mirror of
https://github.com/torvalds/linux.git
synced 2025-10-31 16:48:26 +02:00
d73dad4eb5
Intentional overflows, as performed by the KASAN tests, are detected at compile time[1] (instead of only at run-time) with the addition of __alloc_size. Fix this by forcing the compiler into not being able to trust the size used following the kmalloc()s. [1] https://lore.kernel.org/lkml/20211005184717.65c6d8eb39350395e387b71f@linux-foundation.org Link: https://lkml.kernel.org/r/20211006181544.1670992-1-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
141 lines
3.3 KiB
C
141 lines
3.3 KiB
C
// 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"
|
|
|
|
static noinline void __init copy_user_test(void)
|
|
{
|
|
char *kmem;
|
|
char __user *usermem;
|
|
size_t size = 128 - KASAN_GRANULE_SIZE;
|
|
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;
|
|
}
|
|
|
|
OPTIMIZER_HIDE_VAR(size);
|
|
|
|
pr_info("out-of-bounds in copy_from_user()\n");
|
|
unused = copy_from_user(kmem, usermem, size + 1);
|
|
|
|
pr_info("out-of-bounds in copy_to_user()\n");
|
|
unused = copy_to_user(usermem, kmem, size + 1);
|
|
|
|
pr_info("out-of-bounds in __copy_from_user()\n");
|
|
unused = __copy_from_user(kmem, usermem, size + 1);
|
|
|
|
pr_info("out-of-bounds in __copy_to_user()\n");
|
|
unused = __copy_to_user(usermem, kmem, size + 1);
|
|
|
|
pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
|
|
unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
|
|
|
|
pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
|
|
unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
|
|
|
|
pr_info("out-of-bounds in strncpy_from_user()\n");
|
|
unused = strncpy_from_user(kmem, usermem, size + 1);
|
|
|
|
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);
|
|
((volatile struct kasan_rcu_info *)fp)->i;
|
|
}
|
|
|
|
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");
|