/*
   *
   * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  
  #define pr_fmt(fmt) "kasan test: %s " fmt, __func__

  #include <linux/delay.h>

  #include <linux/kernel.h>

  #include <linux/mman.h>
  #include <linux/mm.h>

  #include <linux/printk.h>
  #include <linux/slab.h>
  #include <linux/string.h>

  #include <linux/uaccess.h>

  #include <linux/module.h>

  #include <linux/kasan.h>

  /*
   * Note: test functions are marked noinline so that their names appear in
   * reports.
   */

  static noinline void __init kmalloc_oob_right(void)
  {
  	char *ptr;
  	size_t size = 123;
  
  	pr_info("out-of-bounds to right
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	ptr[size] = 'x';
  	kfree(ptr);
  }
  
  static noinline void __init kmalloc_oob_left(void)
  {
  	char *ptr;
  	size_t size = 15;
  
  	pr_info("out-of-bounds to left
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	*ptr = *(ptr - 1);
  	kfree(ptr);
  }
  
  static noinline void __init kmalloc_node_oob_right(void)
  {
  	char *ptr;
  	size_t size = 4096;
  
  	pr_info("kmalloc_node(): out-of-bounds to right
  ");
  	ptr = kmalloc_node(size, GFP_KERNEL, 0);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	ptr[size] = 0;
  	kfree(ptr);
  }

  #ifdef CONFIG_SLUB
  static noinline void __init kmalloc_pagealloc_oob_right(void)

  {
  	char *ptr;
  	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

  	/* Allocate a chunk that does not fit into a SLUB cache to trigger
  	 * the page allocator fallback.
  	 */
  	pr_info("kmalloc pagealloc allocation: out-of-bounds to right
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	ptr[size] = 0;
  	kfree(ptr);
  }

  
  static noinline void __init kmalloc_pagealloc_uaf(void)
  {
  	char *ptr;
  	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
  
  	pr_info("kmalloc pagealloc allocation: use-after-free
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	kfree(ptr);
  	ptr[0] = 0;
  }
  
  static noinline void __init kmalloc_pagealloc_invalid_free(void)
  {
  	char *ptr;
  	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
  
  	pr_info("kmalloc pagealloc allocation: invalid-free
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	kfree(ptr + 1);
  }

  #endif
  
  static noinline void __init kmalloc_large_oob_right(void)
  {
  	char *ptr;
  	size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
  	/* Allocate a chunk that is large enough, but still fits into a slab
  	 * and does not trigger the page allocator fallback in SLUB.
  	 */

  	pr_info("kmalloc large allocation: out-of-bounds to right
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	ptr[size] = 0;
  	kfree(ptr);
  }
  
  static noinline void __init kmalloc_oob_krealloc_more(void)
  {
  	char *ptr1, *ptr2;
  	size_t size1 = 17;
  	size_t size2 = 19;
  
  	pr_info("out-of-bounds after krealloc more
  ");
  	ptr1 = kmalloc(size1, GFP_KERNEL);
  	ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
  	if (!ptr1 || !ptr2) {
  		pr_err("Allocation failed
  ");
  		kfree(ptr1);
  		return;
  	}
  
  	ptr2[size2] = 'x';
  	kfree(ptr2);
  }
  
  static noinline void __init kmalloc_oob_krealloc_less(void)
  {
  	char *ptr1, *ptr2;
  	size_t size1 = 17;
  	size_t size2 = 15;
  
  	pr_info("out-of-bounds after krealloc less
  ");
  	ptr1 = kmalloc(size1, GFP_KERNEL);
  	ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
  	if (!ptr1 || !ptr2) {
  		pr_err("Allocation failed
  ");
  		kfree(ptr1);
  		return;
  	}

  	ptr2[size2] = 'x';

  	kfree(ptr2);
  }
  
  static noinline void __init kmalloc_oob_16(void)
  {
  	struct {
  		u64 words[2];
  	} *ptr1, *ptr2;
  
  	pr_info("kmalloc out-of-bounds for 16-bytes access
  ");
  	ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
  	ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
  	if (!ptr1 || !ptr2) {
  		pr_err("Allocation failed
  ");
  		kfree(ptr1);
  		kfree(ptr2);
  		return;
  	}
  	*ptr1 = *ptr2;
  	kfree(ptr1);
  	kfree(ptr2);
  }

  static noinline void __init kmalloc_oob_memset_2(void)
  {
  	char *ptr;
  	size_t size = 8;
  
  	pr_info("out-of-bounds in memset2
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	memset(ptr+7, 0, 2);
  	kfree(ptr);
  }
  
  static noinline void __init kmalloc_oob_memset_4(void)
  {
  	char *ptr;
  	size_t size = 8;
  
  	pr_info("out-of-bounds in memset4
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	memset(ptr+5, 0, 4);
  	kfree(ptr);
  }
  
  
  static noinline void __init kmalloc_oob_memset_8(void)
  {
  	char *ptr;
  	size_t size = 8;
  
