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
  18#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
  19
  20static noinline void __init copy_user_test(void)
  21{
  22        char *kmem;
  23        char __user *usermem;
  24        size_t size = 10;
  25        int __maybe_unused unused;
  26
  27        kmem = kmalloc(size, GFP_KERNEL);
  28        if (!kmem)
  29                return;
  30
  31        usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
  32                            PROT_READ | PROT_WRITE | PROT_EXEC,
  33                            MAP_ANONYMOUS | MAP_PRIVATE, 0);
  34        if (IS_ERR(usermem)) {
  35                pr_err("Failed to allocate user memory\n");
  36                kfree(kmem);
  37                return;
  38        }
  39
  40        pr_info("out-of-bounds in copy_from_user()\n");
  41        unused = copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
  42
  43        pr_info("out-of-bounds in copy_to_user()\n");
  44        unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
  45
  46        pr_info("out-of-bounds in __copy_from_user()\n");
  47        unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
  48
  49        pr_info("out-of-bounds in __copy_to_user()\n");
  50        unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
  51
  52        pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
  53        unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF);
  54
  55        pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
  56        unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF);
  57
  58        pr_info("out-of-bounds in strncpy_from_user()\n");
  59        unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
  60
  61        vm_munmap((unsigned long)usermem, PAGE_SIZE);
  62        kfree(kmem);
  63}
  64
  65static struct kasan_rcu_info {
  66        int i;
  67        struct rcu_head rcu;
  68} *global_rcu_ptr;
  69
  70static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp)
  71{
  72        struct kasan_rcu_info *fp = container_of(rp,
  73                                                struct kasan_rcu_info, rcu);
  74
  75        kfree(fp);
  76        fp->i = 1;
  77}
  78
  79static noinline void __init kasan_rcu_uaf(void)
  80{
  81        struct kasan_rcu_info *ptr;
  82
  83        pr_info("use-after-free in kasan_rcu_reclaim\n");
  84        ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
  85        if (!ptr) {
  86                pr_err("Allocation failed\n");
  87                return;
  88        }
  89
  90        global_rcu_ptr = rcu_dereference_protected(ptr, NULL);
  91        call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim);
  92}
  93
  94static noinline void __init kasan_workqueue_work(struct work_struct *work)
  95{
  96        kfree(work);
  97}
  98
  99static noinline void __init kasan_workqueue_uaf(void)
 100{
 101        struct workqueue_struct *workqueue;
 102        struct work_struct *work;
 103
 104        workqueue = create_workqueue("kasan_wq_test");
 105        if (!workqueue) {
 106                pr_err("Allocation failed\n");
 107                return;
 108        }
 109        work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
 110        if (!work) {
 111                pr_err("Allocation failed\n");
 112                return;
 113        }
 114
 115        INIT_WORK(work, kasan_workqueue_work);
 116        queue_work(workqueue, work);
 117        destroy_workqueue(workqueue);
 118
 119        pr_info("use-after-free on workqueue\n");
 120        ((volatile struct work_struct *)work)->data;
 121}
 122
 123static int __init test_kasan_module_init(void)
 124{
 125        /*
 126         * Temporarily enable multi-shot mode. Otherwise, KASAN would only
 127         * report the first detected bug and panic the kernel if panic_on_warn
 128         * is enabled.
 129         */
 130        bool multishot = kasan_save_enable_multi_shot();
 131
 132        copy_user_test();
 133        kasan_rcu_uaf();
 134        kasan_workqueue_uaf();
 135
 136        kasan_restore_multi_shot(multishot);
 137        return -EAGAIN;
 138}
 139
 140module_init(test_kasan_module_init);
 141MODULE_LICENSE("GPL");
 142