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 "kasan.h" 17 18 static 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 OPTIMIZER_HIDE_VAR(size); 39 40 pr_info("out-of-bounds in copy_from_user()\n"); 41 unused = copy_from_user(kmem, usermem, size + 1); 42 43 pr_info("out-of-bounds in copy_to_user()\n"); 44 unused = copy_to_user(usermem, kmem, size + 1); 45 46 pr_info("out-of-bounds in __copy_from_user()\n"); 47 unused = __copy_from_user(kmem, usermem, size + 1); 48 49 pr_info("out-of-bounds in __copy_to_user()\n"); 50 unused = __copy_to_user(usermem, kmem, size + 1); 51 52 pr_info("out-of-bounds in __copy_from_user_inatomic()\n"); 53 unused = __copy_from_user_inatomic(kmem, usermem, size + 1); 54 55 pr_info("out-of-bounds in __copy_to_user_inatomic()\n"); 56 unused = __copy_to_user_inatomic(usermem, kmem, size + 1); 57 58 pr_info("out-of-bounds in strncpy_from_user()\n"); 59 unused = strncpy_from_user(kmem, usermem, size + 1); 60 61 vm_munmap((unsigned long)usermem, PAGE_SIZE); 62 kfree(kmem); 63 } 64 65 static struct kasan_rcu_info { 66 int i; 67 struct rcu_head rcu; 68 } *global_rcu_ptr; 69 70 static 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 ((volatile struct kasan_rcu_info *)fp)->i; 77 } 78 79 static 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 94 static noinline void __init kasan_workqueue_work(struct work_struct *work) 95 { 96 kfree(work); 97 } 98 99 static 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 } 122 123 static 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 } 139 140 module_init(test_kasan_module_init); 141 MODULE_LICENSE("GPL"); 142