  	pr_info("out-of-bounds in memset8
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	memset(ptr+1, 0, 8);
  	kfree(ptr);
  }
  
  static noinline void __init kmalloc_oob_memset_16(void)
  {
  	char *ptr;
  	size_t size = 16;
  
  	pr_info("out-of-bounds in memset16
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	memset(ptr+1, 0, 16);
  	kfree(ptr);
  }

  static noinline void __init kmalloc_oob_in_memset(void)
  {
  	char *ptr;
  	size_t size = 666;
  
  	pr_info("out-of-bounds in memset
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	memset(ptr, 0, size+5);
  	kfree(ptr);
  }
  
  static noinline void __init kmalloc_uaf(void)
  {
  	char *ptr;
  	size_t size = 10;
  
  	pr_info("use-after-free
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	kfree(ptr);
  	*(ptr + 8) = 'x';
  }
  
  static noinline void __init kmalloc_uaf_memset(void)
  {
  	char *ptr;
  	size_t size = 33;
  
  	pr_info("use-after-free in memset
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	kfree(ptr);
  	memset(ptr, 0, size);
  }
  
  static noinline void __init kmalloc_uaf2(void)
  {
  	char *ptr1, *ptr2;
  	size_t size = 43;
  
  	pr_info("use-after-free after another kmalloc
  ");
  	ptr1 = kmalloc(size, GFP_KERNEL);
  	if (!ptr1) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	kfree(ptr1);
  	ptr2 = kmalloc(size, GFP_KERNEL);
  	if (!ptr2) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  
  	ptr1[40] = 'x';

  	if (ptr1 == ptr2)
  		pr_err("Could not detect use-after-free: ptr1 == ptr2
  ");

  	kfree(ptr2);
  }
  
  static noinline void __init kmem_cache_oob(void)
  {
  	char *p;
  	size_t size = 200;
  	struct kmem_cache *cache = kmem_cache_create("test_cache",
  						size, 0,
  						0, NULL);
  	if (!cache) {
  		pr_err("Cache allocation failed
  ");
  		return;
  	}
  	pr_info("out-of-bounds in kmem_cache_alloc
  ");
  	p = kmem_cache_alloc(cache, GFP_KERNEL);
  	if (!p) {
  		pr_err("Allocation failed
  ");
  		kmem_cache_destroy(cache);
  		return;
  	}
  
  	*p = p[size];
  	kmem_cache_free(cache, p);
  	kmem_cache_destroy(cache);
  }

  static noinline void __init memcg_accounted_kmem_cache(void)
  {
  	int i;
  	char *p;
  	size_t size = 200;
  	struct kmem_cache *cache;
  
  	cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
  	if (!cache) {
  		pr_err("Cache allocation failed
  ");
  		return;
  	}
  
  	pr_info("allocate memcg accounted object
  ");
  	/*
  	 * Several allocations with a delay to allow for lazy per memcg kmem
  	 * cache creation.
  	 */
  	for (i = 0; i < 5; i++) {
  		p = kmem_cache_alloc(cache, GFP_KERNEL);

  		if (!p)

  			goto free_cache;

  		kmem_cache_free(cache, p);
  		msleep(100);
  	}
  
  free_cache:
  	kmem_cache_destroy(cache);
  }

  static char global_array[10];
  
  static noinline void __init kasan_global_oob(void)
  {
  	volatile int i = 3;
  	char *p = &global_array[ARRAY_SIZE(global_array) + i];
  
  	pr_info("out-of-bounds global variable
  ");
  	*(volatile char *)p;
  }
  
  static noinline void __init kasan_stack_oob(void)
  {
  	char stack_array[10];
  	volatile int i = 0;
  	char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
  
  	pr_info("out-of-bounds on stack
  ");
  	*(volatile char *)p;
  }

  static noinline void __init ksize_unpoisons_memory(void)
  {
  	char *ptr;

  	size_t size = 123, real_size;

  
  	pr_info("ksize() unpoisons the whole allocated chunk
  ");
  	ptr = kmalloc(size, GFP_KERNEL);
  	if (!ptr) {
  		pr_err("Allocation failed
  ");
  		return;
  	}
  	real_size = ksize(ptr);
  	/* This access doesn't trigger an error. */
  	ptr[size] = 'x';
  	/* This one does. */
  	ptr[real_size] = 'y';
  	kfree(ptr);
  }

  static noinline void __init copy_user_test(void)
  {
  	char *kmem;
  	char __user *usermem;
  	size_t size = 10;
  	int 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
  ");
  		kfree(kmem);
  		return;
  	}
  
  	pr_info("out-of-bounds in copy_from_user()
  ");
  	unused = copy_from_user(kmem, usermem, size + 1);
  
  	pr_info("out-of-bounds in copy_to_user()
  ");
  	unused = copy_to_user(usermem, kmem, size + 1);
  
