diff options
author | John Johansen <john.johansen@canonical.com> | 2010-07-29 17:48:00 -0400 |
---|---|---|
committer | James Morris <jmorris@namei.org> | 2010-08-02 01:38:37 -0400 |
commit | c88d4c7b049e87998ac0a9f455aa545cc895ef92 (patch) | |
tree | 1859582b4afec1116b6831ea89ae27c35209991a /security/apparmor | |
parent | 736ec752d95e91e77cc0e8c97c057ab076ac2f51 (diff) |
AppArmor: core policy routines
The basic routines and defines for AppArmor policy. AppArmor policy
is defined by a few basic components.
profiles - the basic unit of confinement contain all the information
to enforce policy on a task
Profiles tend to be named after an executable that they
will attach to but this is not required.
namespaces - a container for a set of profiles that will be used
during attachment and transitions between profiles.
sids - which provide a unique id for each profile
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/apparmor')
-rw-r--r-- | security/apparmor/include/policy.h | 305 | ||||
-rw-r--r-- | security/apparmor/include/sid.h | 24 | ||||
-rw-r--r-- | security/apparmor/policy.c | 1184 | ||||
-rw-r--r-- | security/apparmor/sid.c | 55 |
4 files changed, 1568 insertions, 0 deletions
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h new file mode 100644 index 000000000000..aeda5cf56904 --- /dev/null +++ b/security/apparmor/include/policy.h | |||
@@ -0,0 +1,305 @@ | |||
1 | /* | ||
2 | * AppArmor security module | ||
3 | * | ||
4 | * This file contains AppArmor policy definitions. | ||
5 | * | ||
6 | * Copyright (C) 1998-2008 Novell/SUSE | ||
7 | * Copyright 2009-2010 Canonical Ltd. | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or | ||
10 | * modify it under the terms of the GNU General Public License as | ||
11 | * published by the Free Software Foundation, version 2 of the | ||
12 | * License. | ||
13 | */ | ||
14 | |||
15 | #ifndef __AA_POLICY_H | ||
16 | #define __AA_POLICY_H | ||
17 | |||
18 | #include <linux/capability.h> | ||
19 | #include <linux/cred.h> | ||
20 | #include <linux/kref.h> | ||
21 | #include <linux/sched.h> | ||
22 | #include <linux/slab.h> | ||
23 | #include <linux/socket.h> | ||
24 | |||
25 | #include "apparmor.h" | ||
26 | #include "audit.h" | ||
27 | #include "capability.h" | ||
28 | #include "domain.h" | ||
29 | #include "file.h" | ||
30 | #include "resource.h" | ||
31 | |||
32 | extern const char *profile_mode_names[]; | ||
33 | #define APPARMOR_NAMES_MAX_INDEX 3 | ||
34 | |||
35 | #define COMPLAIN_MODE(_profile) \ | ||
36 | ((aa_g_profile_mode == APPARMOR_COMPLAIN) || \ | ||
37 | ((_profile)->mode == APPARMOR_COMPLAIN)) | ||
38 | |||
39 | #define KILL_MODE(_profile) \ | ||
40 | ((aa_g_profile_mode == APPARMOR_KILL) || \ | ||
41 | ((_profile)->mode == APPARMOR_KILL)) | ||
42 | |||
43 | #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT) | ||
44 | |||
45 | /* | ||
46 | * FIXME: currently need a clean way to replace and remove profiles as a | ||
47 | * set. It should be done at the namespace level. | ||
48 | * Either, with a set of profiles loaded at the namespace level or via | ||
49 | * a mark and remove marked interface. | ||
50 | */ | ||
51 | enum profile_mode { | ||
52 | APPARMOR_ENFORCE, /* enforce access rules */ | ||
53 | APPARMOR_COMPLAIN, /* allow and log access violations */ | ||
54 | APPARMOR_KILL, /* kill task on access violation */ | ||
55 | }; | ||
56 | |||
57 | enum profile_flags { | ||
58 | PFLAG_HAT = 1, /* profile is a hat */ | ||
59 | PFLAG_UNCONFINED = 2, /* profile is an unconfined profile */ | ||
60 | PFLAG_NULL = 4, /* profile is null learning profile */ | ||
61 | PFLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ | ||
62 | PFLAG_IMMUTABLE = 0x10, /* don't allow changes/replacement */ | ||
63 | PFLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ | ||
64 | PFLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ | ||
65 | PFLAG_OLD_NULL_TRANS = 0x100, /* use // as the null transition */ | ||
66 | |||
67 | /* These flags must correspond with PATH_flags */ | ||
68 | PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */ | ||
69 | }; | ||
70 | |||
71 | struct aa_profile; | ||
72 | |||
73 | /* struct aa_policy - common part of both namespaces and profiles | ||
74 | * @name: name of the object | ||
75 | * @hname - The hierarchical name | ||
76 | * @count: reference count of the obj | ||
77 | * @list: list policy object is on | ||
78 | * @profiles: head of the profiles list contained in the object | ||
79 | */ | ||
80 | struct aa_policy { | ||
81 | char *name; | ||
82 | char *hname; | ||
83 | struct kref count; | ||
84 | struct list_head list; | ||
85 | struct list_head profiles; | ||
86 | }; | ||
87 | |||
88 | /* struct aa_ns_acct - accounting of profiles in namespace | ||
89 | * @max_size: maximum space allowed for all profiles in namespace | ||
90 | * @max_count: maximum number of profiles that can be in this namespace | ||
91 | * @size: current size of profiles | ||
92 | * @count: current count of profiles (includes null profiles) | ||
93 | */ | ||
94 | struct aa_ns_acct { | ||
95 | int max_size; | ||
96 | int max_count; | ||
97 | int size; | ||
98 | int count; | ||
99 | }; | ||
100 | |||
101 | /* struct aa_namespace - namespace for a set of profiles | ||
102 | * @base: common policy | ||
103 | * @parent: parent of namespace | ||
104 | * @lock: lock for modifying the object | ||
105 | * @acct: accounting for the namespace | ||
106 | * @unconfined: special unconfined profile for the namespace | ||
107 | * @sub_ns: list of namespaces under the current namespace. | ||
108 | * | ||
109 | * An aa_namespace defines the set profiles that are searched to determine | ||
110 | * which profile to attach to a task. Profiles can not be shared between | ||
111 | * aa_namespaces and profile names within a namespace are guaranteed to be | ||
112 | * unique. When profiles in separate namespaces have the same name they | ||
113 | * are NOT considered to be equivalent. | ||
114 | * | ||
115 | * Namespaces are hierarchical and only namespaces and profiles below the | ||
116 | * current namespace are visible. | ||
117 | * | ||
118 | * Namespace names must be unique and can not contain the characters :/\0 | ||
119 | * | ||
120 | * FIXME TODO: add vserver support of namespaces (can it all be done in | ||
121 | * userspace?) | ||
122 | */ | ||
123 | struct aa_namespace { | ||
124 | struct aa_policy base; | ||
125 | struct aa_namespace *parent; | ||
126 | rwlock_t lock; | ||
127 | struct aa_ns_acct acct; | ||
128 | struct aa_profile *unconfined; | ||
129 | struct list_head sub_ns; | ||
130 | }; | ||
131 | |||
132 | /* struct aa_profile - basic confinement data | ||
133 | * @base - base components of the profile (name, refcount, lists, lock ...) | ||
134 | * @parent: parent of profile | ||
135 | * @ns: namespace the profile is in | ||
136 | * @replacedby: is set to the profile that replaced this profile | ||
137 | * @rename: optional profile name that this profile renamed | ||
138 | * @xmatch: optional extended matching for unconfined executables names | ||
139 | * @xmatch_len: xmatch prefix len, used to determine xmatch priority | ||
140 | * @sid: the unique security id number of this profile | ||
141 | * @audit: the auditing mode of the profile | ||
142 | * @mode: the enforcement mode of the profile | ||
143 | * @flags: flags controlling profile behavior | ||
144 | * @path_flags: flags controlling path generation behavior | ||
145 | * @size: the memory consumed by this profiles rules | ||
