mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
854fdd55bf
Now that i_readcount is maintained by the VFS layer, remove the imbalance checking in IMA. Cleans up the IMA code nicely. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
170 lines
3.5 KiB
C
170 lines
3.5 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: ima_iint.c
|
|
* - implements the IMA hooks: ima_inode_alloc, ima_inode_free
|
|
* - cache integrity information associated with an inode
|
|
* using a rbtree tree.
|
|
*/
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/rbtree.h>
|
|
#include "ima.h"
|
|
|
|
static struct rb_root ima_iint_tree = RB_ROOT;
|
|
static DEFINE_SPINLOCK(ima_iint_lock);
|
|
static struct kmem_cache *iint_cache __read_mostly;
|
|
|
|
int iint_initialized = 0;
|
|
|
|
/*
|
|
* __ima_iint_find - return the iint associated with an inode
|
|
*/
|
|
static struct ima_iint_cache *__ima_iint_find(struct inode *inode)
|
|
{
|
|
struct ima_iint_cache *iint;
|
|
struct rb_node *n = ima_iint_tree.rb_node;
|
|
|
|
assert_spin_locked(&ima_iint_lock);
|
|
|
|
while (n) {
|
|
iint = rb_entry(n, struct ima_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;
|
|
}
|
|
|
|
/*
|
|
* ima_iint_find - return the iint associated with an inode
|
|
*/
|
|
struct ima_iint_cache *ima_iint_find(struct inode *inode)
|
|
{
|
|
struct ima_iint_cache *iint;
|
|
|
|
if (!IS_IMA(inode))
|
|
return NULL;
|
|
|
|
spin_lock(&ima_iint_lock);
|
|
iint = __ima_iint_find(inode);
|
|
spin_unlock(&ima_iint_lock);
|
|
|
|
return iint;
|
|
}
|
|
|
|
static void iint_free(struct ima_iint_cache *iint)
|
|
{
|
|
iint->version = 0;
|
|
iint->flags = 0UL;
|
|
kmem_cache_free(iint_cache, iint);
|
|
}
|
|
|
|
/**
|
|
* ima_inode_alloc - allocate an iint associated with an inode
|
|
* @inode: pointer to the inode
|
|
*/
|
|
int ima_inode_alloc(struct inode *inode)
|
|
{
|
|
struct rb_node **p;
|
|
struct rb_node *new_node, *parent = NULL;
|
|
struct ima_iint_cache *new_iint, *test_iint;
|
|
int rc;
|
|
|
|
new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
|
|
if (!new_iint)
|
|
return -ENOMEM;
|
|
|
|
new_iint->inode = inode;
|
|
new_node = &new_iint->rb_node;
|
|
|
|
mutex_lock(&inode->i_mutex); /* i_flags */
|
|
spin_lock(&ima_iint_lock);
|
|
|
|
p = &ima_iint_tree.rb_node;
|
|
while (*p) {
|
|
parent = *p;
|
|
test_iint = rb_entry(parent, struct ima_iint_cache, rb_node);
|
|
|
|
rc = -EEXIST;
|
|
if (inode < test_iint->inode)
|
|
p = &(*p)->rb_left;
|
|
else if (inode > test_iint->inode)
|
|
p = &(*p)->rb_right;
|
|
else
|
|
goto out_err;
|
|
}
|
|
|
|
inode->i_flags |= S_IMA;
|
|
rb_link_node(new_node, parent, p);
|
|
rb_insert_color(new_node, &ima_iint_tree);
|
|
|
|
spin_unlock(&ima_iint_lock);
|
|
mutex_unlock(&inode->i_mutex); /* i_flags */
|
|
|
|
return 0;
|
|
out_err:
|
|
spin_unlock(&ima_iint_lock);
|
|
mutex_unlock(&inode->i_mutex); /* i_flags */
|
|
iint_free(new_iint);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* ima_inode_free - called on security_inode_free
|
|
* @inode: pointer to the inode
|
|
*
|
|
* Free the integrity information(iint) associated with an inode.
|
|
*/
|
|
void ima_inode_free(struct inode *inode)
|
|
{
|
|
struct ima_iint_cache *iint;
|
|
|
|
if (!IS_IMA(inode))
|
|
return;
|
|
|
|
spin_lock(&ima_iint_lock);
|
|
iint = __ima_iint_find(inode);
|
|
rb_erase(&iint->rb_node, &ima_iint_tree);
|
|
spin_unlock(&ima_iint_lock);
|
|
|
|
iint_free(iint);
|
|
}
|
|
|
|
static void init_once(void *foo)
|
|
{
|
|
struct ima_iint_cache *iint = foo;
|
|
|
|
memset(iint, 0, sizeof *iint);
|
|
iint->version = 0;
|
|
iint->flags = 0UL;
|
|
mutex_init(&iint->mutex);
|
|
}
|
|
|
|
static int __init ima_iintcache_init(void)
|
|
{
|
|
iint_cache =
|
|
kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
|
|
SLAB_PANIC, init_once);
|
|
iint_initialized = 1;
|
|
return 0;
|
|
}
|
|
security_initcall(ima_iintcache_init);
|