  	pr_info("out-of-bounds in __copy_from_user()
  ");
  	unused = __copy_from_user(kmem, usermem, size + 1);
  
  	pr_info("out-of-bounds in __copy_to_user()
  ");
  	unused = __copy_to_user(usermem, kmem, size + 1);
  
  	pr_info("out-of-bounds in __copy_from_user_inatomic()
  ");
  	unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
  
  	pr_info("out-of-bounds in __copy_to_user_inatomic()
  ");
  	unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
  
  	pr_info("out-of-bounds in strncpy_from_user()
  ");
  	unused = strncpy_from_user(kmem, usermem, size + 1);
  
  	vm_munmap((unsigned long)usermem, PAGE_SIZE);
  	kfree(kmem);
  }

  static noinline void __init use_after_scope_test(void)
  {
  	volatile char *volatile p;
  
  	pr_info("use-after-scope on int
  ");
  	{
  		int local = 0;
  
  		p = (char *)&local;
  	}
  	p[0] = 1;
  	p[3] = 1;
  
  	pr_info("use-after-scope on array
  ");
  	{
  		char local[1024] = {0};
  
  		p = local;
  	}
  	p[0] = 1;
  	p[1023] = 1;
  }

  static noinline void __init kasan_alloca_oob_left(void)
  {
  	volatile int i = 10;
  	char alloca_array[i];
  	char *p = alloca_array - 1;
  
  	pr_info("out-of-bounds to left on alloca
  ");
  	*(volatile char *)p;
  }
  
  static noinline void __init kasan_alloca_oob_right(void)
  {
  	volatile int i = 10;
  	char alloca_array[i];
  	char *p = alloca_array + i;
  
  	pr_info("out-of-bounds to right on alloca
  ");
  	*(volatile char *)p;
  }

  static noinline void __init kmem_cache_double_free(void)
  {
  	char *p;
  	size_t size = 200;
  	struct kmem_cache *cache;
  
  	cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
  	if (!cache) {
  		pr_err("Cache allocation failed
  ");
  		return;
  	}
  	pr_info("double-free on heap object
  ");
  	p = kmem_cache_alloc(cache, GFP_KERNEL);
  	if (!p) {
  		pr_err("Allocation failed
  ");
  		kmem_cache_destroy(cache);
  		return;
  	}
  
  	kmem_cache_free(cache, p);
  	kmem_cache_free(cache, p);
  	kmem_cache_destroy(cache);
  }
  
  static noinline void __init kmem_cache_invalid_free(void)
  {
  	char *p;
  	size_t size = 200;
  	struct kmem_cache *cache;
  
  	cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
  				  NULL);
  	if (!cache) {
  		pr_err("Cache allocation failed
  ");
  		return;
  	}
  	pr_info("invalid-free of heap object
  ");
  	p = kmem_cache_alloc(cache, GFP_KERNEL);
  	if (!p) {
  		pr_err("Allocation failed
  ");
  		kmem_cache_destroy(cache);
  		return;
  	}

  	/* Trigger invalid free, the object doesn't get freed */

  	kmem_cache_free(cache, p + 1);

  
  	/*
  	 * Properly free the object to prevent the "Objects remaining in
  	 * test_cache on __kmem_cache_shutdown" BUG failure.
  	 */
  	kmem_cache_free(cache, p);

  	kmem_cache_destroy(cache);
  }

  static int __init kmalloc_tests_init(void)
  {

  	/*
  	 * Temporarily enable multi-shot mode. Otherwise, we'd only get a
  	 * report for the first case.
  	 */
  	bool multishot = kasan_save_enable_multi_shot();

  	kmalloc_oob_right();
  	kmalloc_oob_left();
  	kmalloc_node_oob_right();

  #ifdef CONFIG_SLUB
  	kmalloc_pagealloc_oob_right();

  	kmalloc_pagealloc_uaf();
  	kmalloc_pagealloc_invalid_free();

  #endif

  	kmalloc_large_oob_right();

  	kmalloc_oob_krealloc_more();
  	kmalloc_oob_krealloc_less();
  	kmalloc_oob_16();
  	kmalloc_oob_in_memset();

  	kmalloc_oob_memset_2();
  	kmalloc_oob_memset_4();
  	kmalloc_oob_memset_8();
  	kmalloc_oob_memset_16();

  	kmalloc_uaf();
  	kmalloc_uaf_memset();
  	kmalloc_uaf2();
  	kmem_cache_oob();

  	memcg_accounted_kmem_cache();

  	kasan_stack_oob();
  	kasan_global_oob();

  	kasan_alloca_oob_left();
  	kasan_alloca_oob_right();

  	ksize_unpoisons_memory();

  	copy_user_test();

  	use_after_scope_test();

  	kmem_cache_double_free();
  	kmem_cache_invalid_free();

  
  	kasan_restore_multi_shot(multishot);

  	return -EAGAIN;
  }
  
  module_init(kmalloc_tests_init);
  MODULE_LICENSE("GPL");