146 | * @file: The set of rules governing basic file access and domain transitions | ||
147 | * @caps: capabilities for the profile | ||
148 | * @rlimits: rlimits for the profile | ||
149 | * | ||
150 | * The AppArmor profile contains the basic confinement data. Each profile | ||
151 | * has a name, and exists in a namespace. The @name and @exec_match are | ||
152 | * used to determine profile attachment against unconfined tasks. All other | ||
153 | * attachments are determined by profile X transition rules. | ||
154 | * | ||
155 | * The @replacedby field is write protected by the profile lock. Reads | ||
156 | * are assumed to be atomic, and are done without locking. | ||
157 | * | ||
158 | * Profiles have a hierarchy where hats and children profiles keep | ||
159 | * a reference to their parent. | ||
160 | * | ||
161 | * Profile names can not begin with a : and can not contain the \0 | ||
162 | * character. If a profile name begins with / it will be considered when | ||
163 | * determining profile attachment on "unconfined" tasks. | ||
164 | */ | ||
165 | struct aa_profile { | ||
166 | struct aa_policy base; | ||
167 | struct aa_profile *parent; | ||
168 | |||
169 | struct aa_namespace *ns; | ||
170 | struct aa_profile *replacedby; | ||
171 | const char *rename; | ||
172 | |||
173 | struct aa_dfa *xmatch; | ||
174 | int xmatch_len; | ||
175 | u32 sid; | ||
176 | enum audit_mode audit; | ||
177 | enum profile_mode mode; | ||
178 | u32 flags; | ||
179 | u32 path_flags; | ||
180 | int size; | ||
181 | |||
182 | struct aa_file_rules file; | ||
183 | struct aa_caps caps; | ||
184 | struct aa_rlimit rlimits; | ||
185 | }; | ||
186 | |||
187 | extern struct aa_namespace *root_ns; | ||
188 | extern enum profile_mode aa_g_profile_mode; | ||
189 | |||
190 | void aa_add_profile(struct aa_policy *common, struct aa_profile *profile); | ||
191 | |||
192 | bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view); | ||
193 | const char *aa_ns_name(struct aa_namespace *parent, struct aa_namespace *child); | ||
194 | int aa_alloc_root_ns(void); | ||
195 | void aa_free_root_ns(void); | ||
196 | void aa_free_namespace_kref(struct kref *kref); | ||
197 | |||
198 | struct aa_namespace *aa_find_namespace(struct aa_namespace *root, | ||
199 | const char *name); | ||
200 | |||
201 | static inline struct aa_policy *aa_get_common(struct aa_policy *c) | ||
202 | { | ||
203 | if (c) | ||
204 | kref_get(&c->count); | ||
205 | |||
206 | return c; | ||
207 | } | ||
208 | |||
209 | /** | ||
210 | * aa_get_namespace - increment references count on @ns | ||
211 | * @ns: namespace to increment reference count of (MAYBE NULL) | ||
212 | * | ||
213 | * Returns: pointer to @ns, if @ns is NULL returns NULL | ||
214 | * Requires: @ns must be held with valid refcount when called | ||
215 | */ | ||
216 | static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns) | ||
217 | { | ||
218 | if (ns) | ||
219 | kref_get(&(ns->base.count)); | ||
220 | |||
221 | return ns; | ||
222 | } | ||
223 | |||
224 | /** | ||
225 | * aa_put_namespace - decrement refcount on @ns | ||
226 | * @ns: namespace to put reference of | ||
227 | * | ||
228 | * Decrement reference count of @ns and if no longer in use free it | ||
229 | */ | ||
230 | static inline void aa_put_namespace(struct aa_namespace *ns) | ||
231 | { | ||
232 | if (ns) | ||
233 | kref_put(&ns->base.count, aa_free_namespace_kref); | ||
234 | } | ||
235 | |||
236 | struct aa_profile *aa_alloc_profile(const char *name); | ||
237 | struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat); | ||
238 | void aa_free_profile_kref(struct kref *kref); | ||
239 | struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name); | ||
240 | struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *name); | ||
241 | struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name); | ||
242 | |||
243 | ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace); | ||
244 | ssize_t aa_remove_profiles(char *name, size_t size); | ||
245 | |||
246 | #define PROF_ADD 1 | ||
247 | #define PROF_REPLACE 0 | ||
248 | |||
249 | #define unconfined(X) ((X)->flags & PFLAG_UNCONFINED) | ||
250 | |||
251 | /** | ||
252 | * aa_newest_version - find the newest version of @profile | ||
253 | * @profile: the profile to check for newer versions of (NOT NULL) | ||
254 | * | ||
255 | * Returns: newest version of @profile, if @profile is the newest version | ||
256 | * return @profile. | ||
257 | * | ||
258 | * NOTE: the profile returned is not refcounted, The refcount on @profile | ||
259 | * must be held until the caller decides what to do with the returned newest | ||
260 | * version. | ||
261 | */ | ||
262 | static inline struct aa_profile *aa_newest_version(struct aa_profile *profile) | ||
263 | { | ||
264 | while (profile->replacedby) | ||
265 | profile = profile->replacedby; | ||
266 | |||
267 | return profile; | ||
268 | } | ||
269 | |||
270 | /** | ||
271 | * aa_get_profile - increment refcount on profile @p | ||
272 | * @p: profile (MAYBE NULL) | ||
273 | * | ||
274 | * Returns: pointer to @p if @p is NULL will return NULL | ||
275 | * Requires: @p must be held with valid refcount when called | ||
276 | */ | ||
277 | static inline struct aa_profile *aa_get_profile(struct aa_profile *p) | ||
278 | { | ||
279 | if (p) | ||
280 | kref_get(&(p->base.count)); | ||
281 | |||
282 | return p; | ||
283 | } | ||
284 | |||
285 | /** | ||
286 | * aa_put_profile - decrement refcount on profile @p | ||
287 | * @p: profile (MAYBE NULL) | ||
288 | */ | ||
289 | static inline void aa_put_profile(struct aa_profile *p) | ||
290 | { | ||
291 | if (p) | ||
292 | kref_put(&p->base.count, aa_free_profile_kref); | ||
293 | } | ||
294 | |||
295 | static inline int AUDIT_MODE(struct aa_profile *profile) | ||
296 | { | ||
297 | if (aa_g_audit != AUDIT_NORMAL) | ||
298 | return aa_g_audit; | ||
299 | |||
300 | return profile->audit; | ||
301 | } | ||
302 | |||
303 | bool aa_may_manage_policy(int op); | ||
304 | |||
305 | #endif /* __AA_POLICY_H */ | ||
diff --git a/security/apparmor/include/sid.h b/security/apparmor/include/sid.h new file mode 100644 index 000000000000..020db35c3010 --- /dev/null +++ b/security/apparmor/include/sid.h | |||
@@ -0,0 +1,24 @@ | |||
1 | /* | ||
2 | * AppArmor security module | ||
3 | * | ||
4 | * This file contains AppArmor security identifier (sid) definitions | ||
5 | * | ||
6 | * Copyright 2009-2010 Canonical Ltd. | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or | ||
9 | * modify it under the terms of the GNU General Public License as | ||
10 | * published by the Free Software Foundation, version 2 of the | ||
11 | * License. | ||
12 | */ | ||
13 | |||
14 | #ifndef __AA_SID_H | ||
15 | #define __AA_SID_H | ||
16 | |||
17 | #include <linux/types.h> | ||
18 | |||
19 | struct aa_profile; | ||
20 | |||
21 | u32 aa_alloc_sid(void); | ||
22 | void aa_free_sid(u32 sid); | ||
23 | |||
24 | #endif /* __AA_SID_H */ | ||
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c new file mode 100644 index 000000000000..3cdc1ad0787e --- /dev/null +++ b/security/apparmor/policy.c | |||
@@ -0,0 +1,1184 @@ | |||
1 | /* | ||
2 | * AppArmor security module | ||
3 | * | ||
4 | * This file contains AppArmor policy manipulation functions | ||
5 | * | ||
6 | * Copyright (C) 1998-2008 Novell/SUSE | ||
7 | * Copyright 2009-2010 Canonical Ltd. | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or | ||
10 | * modify it under the terms of the GNU General Public License as | ||
