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David Howells973c9f42011-01-20 16:38:33 +00001/* Userspace key control operations
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David Howells3e301482005-06-23 22:00:56 -07003 * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/sched.h>
15#include <linux/slab.h>
16#include <linux/syscalls.h>
17#include <linux/keyctl.h>
18#include <linux/fs.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080019#include <linux/capability.h>
Davi Arnaut0cb409d2006-03-24 03:18:43 -080020#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/err.h>
David Howells38bbca62008-04-29 01:01:19 -070022#include <linux/vmalloc.h>
David Howells70a5bb72008-04-29 01:01:26 -070023#include <linux/security.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/uaccess.h>
25#include "internal.h"
26
Davi Arnaut0cb409d2006-03-24 03:18:43 -080027static int key_get_type_from_user(char *type,
28 const char __user *_type,
29 unsigned len)
30{
31 int ret;
32
33 ret = strncpy_from_user(type, _type, len);
Davi Arnaut0cb409d2006-03-24 03:18:43 -080034 if (ret < 0)
Dan Carpenter4303ef12010-06-11 17:30:05 +010035 return ret;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080036 if (ret == 0 || ret >= len)
37 return -EINVAL;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080038 if (type[0] == '.')
39 return -EPERM;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080040 type[len - 1] = '\0';
Davi Arnaut0cb409d2006-03-24 03:18:43 -080041 return 0;
42}
43
Linus Torvalds1da177e2005-04-16 15:20:36 -070044/*
David Howells973c9f42011-01-20 16:38:33 +000045 * Extract the description of a new key from userspace and either add it as a
46 * new key to the specified keyring or update a matching key in that keyring.
47 *
48 * The keyring must be writable so that we can attach the key to it.
49 *
50 * If successful, the new key's serial number is returned, otherwise an error
51 * code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +010053SYSCALL_DEFINE5(add_key, const char __user *, _type,
54 const char __user *, _description,
55 const void __user *, _payload,
56 size_t, plen,
57 key_serial_t, ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
David Howells664cceb2005-09-28 17:03:15 +010059 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 char type[32], *description;
61 void *payload;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080062 long ret;
David Howells38bbca62008-04-29 01:01:19 -070063 bool vm;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -070066 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 goto error;
68
69 /* draw all the data into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -080070 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 if (ret < 0)
72 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Davi Arnaut0cb409d2006-03-24 03:18:43 -080074 description = strndup_user(_description, PAGE_SIZE);
75 if (IS_ERR(description)) {
76 ret = PTR_ERR(description);
David Howells3e301482005-06-23 22:00:56 -070077 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080078 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80 /* pull the payload in if one was supplied */
81 payload = NULL;
82
David Howells38bbca62008-04-29 01:01:19 -070083 vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 if (_payload) {
85 ret = -ENOMEM;
86 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -070087 if (!payload) {
88 if (plen <= PAGE_SIZE)
89 goto error2;
90 vm = true;
91 payload = vmalloc(plen);
92 if (!payload)
93 goto error2;
94 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 ret = -EFAULT;
97 if (copy_from_user(payload, _payload, plen) != 0)
98 goto error3;
99 }
100
101 /* find the target keyring (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100102 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100103 if (IS_ERR(keyring_ref)) {
104 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 goto error3;
106 }
107
108 /* create or update the requested key and add it to the target
109 * keyring */
David Howells664cceb2005-09-28 17:03:15 +0100110 key_ref = key_create_or_update(keyring_ref, type, description,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700111 payload, plen, KEY_PERM_UNDEF,
112 KEY_ALLOC_IN_QUOTA);
David Howells664cceb2005-09-28 17:03:15 +0100113 if (!IS_ERR(key_ref)) {
114 ret = key_ref_to_ptr(key_ref)->serial;
115 key_ref_put(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 }
117 else {
David Howells664cceb2005-09-28 17:03:15 +0100118 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 }
120
David Howells664cceb2005-09-28 17:03:15 +0100121 key_ref_put(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 error3:
David Howells38bbca62008-04-29 01:01:19 -0700123 if (!vm)
124 kfree(payload);
125 else
126 vfree(payload);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 error2:
128 kfree(description);
129 error:
130 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133/*
David Howells973c9f42011-01-20 16:38:33 +0000134 * Search the process keyrings and keyring trees linked from those for a
135 * matching key. Keyrings must have appropriate Search permission to be
136 * searched.
