diff options
| author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
|---|---|---|
| committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
| commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
| tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /security/integrity | |
| parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) | |
Diffstat (limited to 'security/integrity')
| -rw-r--r-- | security/integrity/ima/ima_iint.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c new file mode 100644 index 00000000000..4ae73040ab7 --- /dev/null +++ b/security/integrity/ima/ima_iint.c | |||
| @@ -0,0 +1,169 @@ | |||
| 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: ima_iint.c | ||
| 13 | * - implements the IMA hooks: ima_inode_alloc, ima_inode_free | ||
| 14 | * - cache integrity information associated with an inode | ||
| 15 | * using a rbtree tree. | ||
| 16 | */ | ||
| 17 | #include <linux/slab.h> | ||
| 18 | #include <linux/module.h> | ||
| 19 | #include <linux/spinlock.h> | ||
| 20 | #include <linux/rbtree.h> | ||
| 21 | #include "ima.h" | ||
| 22 | |||
| 23 | static struct rb_root ima_iint_tree = RB_ROOT; | ||
| 24 | static DEFINE_SPINLOCK(ima_iint_lock); | ||
| 25 | static struct kmem_cache *iint_cache __read_mostly; | ||
| 26 | |||
| 27 | int iint_initialized = 0; | ||
| 28 | |||
| 29 | /* | ||
| 30 | * __ima_iint_find - return the iint associated with an inode | ||
| 31 | */ | ||
| 32 | static struct ima_iint_cache *__ima_iint_find(struct inode *inode) | ||
| 33 | { | ||
| 34 | struct ima_iint_cache *iint; | ||
| 35 | struct rb_node *n = ima_iint_tree.rb_node; | ||
| 36 | |||
| 37 | assert_spin_locked(&ima_iint_lock); | ||
| 38 | |||
| 39 | while (n) { | ||
| 40 | iint = rb_entry(n, struct ima_iint_cache, rb_node); | ||
| 41 | |||
| 42 | if (inode < iint->inode) | ||
| 43 | n = n->rb_left; | ||
| 44 | else if (inode > iint->inode) | ||
| 45 | n = n->rb_right; | ||
| 46 | else | ||
| 47 | break; | ||
| 48 | } | ||
| 49 | if (!n) | ||
| 50 | return NULL; | ||
| 51 | |||
| 52 | return iint; | ||
| 53 | } | ||
| 54 | |||
| 55 | /* | ||
| 56 | * ima_iint_find - return the iint associated with an inode | ||
| 57 | */ | ||
| 58 | struct ima_iint_cache *ima_iint_find(struct inode *inode) | ||
| 59 | { | ||
| 60 | struct ima_iint_cache *iint; | ||
| 61 | |||
| 62 | if (!IS_IMA(inode)) | ||
| 63 | return NULL; | ||
| 64 | |||
| 65 | spin_lock(&ima_iint_lock); | ||
| 66 | iint = __ima_iint_find(inode); | ||
| 67 | spin_unlock(&ima_iint_lock); | ||
| 68 | |||
| 69 | return iint; | ||
| 70 | } | ||
| 71 | |||
| 72 | static void iint_free(struct ima_iint_cache *iint) | ||
| 73 | { | ||
| 74 | iint->version = 0; | ||
| 75 | iint->flags = 0UL; | ||
| 76 | kmem_cache_free(iint_cache, iint); | ||
| 77 | } | ||
| 78 | |||
| 79 | /** | ||
| 80 | * ima_inode_alloc - allocate an iint associated with an inode | ||
| 81 | * @inode: pointer to the inode | ||
| 82 | */ | ||
| 83 | int ima_inode_alloc(struct inode *inode) | ||
| 84 | { | ||
| 85 | struct rb_node **p; | ||
| 86 | struct rb_node *new_node, *parent = NULL; | ||
| 87 | struct ima_iint_cache *new_iint, *test_iint; | ||
| 88 | int rc; | ||
| 89 | |||
| 90 | new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS); | ||
| 91 | if (!new_iint) | ||
| 92 | return -ENOMEM; | ||
| 93 | |||
| 94 | new_iint->inode = inode; | ||
| 95 | new_node = &new_iint->rb_node; | ||
| 96 | |||
| 97 | mutex_lock(&inode->i_mutex); /* i_flags */ | ||
| 98 | spin_lock(&ima_iint_lock); | ||
| 99 | |||
| 100 | p = &ima_iint_tree.rb_node; | ||
| 101 | while (*p) { | ||
| 102 | parent = *p; | ||
| 103 | test_iint = rb_entry(parent, struct ima_iint_cache, rb_node); | ||
| 104 | |||
| 105 | rc = -EEXIST; | ||
| 106 | if (inode < test_iint->inode) | ||
| 107 | p = &(*p)->rb_left; | ||
| 108 | else if (inode > test_iint->inode) | ||
| 109 | p = &(*p)->rb_right; | ||
| 110 | else | ||
| 111 | goto out_err; | ||
| 112 | } | ||
| 113 | |||
| 114 | inode->i_flags |= S_IMA; | ||
| 115 | rb_link_node(new_node, parent, p); | ||
| 116 | rb_insert_color(new_node, &ima_iint_tree); | ||
| 117 | |||
| 118 | spin_unlock(&ima_iint_lock); | ||
| 119 | mutex_unlock(&inode->i_mutex); /* i_flags */ | ||
| 120 | |||
| 121 | return 0; | ||
| 122 | out_err: | ||
| 123 | spin_unlock(&ima_iint_lock); | ||
| 124 | mutex_unlock(&inode->i_mutex); /* i_flags */ | ||
| 125 | iint_free(new_iint); | ||
| 126 | |||
| 127 | return rc; | ||
| 128 | } | ||
| 129 | |||
| 130 | /** | ||
| 131 | * ima_inode_free - called on security_inode_free | ||
| 132 | * @inode: pointer to the inode | ||
| 133 | * | ||
| 134 | * Free the integrity information(iint) associated with an inode. | ||
| 135 | */ | ||
| 136 | void ima_inode_free(struct inode *inode) | ||
| 137 | { | ||
| 138 | struct ima_iint_cache *iint; | ||
| 139 | |||
| 140 | if (!IS_IMA(inode)) | ||
| 141 | return; | ||
| 142 | |||
| 143 | spin_lock(&ima_iint_lock); | ||
| 144 | iint = __ima_iint_find(inode); | ||
| 145 | rb_erase(&iint->rb_node, &ima_iint_tree); | ||
| 146 | spin_unlock(&ima_iint_lock); | ||
| 147 | |||
| 148 | iint_free(iint); | ||
| 149 | } | ||
| 150 | |||
| 151 | static void init_once(void *foo) | ||
| 152 | { | ||
| 153 | struct ima_iint_cache *iint = foo; | ||
| 154 | |||
| 155 | memset(iint, 0, sizeof *iint); | ||
| 156 | iint->version = 0; | ||
| 157 | iint->flags = 0UL; | ||
| 158 | mutex_init(&iint->mutex); | ||
| 159 | } | ||
| 160 | |||
| 161 | static int __init ima_iintcache_init(void) | ||
| 162 | { | ||
| 163 | iint_cache = | ||
| 164 | kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0, | ||
| 165 | SLAB_PANIC, init_once); | ||
| 166 | iint_initialized = 1; | ||
| 167 | return 0; | ||
| 168 | } | ||
| 169 | security_initcall(ima_iintcache_init); | ||