11 | * published by the Free Software Foundation, version 2 of the | ||
12 | * License. | ||
13 | * | ||
14 | * | ||
15 | * AppArmor policy is based around profiles, which contain the rules a | ||
16 | * task is confined by. Every task in the system has a profile attached | ||
17 | * to it determined either by matching "unconfined" tasks against the | ||
18 | * visible set of profiles or by following a profiles attachment rules. | ||
19 | * | ||
20 | * Each profile exists in a profile namespace which is a container of | ||
21 | * visible profiles. Each namespace contains a special "unconfined" profile, | ||
22 | * which doesn't enforce any confinement on a task beyond DAC. | ||
23 | * | ||
24 | * Namespace and profile names can be written together in either | ||
25 | * of two syntaxes. | ||
26 | * :namespace:profile - used by kernel interfaces for easy detection | ||
27 | * namespace://profile - used by policy | ||
28 | * | ||
29 | * Profile names can not start with : or @ or ^ and may not contain \0 | ||
30 | * | ||
31 | * Reserved profile names | ||
32 | * unconfined - special automatically generated unconfined profile | ||
33 | * inherit - special name to indicate profile inheritance | ||
34 | * null-XXXX-YYYY - special automatically generated learning profiles | ||
35 | * | ||
36 | * Namespace names may not start with / or @ and may not contain \0 or : | ||
37 | * Reserved namespace names | ||
38 | * user-XXXX - user defined profiles | ||
39 | * | ||
40 | * a // in a profile or namespace name indicates a hierarchical name with the | ||
41 | * name before the // being the parent and the name after the child. | ||
42 | * | ||
43 | * Profile and namespace hierarchies serve two different but similar purposes. | ||
44 | * The namespace contains the set of visible profiles that are considered | ||
45 | * for attachment. The hierarchy of namespaces allows for virtualizing | ||
46 | * the namespace so that for example a chroot can have its own set of profiles | ||
47 | * which may define some local user namespaces. | ||
48 | * The profile hierarchy severs two distinct purposes, | ||
49 | * - it allows for sub profiles or hats, which allows an application to run | ||
50 | * subprograms under its own profile with different restriction than it | ||
51 | * self, and not have it use the system profile. | ||
52 | * eg. if a mail program starts an editor, the policy might make the | ||
53 | * restrictions tighter on the editor tighter than the mail program, | ||
54 | * and definitely different than general editor restrictions | ||
55 | * - it allows for binary hierarchy of profiles, so that execution history | ||
56 | * is preserved. This feature isn't exploited by AppArmor reference policy | ||
57 | * but is allowed. NOTE: this is currently suboptimal because profile | ||
58 | * aliasing is not currently implemented so that a profile for each | ||
59 | * level must be defined. | ||
60 | * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started | ||
61 | * from /bin/bash | ||
62 | * | ||
63 | * A profile or namespace name that can contain one or more // separators | ||
64 | * is referred to as an hname (hierarchical). | ||
65 | * eg. /bin/bash//bin/ls | ||
66 | * | ||
67 | * An fqname is a name that may contain both namespace and profile hnames. | ||
68 | * eg. :ns:/bin/bash//bin/ls | ||
69 | * | ||
70 | * NOTES: | ||
71 | * - locking of profile lists is currently fairly coarse. All profile | ||
72 | * lists within a namespace use the namespace lock. | ||
73 | * FIXME: move profile lists to using rcu_lists | ||
74 | */ | ||
75 | |||
76 | #include <linux/slab.h> | ||
77 | #include <linux/spinlock.h> | ||
78 | #include <linux/string.h> | ||
79 | |||
80 | #include "include/apparmor.h" | ||
81 | #include "include/capability.h" | ||
82 | #include "include/context.h" | ||
83 | #include "include/file.h" | ||
84 | #include "include/ipc.h" | ||
85 | #include "include/match.h" | ||
86 | #include "include/path.h" | ||
87 | #include "include/policy.h" | ||
88 | #include "include/policy_unpack.h" | ||
89 | #include "include/resource.h" | ||
90 | #include "include/sid.h" | ||
91 | |||
92 | |||
93 | /* root profile namespace */ | ||
94 | struct aa_namespace *root_ns; | ||
95 | |||
96 | const char *profile_mode_names[] = { | ||
97 | "enforce", | ||
98 | "complain", | ||
99 | "kill", | ||
100 | }; | ||
101 | |||
102 | /** | ||
103 | * hname_tail - find the last component of an hname | ||
104 | * @name: hname to find the base profile name component of (NOT NULL) | ||
105 | * | ||
106 | * Returns: the tail (base profile name) name component of an hname | ||
107 | */ | ||
108 | static const char *hname_tail(const char *hname) | ||
109 | { | ||
110 | char *split; | ||
111 | hname = strim((char *)hname); | ||
112 | for (split = strstr(hname, "//"); split; split = strstr(hname, "//")) | ||
113 | hname = split + 2; | ||
114 | |||
115 | return hname; | ||
116 | } | ||
117 | |||
118 | /** | ||
119 | * policy_init - initialize a policy structure | ||
120 | * @policy: policy to initialize (NOT NULL) | ||
121 | * @prefix: prefix name if any is required. (MAYBE NULL) | ||
122 | * @name: name of the policy, init will make a copy of it (NOT NULL) | ||
123 | * | ||
124 | * Note: this fn creates a copy of strings passed in | ||
125 | * | ||
126 | * Returns: true if policy init successful | ||
127 | */ | ||
128 | static bool policy_init(struct aa_policy *policy, const char *prefix, | ||
129 | const char *name) | ||
130 | { | ||
131 | /* freed by policy_free */ | ||
132 | if (prefix) { | ||
133 | policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3, | ||
134 | GFP_KERNEL); | ||
135 | if (policy->hname) | ||
136 | sprintf(policy->hname, "%s//%s", prefix, name); | ||
137 | } else | ||
138 | policy->hname = kstrdup(name, GFP_KERNEL); | ||
139 | if (!policy->hname) | ||
140 | return 0; | ||
141 | /* base.name is a substring of fqname */ | ||
142 | policy->name = (char *)hname_tail(policy->hname); | ||
143 | INIT_LIST_HEAD(&policy->list); | ||
144 | INIT_LIST_HEAD(&policy->profiles); | ||
145 | kref_init(&policy->count); | ||
146 | |||
147 | return 1; | ||
148 | } | ||
149 | |||
150 | /** | ||
151 | * policy_destroy - free the elements referenced by @policy | ||
152 | * @policy: policy that is to have its elements freed (NOT NULL) | ||
153 | */ | ||
154 | static void policy_destroy(struct aa_policy *policy) | ||
155 | { | ||
156 | /* still contains profiles -- invalid */ | ||
157 | if (!list_empty(&policy->profiles)) { | ||
158 | AA_ERROR("%s: internal error, " | ||
159 | "policy '%s' still contains profiles\n", | ||
160 | __func__, policy->name); | ||
161 | BUG(); | ||
162 | } | ||
163 | if (!list_empty(&policy->list)) { | ||
164 | AA_ERROR("%s: internal error, policy '%s' still on list\n", | ||
165 | __func__, policy->name); | ||
166 | BUG(); | ||
167 | } | ||
168 | |||
169 | /* don't free name as its a subset of hname */ | ||
170 | kzfree(policy->hname); | ||
171 | } | ||
172 | |||
173 | /** | ||
174 | * __policy_find - find a policy by @name on a policy list | ||
175 | * @head: list to search (NOT NULL) | ||
176 | * @name: name to search for (NOT NULL) | ||
177 | * | ||
178 | * Requires: correct locks for the @head list be held | ||
179 | * | ||
180 | * Returns: unrefcounted policy that match @name or NULL if not found | ||
181 | */ | ||
182 | static struct aa_policy *__policy_find(struct list_head *head, const char *name) | ||
183 | { | ||
184 | struct aa_policy *policy; | ||
185 | |||