137 *
138 * If a key is found, it will be attached to the destination keyring if there's
139 * one specified and the serial number of the key will be returned.
140 *
141 * If no key is found, /sbin/request-key will be invoked if _callout_info is
142 * non-NULL in an attempt to create a key. The _callout_info string will be
143 * passed to /sbin/request-key to aid with completing the request. If the
144 * _callout_info string is "" then it will be changed to "-".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +0100146SYSCALL_DEFINE4(request_key, const char __user *, _type,
147 const char __user *, _description,
148 const char __user *, _callout_info,
149 key_serial_t, destringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
151 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100152 struct key *key;
153 key_ref_t dest_ref;
David Howells4a38e122008-04-29 01:01:24 -0700154 size_t callout_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 char type[32], *description, *callout_info;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800156 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158 /* pull the type into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800159 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 if (ret < 0)
161 goto error;
David Howells1260f802005-08-04 11:50:01 +0100162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 /* pull the description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800164 description = strndup_user(_description, PAGE_SIZE);
165 if (IS_ERR(description)) {
166 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800168 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 /* pull the callout info into kernel space */
171 callout_info = NULL;
David Howells4a38e122008-04-29 01:01:24 -0700172 callout_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 if (_callout_info) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800174 callout_info = strndup_user(_callout_info, PAGE_SIZE);
175 if (IS_ERR(callout_info)) {
176 ret = PTR_ERR(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 goto error2;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800178 }
David Howells4a38e122008-04-29 01:01:24 -0700179 callout_len = strlen(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 }
181
182 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100183 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100185 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
186 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100187 if (IS_ERR(dest_ref)) {
188 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 goto error3;
190 }
191 }
192
193 /* find the key type */
194 ktype = key_type_lookup(type);
195 if (IS_ERR(ktype)) {
196 ret = PTR_ERR(ktype);
197 goto error4;
198 }
199
200 /* do the search */
David Howells4a38e122008-04-29 01:01:24 -0700201 key = request_key_and_link(ktype, description, callout_info,
202 callout_len, NULL, key_ref_to_ptr(dest_ref),
David Howells7e047ef2006-06-26 00:24:50 -0700203 KEY_ALLOC_IN_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if (IS_ERR(key)) {
205 ret = PTR_ERR(key);
206 goto error5;
207 }
208
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 ret = key->serial;
210
David Howells3e301482005-06-23 22:00:56 -0700211 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700212error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700214error4:
David Howells664cceb2005-09-28 17:03:15 +0100215 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700216error3:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 kfree(callout_info);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700218error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700220error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000222}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224/*
David Howells973c9f42011-01-20 16:38:33 +0000225 * Get the ID of the specified process keyring.
226 *
227 * The requested keyring must have search permission to be found.
228 *
229 * If successful, the ID of the requested keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 */
231long keyctl_get_keyring_ID(key_serial_t id, int create)
232{
David Howells664cceb2005-09-28 17:03:15 +0100233 key_ref_t key_ref;
David Howells55931222009-09-02 09:13:45 +0100234 unsigned long lflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 long ret;
236
David Howells55931222009-09-02 09:13:45 +0100237 lflags = create ? KEY_LOOKUP_CREATE : 0;
238 key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100239 if (IS_ERR(key_ref)) {
240 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 goto error;
242 }
243
David Howells664cceb2005-09-28 17:03:15 +0100244 ret = key_ref_to_ptr(key_ref)->serial;
245 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700246error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 return ret;
David Howells973c9f42011-01-20 16:38:33 +0000248}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250/*
David Howells973c9f42011-01-20 16:38:33 +0000251 * Join a (named) session keyring.
252 *
253 * Create and join an anonymous session keyring or join a named session
254 * keyring, creating it if necessary. A named session keyring must have Search
255 * permission for it to be joined. Session keyrings without this permit will
256 * be skipped over.
