1 /* CacheFiles security management
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
13 #include <linux/cred.h>
17 * determine the security context within which we access the cache from within
20 int cachefiles_get_security_ID(struct cachefiles_cache *cache)
25 _enter("{%s}", cache->secctx);
27 new = prepare_kernel_cred(current);
34 ret = set_security_override_from_ctx(new, cache->secctx);
37 printk(KERN_ERR "CacheFiles:"
38 " Security denies permission to nominate"
39 " security context: error %d\n",
45 cache->cache_cred = new;
53 * see if mkdir and create can be performed in the root directory
55 static int cachefiles_check_cache_dir(struct cachefiles_cache *cache,
60 ret = security_inode_mkdir(root->d_inode, root, 0);
62 printk(KERN_ERR "CacheFiles:"
63 " Security denies permission to make dirs: error %d",
68 ret = security_inode_create(root->d_inode, root, 0);
70 printk(KERN_ERR "CacheFiles:"
71 " Security denies permission to create files: error %d",
78 * check the security details of the on-disk cache
79 * - must be called with security override in force
80 * - must return with a security override in force - even in the case of an
83 int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
85 const struct cred **_saved_cred)
92 /* duplicate the cache creds for COW (the override is currently in
93 * force, so we can use prepare_creds() to do this) */
94 new = prepare_creds();
98 cachefiles_end_secure(cache, *_saved_cred);
100 /* use the cache root dir's security context as the basis with
101 * which create files */
102 ret = set_create_files_as(new, root->d_inode);
105 cachefiles_begin_secure(cache, _saved_cred);
106 _leave(" = %d [cfa]", ret);
110 put_cred(cache->cache_cred);
111 cache->cache_cred = new;
113 cachefiles_begin_secure(cache, _saved_cred);
114 ret = cachefiles_check_cache_dir(cache, root);
116 if (ret == -EOPNOTSUPP)
118 _leave(" = %d", ret);