186 | list_for_each_entry(policy, head, list) { | ||
187 | if (!strcmp(policy->name, name)) | ||
188 | return policy; | ||
189 | } | ||
190 | return NULL; | ||
191 | } | ||
192 | |||
193 | /** | ||
194 | * __policy_strn_find - find a policy that's name matches @len chars of @str | ||
195 | * @head: list to search (NOT NULL) | ||
196 | * @str: string to search for (NOT NULL) | ||
197 | * @len: length of match required | ||
198 | * | ||
199 | * Requires: correct locks for the @head list be held | ||
200 | * | ||
201 | * Returns: unrefcounted policy that match @str or NULL if not found | ||
202 | * | ||
203 | * if @len == strlen(@strlen) then this is equiv to __policy_find | ||
204 | * other wise it allows searching for policy by a partial match of name | ||
205 | */ | ||
206 | static struct aa_policy *__policy_strn_find(struct list_head *head, | ||
207 | const char *str, int len) | ||
208 | { | ||
209 | struct aa_policy *policy; | ||
210 | |||
211 | list_for_each_entry(policy, head, list) { | ||
212 | if (aa_strneq(policy->name, str, len)) | ||
213 | return policy; | ||
214 | } | ||
215 | |||
216 | return NULL; | ||
217 | } | ||
218 | |||
219 | /* | ||
220 | * Routines for AppArmor namespaces | ||
221 | */ | ||
222 | |||
223 | static const char *hidden_ns_name = "---"; | ||
224 | /** | ||
225 | * aa_ns_visible - test if @view is visible from @curr | ||
226 | * @curr: namespace to treat as the parent (NOT NULL) | ||
227 | * @view: namespace to test if visible from @curr (NOT NULL) | ||
228 | * | ||
229 | * Returns: true if @view is visible from @curr else false | ||
230 | */ | ||
231 | bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view) | ||
232 | { | ||
233 | if (curr == view) | ||
234 | return true; | ||
235 | |||
236 | for ( ; view; view = view->parent) { | ||
237 | if (view->parent == curr) | ||
238 | return true; | ||
239 | } | ||
240 | return false; | ||
241 | } | ||
242 | |||
243 | /** | ||
244 | * aa_na_name - Find the ns name to display for @view from @curr | ||
245 | * @curr - current namespace (NOT NULL) | ||
246 | * @view - namespace attempting to view (NOT NULL) | ||
247 | * | ||
248 | * Returns: name of @view visible from @curr | ||
249 | */ | ||
250 | const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view) | ||
251 | { | ||
252 | /* if view == curr then the namespace name isn't displayed */ | ||
253 | if (curr == view) | ||
254 | return ""; | ||
255 | |||
256 | if (aa_ns_visible(curr, view)) { | ||
257 | /* at this point if a ns is visible it is in a view ns | ||
258 | * thus the curr ns.hname is a prefix of its name. | ||
259 | * Only output the virtualized portion of the name | ||
260 | * Add + 2 to skip over // separating curr hname prefix | ||
261 | * from the visible tail of the views hname | ||
262 | */ | ||
263 | return view->base.hname + strlen(curr->base.hname) + 2; | ||
264 | } else | ||
265 | return hidden_ns_name; | ||
266 | } | ||
267 | |||
268 | /** | ||
269 | * alloc_namespace - allocate, initialize and return a new namespace | ||
270 | * @prefix: parent namespace name (MAYBE NULL) | ||
271 | * @name: a preallocated name (NOT NULL) | ||
272 | * | ||
273 | * Returns: refcounted namespace or NULL on failure. | ||
274 | */ | ||
275 | static struct aa_namespace *alloc_namespace(const char *prefix, | ||
276 | const char *name) | ||
277 | { | ||
278 | struct aa_namespace *ns; | ||
279 | |||
280 | ns = kzalloc(sizeof(*ns), GFP_KERNEL); | ||
281 | AA_DEBUG("%s(%p)\n", __func__, ns); | ||
282 | if (!ns) | ||
283 | return NULL; | ||
284 | if (!policy_init(&ns->base, prefix, name)) | ||
285 | goto fail_ns; | ||
286 | |||
287 | INIT_LIST_HEAD(&ns->sub_ns); | ||
288 | rwlock_init(&ns->lock); | ||
289 | |||
290 | /* released by free_namespace */ | ||
291 | ns->unconfined = aa_alloc_profile("unconfined"); | ||
292 | if (!ns->unconfined) | ||
293 | goto fail_unconfined; | ||
294 | |||
295 | ns->unconfined->sid = aa_alloc_sid(); | ||
296 | ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR | | ||
297 | PFLAG_IMMUTABLE; | ||
298 | |||
299 | /* | ||
300 | * released by free_namespace, however __remove_namespace breaks | ||
301 | * the cyclic references (ns->unconfined, and unconfined->ns) and | ||
302 | * replaces with refs to parent namespace unconfined | ||
303 | */ | ||
304 | ns->unconfined->ns = aa_get_namespace(ns); | ||
305 | |||
306 | return ns; | ||
307 | |||
308 | fail_unconfined: | ||
309 | kzfree(ns->base.name); | ||
310 | fail_ns: | ||
311 | kzfree(ns); | ||
312 | return NULL; | ||
313 | } | ||
314 | |||
315 | /** | ||
316 | * free_namespace - free a profile namespace | ||
317 | * @ns: the namespace to free (MAYBE NULL) | ||
318 | * | ||
319 | * Requires: All references to the namespace must have been put, if the | ||
320 | * namespace was referenced by a profile confining a task, | ||
321 | */ | ||
322 | static void free_namespace(struct aa_namespace *ns) | ||
323 | { | ||
324 | if (!ns) | ||
325 | return; | ||
326 | |||
327 | policy_destroy(&ns->base); | ||
328 | aa_put_namespace(ns->parent); | ||
329 | |||
330 | if (ns->unconfined && ns->unconfined->ns == ns) | ||
331 | ns->unconfined->ns = NULL; | ||
332 | |||
333 | aa_put_profile(ns->unconfined); | ||
334 | kzfree(ns); | ||
335 | } | ||
336 | |||
337 | /** | ||
338 | * aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace) | ||
339 | * @kr: kref callback for freeing of a namespace (NOT NULL) | ||
340 | */ | ||
341 | void aa_free_namespace_kref(struct kref *kref) | ||
342 | { | ||
343 | free_namespace(container_of(kref, struct aa_namespace, base.count)); | ||
344 | } | ||
345 | |||
346 | /** | ||
347 | * __aa_find_namespace - find a namespace on a list by @name | ||
348 | * @head: list to search for namespace on (NOT NULL) | ||
349 | * @name: name of namespace to look for (NOT NULL) | ||
350 | * | ||
351 | * Returns: unrefcounted namespace | ||
352 | * | ||
353 | * Requires: ns lock be held | ||
354 | */ | ||
355 | static struct aa_namespace *__aa_find_namespace(struct list_head *head, | ||
356 | const char *name) | ||
357 | { | ||
358 | return (struct aa_namespace *)__policy_find(head, name); | ||
359 | } | ||
360 | |||
361 | /** | ||
362 | * aa_find_namespace - look up a profile namespace on the namespace list | ||
363 | * @root: namespace to search in (NOT NULL) | ||
364 | * @name: name of namespace to find (NOT NULL) | ||
365 | * | ||
366 | * Returns: a refcounted namespace on the list, or NULL if no namespace | ||
367 | * called @name exists. | ||
368 | * | ||
369 | * refcount released by caller | ||
370 | */ | ||
371 | struct aa_namespace *aa_find_namespace(struct aa_namespace *root, | ||
372 | const char *name) | ||
373 | { | ||
374 | struct aa_namespace *ns = NULL; | ||
375 | |||
376 | read_lock(&root->lock); | ||
377 | ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name)); | ||
378 | read_unlock(&root->lock); | ||
379 | |||
380 | return ns; | ||
381 | } | ||
382 | |||
383 | /** | ||
384 | * aa_prepare_namespace - find an existing or create a new namespace of @name | ||
385 | * @name: the namespace to find or add (MAYBE NULL) | ||
386 | * | ||
387 | * Returns: refcounted namespace or NULL if failed to create one | ||
388 | */ | ||
389 | static struct aa_namespace *aa_prepare_namespace(const char *name) | ||
390 | { | ||
391 | struct aa_namespace *ns, *root; | ||
392 | |||
393 | root = aa_current_profile()->ns; | ||
394 | |||
395 | write_lock(&root->lock); | ||
396 | |||
397 | /* if name isn't specified the profile is loaded to the current ns */ | ||
