Loading...
1/*
2 * Copyright (C) 2008 IBM Corporation
3 *
4 * Authors:
5 * Mimi Zohar <zohar@us.ibm.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation, version 2 of the
10 * License.
11 *
12 * File: integrity_iint.c
13 * - implements the integrity hooks: integrity_inode_alloc,
14 * integrity_inode_free
15 * - cache integrity information associated with an inode
16 * using a rbtree tree.
17 */
18#include <linux/slab.h>
19#include <linux/module.h>
20#include <linux/spinlock.h>
21#include <linux/rbtree.h>
22#include "integrity.h"
23
24static struct rb_root integrity_iint_tree = RB_ROOT;
25static DEFINE_SPINLOCK(integrity_iint_lock);
26static struct kmem_cache *iint_cache __read_mostly;
27
28int iint_initialized;
29
30/*
31 * __integrity_iint_find - return the iint associated with an inode
32 */
33static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
34{
35 struct integrity_iint_cache *iint;
36 struct rb_node *n = integrity_iint_tree.rb_node;
37
38 assert_spin_locked(&integrity_iint_lock);
39
40 while (n) {
41 iint = rb_entry(n, struct integrity_iint_cache, rb_node);
42
43 if (inode < iint->inode)
44 n = n->rb_left;
45 else if (inode > iint->inode)
46 n = n->rb_right;
47 else
48 break;
49 }
50 if (!n)
51 return NULL;
52
53 return iint;
54}
55
56/*
57 * integrity_iint_find - return the iint associated with an inode
58 */
59struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
60{
61 struct integrity_iint_cache *iint;
62
63 if (!IS_IMA(inode))
64 return NULL;
65
66 spin_lock(&integrity_iint_lock);
67 iint = __integrity_iint_find(inode);
68 spin_unlock(&integrity_iint_lock);
69
70 return iint;
71}
72
73static void iint_free(struct integrity_iint_cache *iint)
74{
75 iint->version = 0;
76 iint->flags = 0UL;
77 iint->evm_status = INTEGRITY_UNKNOWN;
78 kmem_cache_free(iint_cache, iint);
79}
80
81/**
82 * integrity_inode_alloc - allocate an iint associated with an inode
83 * @inode: pointer to the inode
84 */
85int integrity_inode_alloc(struct inode *inode)
86{
87 struct rb_node **p;
88 struct rb_node *new_node, *parent = NULL;
89 struct integrity_iint_cache *new_iint, *test_iint;
90 int rc;
91
92 new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
93 if (!new_iint)
94 return -ENOMEM;
95
96 new_iint->inode = inode;
97 new_node = &new_iint->rb_node;
98
99 mutex_lock(&inode->i_mutex); /* i_flags */
100 spin_lock(&integrity_iint_lock);
101
102 p = &integrity_iint_tree.rb_node;
103 while (*p) {
104 parent = *p;
105 test_iint = rb_entry(parent, struct integrity_iint_cache,
106 rb_node);
107 rc = -EEXIST;
108 if (inode < test_iint->inode)
109 p = &(*p)->rb_left;
110 else if (inode > test_iint->inode)
111 p = &(*p)->rb_right;
112 else
113 goto out_err;
114 }
115
116 inode->i_flags |= S_IMA;
117 rb_link_node(new_node, parent, p);
118 rb_insert_color(new_node, &integrity_iint_tree);
119
120 spin_unlock(&integrity_iint_lock);
121 mutex_unlock(&inode->i_mutex); /* i_flags */
122
123 return 0;
124out_err:
125 spin_unlock(&integrity_iint_lock);
126 mutex_unlock(&inode->i_mutex); /* i_flags */
127 iint_free(new_iint);
128
129 return rc;
130}
131
132/**
133 * integrity_inode_free - called on security_inode_free
134 * @inode: pointer to the inode
135 *
136 * Free the integrity information(iint) associated with an inode.
137 */
138void integrity_inode_free(struct inode *inode)
139{
140 struct integrity_iint_cache *iint;
141
142 if (!IS_IMA(inode))
143 return;
144
145 spin_lock(&integrity_iint_lock);
146 iint = __integrity_iint_find(inode);
147 rb_erase(&iint->rb_node, &integrity_iint_tree);
148 spin_unlock(&integrity_iint_lock);
149
150 iint_free(iint);
151}
152
153static void init_once(void *foo)
154{
155 struct integrity_iint_cache *iint = foo;
156
157 memset(iint, 0, sizeof *iint);
158 iint->version = 0;
159 iint->flags = 0UL;
160 mutex_init(&iint->mutex);
161 iint->evm_status = INTEGRITY_UNKNOWN;
162}
163
164static int __init integrity_iintcache_init(void)
165{
166 iint_cache =
167 kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
168 0, SLAB_PANIC, init_once);
169 iint_initialized = 1;
170 return 0;
171}
172security_initcall(integrity_iintcache_init);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2008 IBM Corporation
4 *
5 * Authors:
6 * Mimi Zohar <zohar@us.ibm.com>
7 *
8 * File: integrity_iint.c
9 * - initialize the integrity directory in securityfs
10 * - load IMA and EVM keys
11 */
12#include <linux/security.h>
13#include "integrity.h"
14
15struct dentry *integrity_dir;
16
17/*
18 * integrity_kernel_read - read data from the file
19 *
20 * This is a function for reading file content instead of kernel_read().
21 * It does not perform locking checks to ensure it cannot be blocked.
22 * It does not perform security checks because it is irrelevant for IMA.
23 *
24 */
25int integrity_kernel_read(struct file *file, loff_t offset,
26 void *addr, unsigned long count)
27{
28 return __kernel_read(file, addr, count, &offset);
29}
30
31/*
32 * integrity_load_keys - load integrity keys hook
33 *
34 * Hooks is called from init/main.c:kernel_init_freeable()
35 * when rootfs is ready
36 */
37void __init integrity_load_keys(void)
38{
39 ima_load_x509();
40
41 if (!IS_ENABLED(CONFIG_IMA_LOAD_X509))
42 evm_load_x509();
43}
44
45static int __init integrity_fs_init(void)
46{
47 integrity_dir = securityfs_create_dir("integrity", NULL);
48 if (IS_ERR(integrity_dir)) {
49 int ret = PTR_ERR(integrity_dir);
50
51 if (ret != -ENODEV)
52 pr_err("Unable to create integrity sysfs dir: %d\n",
53 ret);
54 integrity_dir = NULL;
55 return ret;
56 }
57
58 return 0;
59}
60
61late_initcall(integrity_fs_init)