_kmalloc(test, size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, kmem);
+
+ useraddr = kunit_vm_mmap(test, NULL, 0, PAGE_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_ANONYMOUS | MAP_PRIVATE, 0);
+ KUNIT_ASSERT_NE_MSG(test, useraddr, 0,
+ "Could not create userspace mm");
+ KUNIT_ASSERT_LT_MSG(test, useraddr, (unsigned long)TASK_SIZE,
+ "Failed to allocate user memory");
+
+ OPTIMIZER_HIDE_VAR(size);
+ usermem = (char __user *)useraddr;
+
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = copy_from_user(kmem, usermem, size + 1));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = copy_to_user(usermem, kmem, size + 1));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = __copy_from_user(kmem, usermem, size + 1));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = __copy_to_user(usermem, kmem, size + 1));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = __copy_from_user_inatomic(kmem, usermem, size + 1));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = __copy_to_user_inatomic(usermem, kmem, size + 1));
+
+ /*
+ * Prepare a long string in usermem to avoid the strncpy_from_user test
+ * bailing out on '\0' before it reaches out-of-bounds.
+ */
+ memset(kmem, 'a', size);
+ KUNIT_EXPECT_EQ(test, copy_to_user(usermem, kmem, size), 0);
+
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ unused = strncpy_from_user(kmem, usermem, size + 1));
+}
+
static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmalloc_oob_right),
KUNIT_CASE(kmalloc_oob_left),
@@ -2028,6 +2074,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(match_all_ptr_tag),
KUNIT_CASE(match_all_mem_tag),
KUNIT_CASE(rust_uaf),
+ KUNIT_CASE(copy_user_test_oob),
{}
};
diff --git a/mm/kasan/kasan_test_module.c b/mm/kasan/kasan_test_module.c
deleted file mode 100644
index 27ec22767e4..00000000000
--- a/mm/kasan/kasan_test_module.c
+++ /dev/null
@@ -1,81 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *
- * Copyright (c) 2014 Samsung Electronics Co., Ltd.
- * Author: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
- */
-
-#define pr_fmt(fmt) "kasan: test: " fmt
-
-#include <linux/mman.h>
-#include <linux/module.h>
-#include <linux/printk.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
-
-#include "kasan.h"
-
-static noinline void __init copy_user_test(void)
-{
- char *kmem;
- char __user *usermem;
- size_t size = 128 - KASAN_GRANULE_SIZE;
- int __maybe_unused unused;
-
- kmem = kmalloc(size, GFP_KERNEL);
- if (!kmem)
- return;
-
- usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
- PROT_READ | PROT_WRITE | PROT_EXEC,
- MAP_ANONYMOUS | MAP_PRIVATE, 0);
- if (IS_ERR(usermem)) {
- pr_err("Failed to allocate user memory\n");
- kfree(kmem);
- return;
- }
-
- OPTIMIZER_HIDE_VAR(size);
-
- pr_info("out-of-bounds in copy_from_user()\n");
- unused = copy_from_user(kmem, usermem, size + 1);
-
- pr_info("out-of-bounds in copy_to_user()\n");
- unused = copy_to_user(usermem, kmem, size + 1);
-
- pr_info("out-of-bounds in __copy_from_user()\n");
- unused = __copy_from_user(kmem, usermem, size + 1);
-
- pr_info("out-of-bounds in __copy_to_user()\n");
- unused = __copy_to_user(usermem, kmem, size + 1);
-
- pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
- unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
-
- pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
- unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
-
- pr_info("out-of-bounds in strncpy_from_user()\n");
- unused = strncpy_from_user(kmem, usermem, size + 1);
-
- vm_munmap((unsigned long)usermem, PAGE_SIZE);
- kfree(kmem);
-}
-
-static int __init kasan_test_module_init(void)
-{
- /*
- * Temporarily enable multi-shot mode. Otherwise, KASAN would only
- * report the first detected bug and panic the kernel if panic_on_warn
- * is enabled.
- */
- bool multishot = kasan_save_enable_multi_shot();
-
- copy_user_test();
-
- kasan_restore_multi_shot(multishot);
- return -EAGAIN;
-}
-
-module_init(kasan_test_module_init);
-MODULE_LICENSE("GPL");
--
2.34.1