398 | if (!name) { | ||
399 | /* released by caller */ | ||
400 | ns = aa_get_namespace(root); | ||
401 | goto out; | ||
402 | } | ||
403 | |||
404 | /* try and find the specified ns and if it doesn't exist create it */ | ||
405 | /* released by caller */ | ||
406 | ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name)); | ||
407 | if (!ns) { | ||
408 | /* namespace not found */ | ||
409 | struct aa_namespace *new_ns; | ||
410 | write_unlock(&root->lock); | ||
411 | new_ns = alloc_namespace(root->base.hname, name); | ||
412 | if (!new_ns) | ||
413 | return NULL; | ||
414 | write_lock(&root->lock); | ||
415 | /* test for race when new_ns was allocated */ | ||
416 | ns = __aa_find_namespace(&root->sub_ns, name); | ||
417 | if (!ns) { | ||
418 | /* add parent ref */ | ||
419 | new_ns->parent = aa_get_namespace(root); | ||
420 | |||
421 | list_add(&new_ns->base.list, &root->sub_ns); | ||
422 | /* add list ref */ | ||
423 | ns = aa_get_namespace(new_ns); | ||
424 | } else { | ||
425 | /* raced so free the new one */ | ||
426 | free_namespace(new_ns); | ||
427 | /* get reference on namespace */ | ||
428 | aa_get_namespace(ns); | ||
429 | } | ||
430 | } | ||
431 | out: | ||
432 | write_unlock(&root->lock); | ||
433 | |||
434 | /* return ref */ | ||
435 | return ns; | ||
436 | } | ||
437 | |||
438 | /** | ||
439 | * __list_add_profile - add a profile to a list | ||
440 | * @list: list to add it to (NOT NULL) | ||
441 | * @profile: the profile to add (NOT NULL) | ||
442 | * | ||
443 | * refcount @profile, should be put by __list_remove_profile | ||
444 | * | ||
445 | * Requires: namespace lock be held, or list not be shared | ||
446 | */ | ||
447 | static void __list_add_profile(struct list_head *list, | ||
448 | struct aa_profile *profile) | ||
449 | { | ||
450 | list_add(&profile->base.list, list); | ||
451 | /* get list reference */ | ||
452 | aa_get_profile(profile); | ||
453 | } | ||
454 | |||
455 | /** | ||
456 | * __list_remove_profile - remove a profile from the list it is on | ||
457 | * @profile: the profile to remove (NOT NULL) | ||
458 | * | ||
459 | * remove a profile from the list, warning generally removal should | ||
460 | * be done with __replace_profile as most profile removals are | ||
461 | * replacements to the unconfined profile. | ||
462 | * | ||
463 | * put @profile list refcount | ||
464 | * | ||
465 | * Requires: namespace lock be held, or list not have been live | ||
466 | */ | ||
467 | static void __list_remove_profile(struct aa_profile *profile) | ||
468 | { | ||
469 | list_del_init(&profile->base.list); | ||
470 | if (!(profile->flags & PFLAG_NO_LIST_REF)) | ||
471 | /* release list reference */ | ||
472 | aa_put_profile(profile); | ||
473 | } | ||
474 | |||
475 | /** | ||
476 | * __replace_profile - replace @old with @new on a list | ||
477 | * @old: profile to be replaced (NOT NULL) | ||
478 | * @new: profile to replace @old with (NOT NULL) | ||
479 | * | ||
480 | * Will duplicate and refcount elements that @new inherits from @old | ||
481 | * and will inherit @old children. | ||
482 | * | ||
483 | * refcount @new for list, put @old list refcount | ||
484 | * | ||
485 | * Requires: namespace list lock be held, or list not be shared | ||
486 | */ | ||
487 | static void __replace_profile(struct aa_profile *old, struct aa_profile *new) | ||
488 | { | ||
489 | struct aa_policy *policy; | ||
490 | struct aa_profile *child, *tmp; | ||
491 | |||
492 | if (old->parent) | ||
493 | policy = &old->parent->base; | ||
494 | else | ||
495 | policy = &old->ns->base; | ||
496 | |||
497 | /* released when @new is freed */ | ||
498 | new->parent = aa_get_profile(old->parent); | ||
499 | new->ns = aa_get_namespace(old->ns); | ||
500 | new->sid = old->sid; | ||
501 | __list_add_profile(&policy->profiles, new); | ||
502 | /* inherit children */ | ||
503 | list_for_each_entry_safe(child, tmp, &old->base.profiles, base.list) { | ||
504 | aa_put_profile(child->parent); | ||
505 | child->parent = aa_get_profile(new); | ||
506 | /* list refcount transferred to @new*/ | ||
507 | list_move(&child->base.list, &new->base.profiles); | ||
508 | } | ||
509 | |||
510 | /* released by free_profile */ | ||
511 | old->replacedby = aa_get_profile(new); | ||
512 | __list_remove_profile(old); | ||
513 | } | ||
514 | |||
515 | static void __profile_list_release(struct list_head *head); | ||
516 | |||
517 | /** | ||
518 | * __remove_profile - remove old profile, and children | ||
519 | * @profile: profile to be replaced (NOT NULL) | ||
520 | * | ||
521 | * Requires: namespace list lock be held, or list not be shared | ||
522 | */ | ||
523 | static void __remove_profile(struct aa_profile *profile) | ||
524 | { | ||
525 | /* release any children lists first */ | ||
526 | __profile_list_release(&profile->base.profiles); | ||
527 | /* released by free_profile */ | ||
528 | profile->replacedby = aa_get_profile(profile->ns->unconfined); | ||
529 | __list_remove_profile(profile); | ||
530 | } | ||
531 | |||
532 | /** | ||
533 | * __profile_list_release - remove all profiles on the list and put refs | ||
534 | * @head: list of profiles (NOT NULL) | ||
535 | * | ||
536 | * Requires: namespace lock be held | ||
537 | */ | ||
538 | static void __profile_list_release(struct list_head *head) | ||
539 | { | ||
540 | struct aa_profile *profile, *tmp; | ||
541 | list_for_each_entry_safe(profile, tmp, head, base.list) | ||
542 | __remove_profile(profile); | ||
543 | } | ||
544 | |||
545 | static void __ns_list_release(struct list_head *head); | ||
546 | |||
547 | /** | ||
548 | * destroy_namespace - remove everything contained by @ns | ||
549 | * @ns: namespace to have it contents removed (NOT NULL) | ||
550 | */ | ||
551 | static void destroy_namespace(struct aa_namespace *ns) | ||
552 | { | ||
553 | if (!ns) | ||
554 | return; | ||
555 | |||
556 | write_lock(&ns->lock); | ||
557 | /* release all profiles in this namespace */ | ||
558 | __profile_list_release(&ns->base.profiles); | ||
559 | |||
560 | /* release all sub namespaces */ | ||
561 | __ns_list_release(&ns->sub_ns); | ||
562 | |||
563 | write_unlock(&ns->lock); | ||
564 | } | ||
565 | |||
566 | /** | ||
567 | * __remove_namespace - remove a namespace and all its children | ||
568 | * @ns: namespace to be removed (NOT NULL) | ||
569 | * | ||
570 | * Requires: ns->parent->lock be held and ns removed from parent. | ||
571 | */ | ||
572 | static void __remove_namespace(struct aa_namespace *ns) | ||
573 | { | ||
574 | struct aa_profile *unconfined = ns->unconfined; | ||
575 | |||
576 | /* remove ns from namespace list */ | ||
577 | list_del_init(&ns->base.list); | ||
578 | |||
579 | /* | ||
580 | * break the ns, unconfined profile cyclic reference and forward | ||
581 | * all new unconfined profiles requests to the parent namespace | ||
582 | * This will result in all confined tasks that have a profile | ||
583 | * being removed, inheriting the parent->unconfined profile. | ||
584 | */ | ||
585 | if (ns->parent) | ||
586 | ns->unconfined = aa_get_profile(ns->parent->unconfined); | ||
587 | |||
588 | destroy_namespace(ns); | ||
589 | |||
590 | /* release original ns->unconfined ref */ | ||
591 | aa_put_profile(unconfined); | ||
592 | /* release ns->base.list ref, from removal above */ | ||
593 | aa_put_namespace(ns); | ||
594 | } | ||
595 | |||
596 | /** | ||
597 | * __ns_list_release - remove all profile namespaces on the list put refs | ||
598 | * @head: list of profile namespaces (NOT NULL) | ||
