LXR linux/lib/test_kasan

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   5 * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
   6 */
   7
   8#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
   9
  10#include <linux/mman.h>
  11#include <linux/module.h>
  12#include <linux/printk.h>
  13#include <linux/slab.h>
  14#include <linux/uaccess.h>
  15
  16#include "../mm/kasan/kasan.h"
  17
  18static noinline void __init copy_user_test(void)
  19{
  20        char *kmem;
  21        char __user *usermem;
  22        size_t size = 128 - KASAN_GRANULE_SIZE;
  23        int __maybe_unused unused;
  24
  25        kmem = kmalloc(size, GFP_KERNEL);
  26        if (!kmem)
  27                return;
  28
  29        usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
  30                            PROT_READ | PROT_WRITE | PROT_EXEC,
  31                            MAP_ANONYMOUS | MAP_PRIVATE, 0);
  32        if (IS_ERR(usermem)) {
  33                pr_err("Failed to allocate user memory\n");
  34                kfree(kmem);
  35                return;
  36        }
  37
  38        pr_info("out-of-bounds in copy_from_user()\n");
  39        unused = copy_from_user(kmem, usermem, size + 1);
  40
  41        pr_info("out-of-bounds in copy_to_user()\n");
  42        unused = copy_to_user(usermem, kmem, size + 1);
  43
  44        pr_info("out-of-bounds in __copy_from_user()\n");
  45        unused = __copy_from_user(kmem, usermem, size + 1);
  46
  47        pr_info("out-of-bounds in __copy_to_user()\n");
  48        unused = __copy_to_user(usermem, kmem, size + 1);
  49
  50        pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
  51        unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
  52
  53        pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
  54        unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
  55
  56        pr_info("out-of-bounds in strncpy_from_user()\n");
  57        unused = strncpy_from_user(kmem, usermem, size + 1);
  58
  59        vm_munmap((unsigned long)usermem, PAGE_SIZE);
  60        kfree(kmem);
  61}
  62
  63static struct kasan_rcu_info {
  64        int i;
  65        struct rcu_head rcu;
  66} *global_rcu_ptr;
  67
  68static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp)
  69{
  70        struct kasan_rcu_info *fp = container_of(rp,
  71                                                struct kasan_rcu_info, rcu);
  72
  73        kfree(fp);
  74        ((volatile struct kasan_rcu_info *)fp)->i;
  75}
  76
  77static noinline void __init kasan_rcu_uaf(void)
  78{
  79        struct kasan_rcu_info *ptr;
  80
  81        pr_info("use-after-free in kasan_rcu_reclaim\n");
  82        ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
  83        if (!ptr) {
  84                pr_err("Allocation failed\n");
  85                return;
  86        }
  87
  88        global_rcu_ptr = rcu_dereference_protected(ptr, NULL);
  89        call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim);
  90}
  91
  92static noinline void __init kasan_workqueue_work(struct work_struct *work)
  93{
  94        kfree(work);
  95}
  96
  97static noinline void __init kasan_workqueue_uaf(void)
  98{
  99        struct workqueue_struct *workqueue;
 100        struct work_struct *work;
 101
 102        workqueue = create_workqueue("kasan_wq_test");
 103        if (!workqueue) {
 104                pr_err("Allocation failed\n");
 105                return;
 106        }
 107        work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
 108        if (!work) {
 109                pr_err("Allocation failed\n");
 110                return;
 111        }
 112
 113        INIT_WORK(work, kasan_workqueue_work);
 114        queue_work(workqueue, work);
 115        destroy_workqueue(workqueue);
 116
 117        pr_info("use-after-free on workqueue\n");
 118        ((volatile struct work_struct *)work)->data;
 119}
 120
 121static int __init test_kasan_module_init(void)
 122{
 123        /*
 124         * Temporarily enable multi-shot mode. Otherwise, KASAN would only
 125         * report the first detected bug and panic the kernel if panic_on_warn
 126         * is enabled.
 127         */
 128        bool multishot = kasan_save_enable_multi_shot();
 129
 130        copy_user_test();
 131        kasan_rcu_uaf();
 132        kasan_workqueue_uaf();
 133
 134        kasan_restore_multi_shot(multishot);
 135        return -EAGAIN;
 136}
 137
 138module_init(test_kasan_module_init);
 139MODULE_LICENSE("GPL");
 140