257 *
258 * If successful, the ID of the joined session keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 */
260long keyctl_join_session_keyring(const char __user *_name)
261{
262 char *name;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800263 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265 /* fetch the name from userspace */
266 name = NULL;
267 if (_name) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800268 name = strndup_user(_name, PAGE_SIZE);
269 if (IS_ERR(name)) {
270 ret = PTR_ERR(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800272 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 }
274
275 /* join the session */
276 ret = join_session_keyring(name);
Vegard Nossum0d54ee12009-01-17 17:45:45 +0100277 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700279error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000281}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283/*
David Howells973c9f42011-01-20 16:38:33 +0000284 * Update a key's data payload from the given data.
285 *
286 * The key must grant the caller Write permission and the key type must support
287 * updating for this to work. A negative key can be positively instantiated
288 * with this call.
289 *
290 * If successful, 0 will be returned. If the key type does not support
291 * updating, then -EOPNOTSUPP will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 */
293long keyctl_update_key(key_serial_t id,
294 const void __user *_payload,
295 size_t plen)
296{
David Howells664cceb2005-09-28 17:03:15 +0100297 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 void *payload;
299 long ret;
300
301 ret = -EINVAL;
302 if (plen > PAGE_SIZE)
303 goto error;
304
305 /* pull the payload in if one was supplied */
306 payload = NULL;
307 if (_payload) {
308 ret = -ENOMEM;
309 payload = kmalloc(plen, GFP_KERNEL);
310 if (!payload)
311 goto error;
312
313 ret = -EFAULT;
314 if (copy_from_user(payload, _payload, plen) != 0)
315 goto error2;
316 }
317
318 /* find the target key (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100319 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100320 if (IS_ERR(key_ref)) {
321 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 goto error2;
323 }
324
325 /* update the key */
David Howells664cceb2005-09-28 17:03:15 +0100326 ret = key_update(key_ref, payload, plen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
David Howells664cceb2005-09-28 17:03:15 +0100328 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700329error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 kfree(payload);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700331error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000333}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335/*
David Howells973c9f42011-01-20 16:38:33 +0000336 * Revoke a key.
337 *
338 * The key must be grant the caller Write or Setattr permission for this to
339 * work. The key type should give up its quota claim when revoked. The key
340 * and any links to the key will be automatically garbage collected after a
341 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
342 *
343 * If successful, 0 is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 */
345long keyctl_revoke_key(key_serial_t id)
346{
David Howells664cceb2005-09-28 17:03:15 +0100347 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 long ret;
349
David Howells55931222009-09-02 09:13:45 +0100350 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100351 if (IS_ERR(key_ref)) {
352 ret = PTR_ERR(key_ref);
David Howells0c2c9a32009-09-02 09:13:50 +0100353 if (ret != -EACCES)
354 goto error;
355 key_ref = lookup_user_key(id, 0, KEY_SETATTR);
356 if (IS_ERR(key_ref)) {
357 ret = PTR_ERR(key_ref);
358 goto error;
359 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 }
361
David Howells664cceb2005-09-28 17:03:15 +0100362 key_revoke(key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 ret = 0;
364
David Howells664cceb2005-09-28 17:03:15 +0100365 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700366error:
David Howells1260f802005-08-04 11:50:01 +0100367 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000368}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370/*
David Howells973c9f42011-01-20 16:38:33 +0000371 * Clear the specified keyring, creating an empty process keyring if one of the
372 * special keyring IDs is used.
373 *
374 * The keyring must grant the caller Write permission for this to work. If
375 * successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 */
377long keyctl_keyring_clear(key_serial_t ringid)
378{
David Howells664cceb2005-09-28 17:03:15 +0100379 key_ref_t keyring_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 long ret;
381
David Howells55931222009-09-02 09:13:45 +0100382 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100383 if (IS_ERR(keyring_ref)) {
384 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 goto error;
386 }
387
David Howells664cceb2005-09-28 17:03:15 +0100388 ret = keyring_clear(key_ref_to_ptr(keyring_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
David Howells664cceb2005-09-28 17:03:15 +0100390 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700391error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000393}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395/*
David Howells973c9f42011-01-20 16:38:33 +0000396 * Create a link from a keyring to a key if there's no matching key in the
397 * keyring, otherwise replace the link to the matching key with a link to the
398 * new key.