599 | * | ||
600 | * Requires: namespace lock be held | ||
601 | */ | ||
602 | static void __ns_list_release(struct list_head *head) | ||
603 | { | ||
604 | struct aa_namespace *ns, *tmp; | ||
605 | list_for_each_entry_safe(ns, tmp, head, base.list) | ||
606 | __remove_namespace(ns); | ||
607 | |||
608 | } | ||
609 | |||
610 | /** | ||
611 | * aa_alloc_root_ns - allocate the root profile namespace | ||
612 | * | ||
613 | * Returns: %0 on success else error | ||
614 | * | ||
615 | */ | ||
616 | int __init aa_alloc_root_ns(void) | ||
617 | { | ||
618 | /* released by aa_free_root_ns - used as list ref*/ | ||
619 | root_ns = alloc_namespace(NULL, "root"); | ||
620 | if (!root_ns) | ||
621 | return -ENOMEM; | ||
622 | |||
623 | return 0; | ||
624 | } | ||
625 | |||
626 | /** | ||
627 | * aa_free_root_ns - free the root profile namespace | ||
628 | */ | ||
629 | void __init aa_free_root_ns(void) | ||
630 | { | ||
631 | struct aa_namespace *ns = root_ns; | ||
632 | root_ns = NULL; | ||
633 | |||
634 | destroy_namespace(ns); | ||
635 | aa_put_namespace(ns); | ||
636 | } | ||
637 | |||
638 | /** | ||
639 | * aa_alloc_profile - allocate, initialize and return a new profile | ||
640 | * @hname: name of the profile (NOT NULL) | ||
641 | * | ||
642 | * Returns: refcount profile or NULL on failure | ||
643 | */ | ||
644 | struct aa_profile *aa_alloc_profile(const char *hname) | ||
645 | { | ||
646 | struct aa_profile *profile; | ||
647 | |||
648 | /* freed by free_profile - usually through aa_put_profile */ | ||
649 | profile = kzalloc(sizeof(*profile), GFP_KERNEL); | ||
650 | if (!profile) | ||
651 | return NULL; | ||
652 | |||
653 | if (!policy_init(&profile->base, NULL, hname)) { | ||
654 | kzfree(profile); | ||
655 | return NULL; | ||
656 | } | ||
657 | |||
658 | /* refcount released by caller */ | ||
659 | return profile; | ||
660 | } | ||
661 | |||
662 | /** | ||
663 | * aa_new_null_profile - create a new null-X learning profile | ||
664 | * @parent: profile that caused this profile to be created (NOT NULL) | ||
665 | * @hat: true if the null- learning profile is a hat | ||
666 | * | ||
667 | * Create a null- complain mode profile used in learning mode. The name of | ||
668 | * the profile is unique and follows the format of parent//null-sid. | ||
669 | * | ||
670 | * null profiles are added to the profile list but the list does not | ||
671 | * hold a count on them so that they are automatically released when | ||
672 | * not in use. | ||
673 | * | ||
674 | * Returns: new refcounted profile else NULL on failure | ||
675 | */ | ||
676 | struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat) | ||
677 | { | ||
678 | struct aa_profile *profile = NULL; | ||
679 | char *name; | ||
680 | u32 sid = aa_alloc_sid(); | ||
681 | |||
682 | /* freed below */ | ||
683 | name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL); | ||
684 | if (!name) | ||
685 | goto fail; | ||
686 | sprintf(name, "%s//null-%x", parent->base.hname, sid); | ||
687 | |||
688 | profile = aa_alloc_profile(name); | ||
689 | kfree(name); | ||
690 | if (!profile) | ||
691 | goto fail; | ||
692 | |||
693 | profile->sid = sid; | ||
694 | profile->mode = APPARMOR_COMPLAIN; | ||
695 | profile->flags = PFLAG_NULL; | ||
696 | if (hat) | ||
697 | profile->flags |= PFLAG_HAT; | ||
698 | |||
699 | /* released on free_profile */ | ||
700 | profile->parent = aa_get_profile(parent); | ||
701 | profile->ns = aa_get_namespace(parent->ns); | ||
702 | |||
703 | write_lock(&profile->ns->lock); | ||
704 | __list_add_profile(&parent->base.profiles, profile); | ||
705 | write_unlock(&profile->ns->lock); | ||
706 | |||
707 | /* refcount released by caller */ | ||
708 | return profile; | ||
709 | |||
710 | fail: | ||
711 | aa_free_sid(sid); | ||
712 | return NULL; | ||
713 | } | ||
714 | |||
715 | /** | ||
716 | * free_profile - free a profile | ||
717 | * @profile: the profile to free (MAYBE NULL) | ||
718 | * | ||
719 | * Free a profile, its hats and null_profile. All references to the profile, | ||
720 | * its hats and null_profile must have been put. | ||
721 | * | ||
722 | * If the profile was referenced from a task context, free_profile() will | ||
723 | * be called from an rcu callback routine, so we must not sleep here. | ||
724 | */ | ||
725 | static void free_profile(struct aa_profile *profile) | ||
726 | { | ||
727 | AA_DEBUG("%s(%p)\n", __func__, profile); | ||
728 | |||
729 | if (!profile) | ||
730 | return; | ||
731 | |||
732 | if (!list_empty(&profile->base.list)) { | ||
733 | AA_ERROR("%s: internal error, " | ||
734 | "profile '%s' still on ns list\n", | ||
735 | __func__, profile->base.name); | ||
736 | BUG(); | ||
737 | } | ||
738 | |||
739 | /* free children profiles */ | ||
740 | policy_destroy(&profile->base); | ||
741 | aa_put_profile(profile->parent); | ||
742 | |||
743 | aa_put_namespace(profile->ns); | ||
744 | kzfree(profile->rename); | ||
745 | |||
746 | aa_free_file_rules(&profile->file); | ||
747 | aa_free_cap_rules(&profile->caps); | ||
748 | aa_free_rlimit_rules(&profile->rlimits); | ||
749 | |||
750 | aa_free_sid(profile->sid); | ||
751 | aa_put_dfa(profile->xmatch); | ||
752 | |||
753 | aa_put_profile(profile->replacedby); | ||
754 | |||
755 | kzfree(profile); | ||
756 | } | ||
757 | |||
758 | /** | ||
759 | * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile) | ||
760 | * @kr: kref callback for freeing of a profile (NOT NULL) | ||
761 | */ | ||
762 | void aa_free_profile_kref(struct kref *kref) | ||
763 | { | ||
764 | struct aa_profile *p = container_of(kref, struct aa_profile, | ||
765 | base.count); | ||
766 | |||
767 | free_profile(p); | ||
768 | } | ||
769 | |||
770 | /* TODO: profile accounting - setup in remove */ | ||
771 | |||
772 | /** | ||
773 | * __find_child - find a profile on @head list with a name matching @name | ||
774 | * @head: list to search (NOT NULL) | ||
775 | * @name: name of profile (NOT NULL) | ||
776 | * | ||
777 | * Requires: ns lock protecting list be held | ||
778 | * | ||
779 | * Returns: unrefcounted profile ptr, or NULL if not found | ||
780 | */ | ||
781 | static struct aa_profile *__find_child(struct list_head *head, const char *name) | ||
782 | { | ||
783 | return (struct aa_profile *)__policy_find(head, name); | ||
784 | } | ||
785 | |||
786 | /** | ||
787 | * __strn_find_child - find a profile on @head list using substring of @name | ||
788 | * @head: list to search (NOT NULL) | ||
789 | * @name: name of profile (NOT NULL) | ||
790 | * @len: length of @name substring to match | ||
791 | * | ||
792 | * Requires: ns lock protecting list be held | ||
793 | * | ||
794 | * Returns: unrefcounted profile ptr, or NULL if not found | ||
795 | */ | ||
796 | static struct aa_profile *__strn_find_child(struct list_head *head, | ||
797 | const char *name, int len) | ||
798 | { | ||
799 | return (struct aa_profile *)__policy_strn_find(head, name, len); | ||
800 | } | ||
801 | |||
802 | /** | ||
803 | * aa_find_child - find a profile by @name in @parent | ||
804 | * @parent: profile to search (NOT NULL) | ||
805 | * @name: profile name to search for (NOT NULL) | ||
806 | * | ||
807 | * Returns: a refcounted profile or NULL if not found | ||
808 | */ | ||
809 | struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name) | ||
810 | { | ||
811 | struct aa_profile *profile; | ||
812 | |||
813 | read_lock(&parent->ns->lock); | ||
814 | profile = aa_get_profile(__find_child(&parent->base.profiles, name)); | ||
815 | read_unlock(&parent->ns->lock); | ||
