mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 13:26:41 +07:00
3e2a4c183a
To help avoid an architecture failing to correctly check kernel/user
boundaries when handling copy_to_user, copy_from_user, put_user, or
get_user, perform some simple tests and fail to load if any of them
behave unexpectedly.
Specifically, this is to make sure there is a way to notice if things
like what was fixed in commit 8404663f81 ("ARM: 7527/1: uaccess:
explicitly check __user pointer when !CPU_USE_DOMAINS") ever regresses
again, for any architecture.
Additionally, adds new "user" selftest target, which loads this module.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
111 lines
3.1 KiB
C
111 lines
3.1 KiB
C
/*
|
|
* Kernel module for testing copy_to/from_user infrastructure.
|
|
*
|
|
* Copyright 2013 Google Inc. All Rights Reserved
|
|
*
|
|
* Authors:
|
|
* Kees Cook <keescook@chromium.org>
|
|
*
|
|
* This software is licensed under the terms of the GNU General Public
|
|
* License version 2, as published by the Free Software Foundation, and
|
|
* may be copied, distributed, and modified under those terms.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/mman.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
#define test(condition, msg) \
|
|
({ \
|
|
int cond = (condition); \
|
|
if (cond) \
|
|
pr_warn("%s\n", msg); \
|
|
cond; \
|
|
})
|
|
|
|
static int __init test_user_copy_init(void)
|
|
{
|
|
int ret = 0;
|
|
char *kmem;
|
|
char __user *usermem;
|
|
char *bad_usermem;
|
|
unsigned long user_addr;
|
|
unsigned long value = 0x5A;
|
|
|
|
kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
|
|
if (!kmem)
|
|
return -ENOMEM;
|
|
|
|
user_addr = vm_mmap(NULL, 0, PAGE_SIZE * 2,
|
|
PROT_READ | PROT_WRITE | PROT_EXEC,
|
|
MAP_ANONYMOUS | MAP_PRIVATE, 0);
|
|
if (user_addr >= (unsigned long)(TASK_SIZE)) {
|
|
pr_warn("Failed to allocate user memory\n");
|
|
kfree(kmem);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
usermem = (char __user *)user_addr;
|
|
bad_usermem = (char *)user_addr;
|
|
|
|
/* Legitimate usage: none of these should fail. */
|
|
ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE),
|
|
"legitimate copy_from_user failed");
|
|
ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE),
|
|
"legitimate copy_to_user failed");
|
|
ret |= test(get_user(value, (unsigned long __user *)usermem),
|
|
"legitimate get_user failed");
|
|
ret |= test(put_user(value, (unsigned long __user *)usermem),
|
|
"legitimate put_user failed");
|
|
|
|
/* Invalid usage: none of these should succeed. */
|
|
ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
|
|
PAGE_SIZE),
|
|
"illegal all-kernel copy_from_user passed");
|
|
ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem,
|
|
PAGE_SIZE),
|
|
"illegal reversed copy_from_user passed");
|
|
ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
|
|
PAGE_SIZE),
|
|
"illegal all-kernel copy_to_user passed");
|
|
ret |= test(!copy_to_user((char __user *)kmem, bad_usermem,
|
|
PAGE_SIZE),
|
|
"illegal reversed copy_to_user passed");
|
|
ret |= test(!get_user(value, (unsigned long __user *)kmem),
|
|
"illegal get_user passed");
|
|
ret |= test(!put_user(value, (unsigned long __user *)kmem),
|
|
"illegal put_user passed");
|
|
|
|
vm_munmap(user_addr, PAGE_SIZE * 2);
|
|
kfree(kmem);
|
|
|
|
if (ret == 0) {
|
|
pr_info("tests passed.\n");
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
module_init(test_user_copy_init);
|
|
|
|
static void __exit test_user_copy_exit(void)
|
|
{
|
|
pr_info("unloaded.\n");
|
|
}
|
|
|
|
module_exit(test_user_copy_exit);
|
|
|
|
MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
|
|
MODULE_LICENSE("GPL");
|