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/*
*
* 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/kernel.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
static noinline void __init kmalloc_oob_right(void)
{
char *ptr;
size_t size = 123;
pr_info("out-of-bounds to right\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
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\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
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\n");
ptr = kmalloc_node(size, GFP_KERNEL, 0);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
ptr[size] = 0;
kfree(ptr);
}
static noinline void __init kmalloc_large_oob_right(void)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
pr_info("kmalloc large allocation: out-of-bounds to right\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
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\n");
ptr1 = kmalloc(size1, GFP_KERNEL);
ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
if (!ptr1 || !ptr2) {
pr_err("Allocation failed\n");
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\n");
ptr1 = kmalloc(size1, GFP_KERNEL);
ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
if (!ptr1 || !ptr2) {
pr_err("Allocation failed\n");
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\n");
ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
if (!ptr1 || !ptr2) {
pr_err("Allocation failed\n");
kfree(ptr1);
kfree(ptr2);
return;
}
*ptr1 = *ptr2;
kfree(ptr1);
kfree(ptr2);
}
static noinline void __init kmalloc_oob_in_memset(void)
{
char *ptr;
size_t size = 666;
pr_info("out-of-bounds in memset\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
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\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
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\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
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\n");
ptr1 = kmalloc(size, GFP_KERNEL);
if (!ptr1) {
pr_err("Allocation failed\n");
return;
}
kfree(ptr1);
ptr2 = kmalloc(size, GFP_KERNEL);
if (!ptr2) {
pr_err("Allocation failed\n");
return;
}
ptr1[40] = 'x';
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\n");
return;
}
pr_info("out-of-bounds in kmem_cache_alloc\n");
p = kmem_cache_alloc(cache, GFP_KERNEL);
if (!p) {
pr_err("Allocation failed\n");
kmem_cache_destroy(cache);
return;
}
*p = p[size];
kmem_cache_free(cache, p);
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\n");
*(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\n");
*(volatile char *)p;
}
static int __init kmalloc_tests_init(void)
{
kmalloc_oob_right();
kmalloc_oob_left();
kmalloc_node_oob_right();
kmalloc_large_oob_right();
kmalloc_oob_krealloc_more();
kmalloc_oob_krealloc_less();
kmalloc_oob_16();
kmalloc_oob_in_memset();
kmalloc_uaf();
kmalloc_uaf_memset();
kmalloc_uaf2();
kmem_cache_oob();
kasan_stack_oob();
kasan_global_oob();
return -EAGAIN;
}
module_init(kmalloc_tests_init);
MODULE_LICENSE("GPL");
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