816 | |||
817 | /* refcount released by caller */ | ||
818 | return profile; | ||
819 | } | ||
820 | |||
821 | /** | ||
822 | * __lookup_parent - lookup the parent of a profile of name @hname | ||
823 | * @ns: namespace to lookup profile in (NOT NULL) | ||
824 | * @hname: hierarchical profile name to find parent of (NOT NULL) | ||
825 | * | ||
826 | * Lookups up the parent of a fully qualified profile name, the profile | ||
827 | * that matches hname does not need to exist, in general this | ||
828 | * is used to load a new profile. | ||
829 | * | ||
830 | * Requires: ns->lock be held | ||
831 | * | ||
832 | * Returns: unrefcounted policy or NULL if not found | ||
833 | */ | ||
834 | static struct aa_policy *__lookup_parent(struct aa_namespace *ns, | ||
835 | const char *hname) | ||
836 | { | ||
837 | struct aa_policy *policy; | ||
838 | struct aa_profile *profile = NULL; | ||
839 | char *split; | ||
840 | |||
841 | policy = &ns->base; | ||
842 | |||
843 | for (split = strstr(hname, "//"); split;) { | ||
844 | profile = __strn_find_child(&policy->profiles, hname, | ||
845 | split - hname); | ||
846 | if (!profile) | ||
847 | return NULL; | ||
848 | policy = &profile->base; | ||
849 | hname = split + 2; | ||
850 | split = strstr(hname, "//"); | ||
851 | } | ||
852 | if (!profile) | ||
853 | return &ns->base; | ||
854 | return &profile->base; | ||
855 | } | ||
856 | |||
857 | /** | ||
858 | * __lookup_profile - lookup the profile matching @hname | ||
859 | * @base: base list to start looking up profile name from (NOT NULL) | ||
860 | * @hname: hierarchical profile name (NOT NULL) | ||
861 | * | ||
862 | * Requires: ns->lock be held | ||
863 | * | ||
864 | * Returns: unrefcounted profile pointer or NULL if not found | ||
865 | * | ||
866 | * Do a relative name lookup, recursing through profile tree. | ||
867 | */ | ||
868 | static struct aa_profile *__lookup_profile(struct aa_policy *base, | ||
869 | const char *hname) | ||
870 | { | ||
871 | struct aa_profile *profile = NULL; | ||
872 | char *split; | ||
873 | |||
874 | for (split = strstr(hname, "//"); split;) { | ||
875 | profile = __strn_find_child(&base->profiles, hname, | ||
876 | split - hname); | ||
877 | if (!profile) | ||
878 | return NULL; | ||
879 | |||
880 | base = &profile->base; | ||
881 | hname = split + 2; | ||
882 | split = strstr(hname, "//"); | ||
883 | } | ||
884 | |||
885 | profile = __find_child(&base->profiles, hname); | ||
886 | |||
887 | return profile; | ||
888 | } | ||
889 | |||
890 | /** | ||
891 | * aa_lookup_profile - find a profile by its full or partial name | ||
892 | * @ns: the namespace to start from (NOT NULL) | ||
893 | * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL) | ||
894 | * | ||
895 | * Returns: refcounted profile or NULL if not found | ||
896 | */ | ||
897 | struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname) | ||
898 | { | ||
899 | struct aa_profile *profile; | ||
900 | |||
901 | read_lock(&ns->lock); | ||
902 | profile = aa_get_profile(__lookup_profile(&ns->base, hname)); | ||
903 | read_unlock(&ns->lock); | ||
904 | |||
905 | /* refcount released by caller */ | ||
906 | return profile; | ||
907 | } | ||
908 | |||
909 | /** | ||
910 | * replacement_allowed - test to see if replacement is allowed | ||
911 | * @profile: profile to test if it can be replaced (MAYBE NULL) | ||
912 | * @noreplace: true if replacement shouldn't be allowed but addition is okay | ||
913 | * @info: Returns - info about why replacement failed (NOT NULL) | ||
914 | * | ||
915 | * Returns: %0 if replacement allowed else error code | ||
916 | */ | ||
917 | static int replacement_allowed(struct aa_profile *profile, int noreplace, | ||
918 | const char **info) | ||
919 | { | ||
920 | if (profile) { | ||
921 | if (profile->flags & PFLAG_IMMUTABLE) { | ||
922 | *info = "cannot replace immutible profile"; | ||
923 | return -EPERM; | ||
924 | } else if (noreplace) { | ||
925 | *info = "profile already exists"; | ||
926 | return -EEXIST; | ||
927 | } | ||
928 | } | ||
929 | return 0; | ||
930 | } | ||
931 | |||
932 | /** | ||
933 | * __add_new_profile - simple wrapper around __list_add_profile | ||
934 | * @ns: namespace that profile is being added to (NOT NULL) | ||
935 | * @policy: the policy container to add the profile to (NOT NULL) | ||
936 | * @profile: profile to add (NOT NULL) | ||
937 | * | ||
938 | * add a profile to a list and do other required basic allocations | ||
939 | */ | ||
940 | static void __add_new_profile(struct aa_namespace *ns, struct aa_policy *policy, | ||
941 | struct aa_profile *profile) | ||
942 | { | ||
943 | if (policy != &ns->base) | ||
944 | /* released on profile replacement or free_profile */ | ||
945 | profile->parent = aa_get_profile((struct aa_profile *) policy); | ||
946 | __list_add_profile(&policy->profiles, profile); | ||
947 | /* released on free_profile */ | ||
948 | profile->sid = aa_alloc_sid(); | ||
949 | profile->ns = aa_get_namespace(ns); | ||
950 | } | ||
951 | |||
952 | /** | ||
953 | * aa_audit_policy - Do auditing of policy changes | ||
954 | * @op: policy operation being performed | ||
955 | * @gfp: memory allocation flags | ||
956 | * @name: name of profile being manipulated (NOT NULL) | ||
957 | * @info: any extra information to be audited (MAYBE NULL) | ||
958 | * @error: error code | ||
959 | * | ||
960 | * Returns: the error to be returned after audit is done | ||
961 | */ | ||
962 | static int audit_policy(int op, gfp_t gfp, const char *name, const char *info, | ||
963 | int error) | ||
964 | { | ||
965 | struct common_audit_data sa; | ||
966 | COMMON_AUDIT_DATA_INIT(&sa, NONE); | ||
967 | sa.aad.op = op; | ||
968 | sa.aad.name = name; | ||
969 | sa.aad.info = info; | ||
970 | sa.aad.error = error; | ||
971 | |||
972 | return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp, | ||
973 | &sa, NULL); | ||
974 | } | ||
975 | |||
976 | /** | ||
977 | * aa_may_manage_policy - can the current task manage policy | ||
978 | * @op: the policy manipulation operation being done | ||
979 | * | ||
980 | * Returns: true if the task is allowed to manipulate policy | ||
981 | */ | ||
982 | bool aa_may_manage_policy(int op) | ||
983 | { | ||
984 | /* check if loading policy is locked out */ | ||
985 | if (aa_g_lock_policy) { | ||
986 | audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES); | ||
987 | return 0; | ||
988 | } | ||
989 | |||
990 | if (!capable(CAP_MAC_ADMIN)) { | ||
991 | audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES); | ||
992 | return 0; | ||
993 | } | ||
994 | |||
995 | return 1; | ||
996 | } | ||
997 | |||
998 | /** | ||
999 | * aa_replace_profiles - replace profile(s) on the profile list | ||
1000 | * @udata: serialized data stream (NOT NULL) | ||
1001 | * @size: size of the serialized data stream | ||
1002 | * @noreplace: true if only doing addition, no replacement allowed | ||
1003 | * | ||
1004 | * unpack and replace a profile on the profile list and uses of that profile | ||
1005 | * by any aa_task_cxt. If the profile does not exist on the profile list | ||
1006 | * it is added. | ||
1007 | * | ||
1008 | * Returns: size of data consumed else error code on failure. | ||
1009 | */ | ||
1010 | ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace) | ||
1011 | { | ||
1012 | struct aa_policy *policy; | ||
1013 | struct aa_profile *old_profile = NULL, *new_profile = NULL; | ||
1014 | struct aa_profile *rename_profile = NULL; | ||
1015 | struct aa_namespace *ns = NULL; | ||
