linux/security/integrity/iint.c
Paul Gortmaker 876979c930 security: audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.

The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.

Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace as needed.

Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-12-12 14:58:51 -08:00

239 lines
5.4 KiB
C

/*
* Copyright (C) 2008 IBM Corporation
*
* Authors:
* Mimi Zohar <zohar@us.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
* File: integrity_iint.c
* - implements the integrity hooks: integrity_inode_alloc,
* integrity_inode_free
* - cache integrity information associated with an inode
* using a rbtree tree.
*/
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/rbtree.h>
#include <linux/file.h>
#include <linux/uaccess.h>
#include <linux/security.h>
#include <linux/lsm_hooks.h>
#include "integrity.h"
static struct rb_root integrity_iint_tree = RB_ROOT;
static DEFINE_RWLOCK(integrity_iint_lock);
static struct kmem_cache *iint_cache __read_mostly;
struct dentry *integrity_dir;
/*
* __integrity_iint_find - return the iint associated with an inode
*/
static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
{
struct integrity_iint_cache *iint;
struct rb_node *n = integrity_iint_tree.rb_node;
while (n) {
iint = rb_entry(n, struct integrity_iint_cache, rb_node);
if (inode < iint->inode)
n = n->rb_left;
else if (inode > iint->inode)
n = n->rb_right;
else
break;
}
if (!n)
return NULL;
return iint;
}
/*
* integrity_iint_find - return the iint associated with an inode
*/
struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
{
struct integrity_iint_cache *iint;
if (!IS_IMA(inode))
return NULL;
read_lock(&integrity_iint_lock);
iint = __integrity_iint_find(inode);
read_unlock(&integrity_iint_lock);
return iint;
}
static void iint_free(struct integrity_iint_cache *iint)
{
kfree(iint->ima_hash);
iint->ima_hash = NULL;
iint->version = 0;
iint->flags = 0UL;
iint->atomic_flags = 0UL;
iint->ima_file_status = INTEGRITY_UNKNOWN;
iint->ima_mmap_status = INTEGRITY_UNKNOWN;
iint->ima_bprm_status = INTEGRITY_UNKNOWN;
iint->ima_read_status = INTEGRITY_UNKNOWN;
iint->ima_creds_status = INTEGRITY_UNKNOWN;
iint->evm_status = INTEGRITY_UNKNOWN;
iint->measured_pcrs = 0;
kmem_cache_free(iint_cache, iint);
}
/**
* integrity_inode_get - find or allocate an iint associated with an inode
* @inode: pointer to the inode
* @return: allocated iint
*
* Caller must lock i_mutex
*/
struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
{
struct rb_node **p;
struct rb_node *node, *parent = NULL;
struct integrity_iint_cache *iint, *test_iint;
iint = integrity_iint_find(inode);
if (iint)
return iint;
iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
if (!iint)
return NULL;
write_lock(&integrity_iint_lock);
p = &integrity_iint_tree.rb_node;
while (*p) {
parent = *p;
test_iint = rb_entry(parent, struct integrity_iint_cache,
rb_node);
if (inode < test_iint->inode)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
iint->inode = inode;
node = &iint->rb_node;
inode->i_flags |= S_IMA;
rb_link_node(node, parent, p);
rb_insert_color(node, &integrity_iint_tree);
write_unlock(&integrity_iint_lock);
return iint;
}
/**
* integrity_inode_free - called on security_inode_free
* @inode: pointer to the inode
*
* Free the integrity information(iint) associated with an inode.
*/
void integrity_inode_free(struct inode *inode)
{
struct integrity_iint_cache *iint;
if (!IS_IMA(inode))
return;
write_lock(&integrity_iint_lock);
iint = __integrity_iint_find(inode);
rb_erase(&iint->rb_node, &integrity_iint_tree);
write_unlock(&integrity_iint_lock);
iint_free(iint);
}
static void init_once(void *foo)
{
struct integrity_iint_cache *iint = foo;
memset(iint, 0, sizeof(*iint));
iint->ima_file_status = INTEGRITY_UNKNOWN;
iint->ima_mmap_status = INTEGRITY_UNKNOWN;
iint->ima_bprm_status = INTEGRITY_UNKNOWN;
iint->ima_read_status = INTEGRITY_UNKNOWN;
iint->ima_creds_status = INTEGRITY_UNKNOWN;
iint->evm_status = INTEGRITY_UNKNOWN;
mutex_init(&iint->mutex);
}
static int __init integrity_iintcache_init(void)
{
iint_cache =
kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
0, SLAB_PANIC, init_once);
return 0;
}
DEFINE_LSM(integrity) = {
.name = "integrity",
.init = integrity_iintcache_init,
};
/*
* integrity_kernel_read - read data from the file
*
* This is a function for reading file content instead of kernel_read().
* It does not perform locking checks to ensure it cannot be blocked.
* It does not perform security checks because it is irrelevant for IMA.
*
*/
int integrity_kernel_read(struct file *file, loff_t offset,
void *addr, unsigned long count)
{
mm_segment_t old_fs;
char __user *buf = (char __user *)addr;
ssize_t ret;
if (!(file->f_mode & FMODE_READ))
return -EBADF;
old_fs = get_fs();
set_fs(get_ds());
ret = __vfs_read(file, buf, count, &offset);
set_fs(old_fs);
return ret;
}
/*
* integrity_load_keys - load integrity keys hook
*
* Hooks is called from init/main.c:kernel_init_freeable()
* when rootfs is ready
*/
void __init integrity_load_keys(void)
{
ima_load_x509();
evm_load_x509();
}
static int __init integrity_fs_init(void)
{
integrity_dir = securityfs_create_dir("integrity", NULL);
if (IS_ERR(integrity_dir)) {
int ret = PTR_ERR(integrity_dir);
if (ret != -ENODEV)
pr_err("Unable to create integrity sysfs dir: %d\n",
ret);
integrity_dir = NULL;
return ret;
}
return 0;
}
late_initcall(integrity_fs_init)