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 int __init test_kasan_module_init(void) 66 { 67 /* 68 * Temporarily enable multi-shot mode. Otherwise, KASAN would only 69 * report the first detected bug and panic the kernel if panic_on_warn 70 * is enabled. 71 */ 72 bool multishot = kasan_save_enable_multi_shot(); 73 74 copy_user_test(); 75 76 kasan_restore_multi_shot(multishot); 77 return -EAGAIN; 78 } 79 80 module_init(test_kasan_module_init); 81 MODULE_LICENSE("GPL"); 82