1016 | const char *ns_name, *name = NULL, *info = NULL; | ||
1017 | int op = OP_PROF_REPL; | ||
1018 | ssize_t error; | ||
1019 | |||
1020 | /* released below */ | ||
1021 | new_profile = aa_unpack(udata, size, &ns_name); | ||
1022 | if (IS_ERR(new_profile)) { | ||
1023 | error = PTR_ERR(new_profile); | ||
1024 | new_profile = NULL; | ||
1025 | goto fail; | ||
1026 | } | ||
1027 | |||
1028 | /* released below */ | ||
1029 | ns = aa_prepare_namespace(ns_name); | ||
1030 | if (!ns) { | ||
1031 | info = "failed to prepare namespace"; | ||
1032 | error = -ENOMEM; | ||
1033 | name = ns_name; | ||
1034 | goto fail; | ||
1035 | } | ||
1036 | |||
1037 | name = new_profile->base.hname; | ||
1038 | |||
1039 | write_lock(&ns->lock); | ||
1040 | /* no ref on policy only use inside lock */ | ||
1041 | policy = __lookup_parent(ns, new_profile->base.hname); | ||
1042 | |||
1043 | if (!policy) { | ||
1044 | info = "parent does not exist"; | ||
1045 | error = -ENOENT; | ||
1046 | goto audit; | ||
1047 | } | ||
1048 | |||
1049 | old_profile = __find_child(&policy->profiles, new_profile->base.name); | ||
1050 | /* released below */ | ||
1051 | aa_get_profile(old_profile); | ||
1052 | |||
1053 | if (new_profile->rename) { | ||
1054 | rename_profile = __lookup_profile(&ns->base, | ||
1055 | new_profile->rename); | ||
1056 | /* released below */ | ||
1057 | aa_get_profile(rename_profile); | ||
1058 | |||
1059 | if (!rename_profile) { | ||
1060 | info = "profile to rename does not exist"; | ||
1061 | name = new_profile->rename; | ||
1062 | error = -ENOENT; | ||
1063 | goto audit; | ||
1064 | } | ||
1065 | } | ||
1066 | |||
1067 | error = replacement_allowed(old_profile, noreplace, &info); | ||
1068 | if (error) | ||
1069 | goto audit; | ||
1070 | |||
1071 | error = replacement_allowed(rename_profile, noreplace, &info); | ||
1072 | if (error) | ||
1073 | goto audit; | ||
1074 | |||
1075 | audit: | ||
1076 | if (!old_profile && !rename_profile) | ||
1077 | op = OP_PROF_LOAD; | ||
1078 | |||
1079 | error = audit_policy(op, GFP_ATOMIC, name, info, error); | ||
1080 | |||
1081 | if (!error) { | ||
1082 | if (rename_profile) | ||
1083 | __replace_profile(rename_profile, new_profile); | ||
1084 | if (old_profile) { | ||
1085 | /* when there are both rename and old profiles | ||
1086 | * inherit old profiles sid | ||
1087 | */ | ||
1088 | if (rename_profile) | ||
1089 | aa_free_sid(new_profile->sid); | ||
1090 | __replace_profile(old_profile, new_profile); | ||
1091 | } | ||
1092 | if (!(old_profile || rename_profile)) | ||
1093 | __add_new_profile(ns, policy, new_profile); | ||
1094 | } | ||
1095 | write_unlock(&ns->lock); | ||
1096 | |||
1097 | out: | ||
1098 | aa_put_namespace(ns); | ||
1099 | aa_put_profile(rename_profile); | ||
1100 | aa_put_profile(old_profile); | ||
1101 | aa_put_profile(new_profile); | ||
1102 | if (error) | ||
1103 | return error; | ||
1104 | return size; | ||
1105 | |||
1106 | fail: | ||
1107 | error = audit_policy(op, GFP_KERNEL, name, info, error); | ||
1108 | goto out; | ||
1109 | } | ||
1110 | |||
1111 | /** | ||
1112 | * aa_remove_profiles - remove profile(s) from the system | ||
1113 | * @fqname: name of the profile or namespace to remove (NOT NULL) | ||
1114 | * @size: size of the name | ||
1115 | * | ||
1116 | * Remove a profile or sub namespace from the current namespace, so that | ||
1117 | * they can not be found anymore and mark them as replaced by unconfined | ||
1118 | * | ||
1119 | * NOTE: removing confinement does not restore rlimits to preconfinemnet values | ||
1120 | * | ||
1121 | * Returns: size of data consume else error code if fails | ||
1122 | */ | ||
1123 | ssize_t aa_remove_profiles(char *fqname, size_t size) | ||
1124 | { | ||
1125 | struct aa_namespace *root, *ns = NULL; | ||
1126 | struct aa_profile *profile = NULL; | ||
1127 | const char *name = fqname, *info = NULL; | ||
1128 | ssize_t error = 0; | ||
1129 | |||
1130 | if (*fqname == 0) { | ||
1131 | info = "no profile specified"; | ||
1132 | error = -ENOENT; | ||
1133 | goto fail; | ||
1134 | } | ||
1135 | |||
1136 | root = aa_current_profile()->ns; | ||
1137 | |||
1138 | if (fqname[0] == ':') { | ||
1139 | char *ns_name; | ||
1140 | name = aa_split_fqname(fqname, &ns_name); | ||
1141 | if (ns_name) { | ||
1142 | /* released below */ | ||
1143 | ns = aa_find_namespace(root, ns_name); | ||
1144 | if (!ns) { | ||
1145 | info = "namespace does not exist"; | ||
1146 | error = -ENOENT; | ||
1147 | goto fail; | ||
1148 | } | ||
1149 | } | ||
1150 | } else | ||
1151 | /* released below */ | ||
1152 | ns = aa_get_namespace(root); | ||
1153 | |||
1154 | write_lock(&ns->lock); | ||
1155 | if (!name) { | ||
1156 | /* remove namespace - can only happen if fqname[0] == ':' */ | ||
1157 | __remove_namespace(ns); | ||
1158 | } else { | ||
1159 | /* remove profile */ | ||
1160 | profile = aa_get_profile(__lookup_profile(&ns->base, name)); | ||
1161 | if (!profile) { | ||
1162 | error = -ENOENT; | ||
1163 | info = "profile does not exist"; | ||
1164 | goto fail_ns_lock; | ||
1165 | } | ||
1166 | name = profile->base.hname; | ||
1167 | __remove_profile(profile); | ||
1168 | } | ||
1169 | write_unlock(&ns->lock); | ||
1170 | |||
1171 | /* don't fail removal if audit fails */ | ||
1172 | (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error); | ||
1173 | aa_put_namespace(ns); | ||
1174 | aa_put_profile(profile); | ||
1175 | return size; | ||
1176 | |||
1177 | fail_ns_lock: | ||
1178 | write_unlock(&ns->lock); | ||
1179 | aa_put_namespace(ns); | ||
1180 | |||
1181 | fail: | ||
1182 | (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error); | ||
1183 | return error; | ||
1184 | } | ||
diff --git a/security/apparmor/sid.c b/security/apparmor/sid.c new file mode 100644 index 000000000000..f0b34f76ebef --- /dev/null +++ b/security/apparmor/sid.c | |||
@@ -0,0 +1,55 @@ | |||
1 | /* | ||
2 | * AppArmor security module | ||
3 | * | ||
4 | * This file contains AppArmor security identifier (sid) manipulation fns | ||
5 | * | ||
6 | * Copyright 2009-2010 Canonical Ltd. | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or | ||
9 | * modify it under the terms of the GNU General Public License as | ||
10 | * published by the Free Software Foundation, version 2 of the | ||
11 | * License. | ||
12 | * | ||
13 | * | ||
14 | * AppArmor allocates a unique sid for every profile loaded. If a profile | ||
15 | * is replaced it receives the sid of the profile it is replacing. | ||
16 | * | ||
17 | * The sid value of 0 is invalid. | ||
18 | */ | ||
19 | |||
20 | #include <linux/spinlock.h> | ||
21 | #include <linux/errno.h> | ||
22 | #include <linux/err.h> | ||
23 | |||
24 | #include "include/sid.h" | ||
25 | |||
26 | /* global counter from which sids are allocated */ | ||
27 | static u32 global_sid; | ||
28 | static DEFINE_SPINLOCK(sid_lock); | ||
29 | |||
30 | /* TODO FIXME: add sid to profile mapping, and sid recycling */ | ||
31 | |||
32 | /** | ||
33 | * aa_alloc_sid - allocate a new sid for a profile | ||
34 | */ | ||
35 | u32 aa_alloc_sid(void) | ||
36 | { | ||
37 | u32 sid; | ||
38 | |||
39 | /* | ||
40 | * TODO FIXME: sid recycling - part of profile mapping table | ||
41 | */ | ||
42 | spin_lock(&sid_lock); | ||
43 | sid = (++global_sid); | ||
44 | spin_unlock(&sid_lock); | ||
45 | return sid; | ||
46 | } | ||
47 | |||
48 | /** | ||
49 | * aa_free_sid - free a sid | ||
50 | * @sid: sid to free | ||
51 | */ | ||
52 | void aa_free_sid(u32 sid) | ||
53 | { | ||
54 | ; /* NOP ATM */ | ||
55 | } | ||