// 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: %s " fmt, __func__ #include <linux/mman.h> #include <linux/module.h> #include <linux/printk.h> #include <linux/slab.h> #include <linux/uaccess.h> #include "../mm/kasan/kasan.h" #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) static noinline void __init copy_user_test(void) { char *kmem; char __user *usermem; size_t size = 10; 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; } pr_info("out-of-bounds in copy_from_user()\n"); unused = copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); pr_info("out-of-bounds in copy_to_user()\n"); unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF); pr_info("out-of-bounds in __copy_from_user()\n"); unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); pr_info("out-of-bounds in __copy_to_user()\n"); unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF); pr_info("out-of-bounds in __copy_from_user_inatomic()\n"); unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF); pr_info("out-of-bounds in __copy_to_user_inatomic()\n"); unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF); pr_info("out-of-bounds in strncpy_from_user()\n"); unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); vm_munmap((unsigned long)usermem, PAGE_SIZE); kfree(kmem); } static struct kasan_rcu_info { int i; struct rcu_head rcu; } *global_rcu_ptr; static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp) { struct kasan_rcu_info *fp = container_of(rp, struct kasan_rcu_info, rcu); kfree(fp); fp->i = 1; } static noinline void __init kasan_rcu_uaf(void) { struct kasan_rcu_info *ptr; pr_info("use-after-free in kasan_rcu_reclaim\n"); ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL); if (!ptr) { pr_err("Allocation failed\n"); return; } global_rcu_ptr = rcu_dereference_protected(ptr, NULL); call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim); } static noinline void __init kasan_workqueue_work(struct work_struct *work) { kfree(work); } static noinline void __init kasan_workqueue_uaf(void) { struct workqueue_struct *workqueue; struct work_struct *work; workqueue = create_workqueue("kasan_wq_test"); if (!workqueue) { pr_err("Allocation failed\n"); return; } work = kmalloc(sizeof(struct work_struct), GFP_KERNEL); if (!work) { pr_err("Allocation failed\n"); return; } INIT_WORK(work, kasan_workqueue_work); queue_work(workqueue, work); destroy_workqueue(workqueue); pr_info("use-after-free on workqueue\n"); ((volatile struct work_struct *)work)->data; } static int __init test_kasan_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_rcu_uaf(); kasan_workqueue_uaf(); kasan_restore_multi_shot(multishot); return -EAGAIN; } module_init(test_kasan_module_init); MODULE_LICENSE("GPL");