kasan: migrate copy_user_test to kunit

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.

[arnd@arndb.de: export copy_to_kernel_nofault]
  Link: https://lkml.kernel.org/r/20241018151112.3533820-1-arnd@kernel.org
Link: https://lkml.kernel.org/r/20241016131802.3115788-3-snovitoll@gmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yanteng Si <siyanteng@loongson.cn>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Sabyrzhan Tasbolatov 2024-10-16 18:18:01 +05:00 committed by Andrew Morton
parent ae193dd793
commit ca79a00bb9
4 changed files with 48 additions and 83 deletions

View File

@ -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

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@ -1963,6 +1963,52 @@ static void copy_to_kernel_nofault_oob(struct kunit *test)
kfree(ptr);
}
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),
@ -2037,6 +2083,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(match_all_mem_tag),
KUNIT_CASE(copy_to_kernel_nofault_oob),
KUNIT_CASE(rust_uaf),
KUNIT_CASE(copy_user_test_oob),
{}
};

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@ -1,81 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* Author: Andrey Ryabinin <a.ryabinin@samsung.com>
*/
#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");

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@ -82,6 +82,7 @@ Efault:
pagefault_enable();
return -EFAULT;
}
EXPORT_SYMBOL_GPL(copy_to_kernel_nofault);
long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
{