399 *
400 * The key must grant the caller Link permission and the the keyring must grant
401 * the caller Write permission. Furthermore, if an additional link is created,
402 * the keyring's quota will be extended.
403 *
404 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 */
406long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
407{
David Howells664cceb2005-09-28 17:03:15 +0100408 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 long ret;
410
David Howells55931222009-09-02 09:13:45 +0100411 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100412 if (IS_ERR(keyring_ref)) {
413 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 goto error;
415 }
416
David Howells55931222009-09-02 09:13:45 +0100417 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
David Howells664cceb2005-09-28 17:03:15 +0100418 if (IS_ERR(key_ref)) {
419 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 goto error2;
421 }
422
David Howells664cceb2005-09-28 17:03:15 +0100423 ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
David Howells664cceb2005-09-28 17:03:15 +0100425 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700426error2:
David Howells664cceb2005-09-28 17:03:15 +0100427 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700428error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000430}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432/*
David Howells973c9f42011-01-20 16:38:33 +0000433 * Unlink a key from a keyring.
434 *
435 * The keyring must grant the caller Write permission for this to work; the key
436 * itself need not grant the caller anything. If the last link to a key is
437 * removed then that key will be scheduled for destruction.
438 *
439 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 */
441long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
442{
David Howells664cceb2005-09-28 17:03:15 +0100443 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 long ret;
445
David Howells55931222009-09-02 09:13:45 +0100446 keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100447 if (IS_ERR(keyring_ref)) {
448 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 goto error;
450 }
451
David Howells55931222009-09-02 09:13:45 +0100452 key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
David Howells664cceb2005-09-28 17:03:15 +0100453 if (IS_ERR(key_ref)) {
454 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 goto error2;
456 }
457
David Howells664cceb2005-09-28 17:03:15 +0100458 ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
David Howells664cceb2005-09-28 17:03:15 +0100460 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700461error2:
David Howells664cceb2005-09-28 17:03:15 +0100462 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700463error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000465}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467/*
David Howells973c9f42011-01-20 16:38:33 +0000468 * Return a description of a key to userspace.
469 *
470 * The key must grant the caller View permission for this to work.
471 *
472 * If there's a buffer, we place up to buflen bytes of data into it formatted
473 * in the following way:
474 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 * type;uid;gid;perm;description<NUL>
David Howells973c9f42011-01-20 16:38:33 +0000476 *
477 * If successful, we return the amount of description available, irrespective
478 * of how much we may have copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 */
480long keyctl_describe_key(key_serial_t keyid,
481 char __user *buffer,
482 size_t buflen)
483{
David Howells3e301482005-06-23 22:00:56 -0700484 struct key *key, *instkey;
David Howells664cceb2005-09-28 17:03:15 +0100485 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 char *tmpbuf;
487 long ret;
488
David Howells55931222009-09-02 09:13:45 +0100489 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells664cceb2005-09-28 17:03:15 +0100490 if (IS_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700491 /* viewing a key under construction is permitted if we have the
492 * authorisation token handy */
David Howells664cceb2005-09-28 17:03:15 +0100493 if (PTR_ERR(key_ref) == -EACCES) {
David Howells3e301482005-06-23 22:00:56 -0700494 instkey = key_get_instantiation_authkey(keyid);
495 if (!IS_ERR(instkey)) {
496 key_put(instkey);
David Howells8bbf49762008-11-14 10:39:14 +1100497 key_ref = lookup_user_key(keyid,
David Howells55931222009-09-02 09:13:45 +0100498 KEY_LOOKUP_PARTIAL,
499 0);
David Howells664cceb2005-09-28 17:03:15 +0100500 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700501 goto okay;
502 }
503 }
504
David Howells664cceb2005-09-28 17:03:15 +0100505 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 goto error;
507 }
508
David Howells3e301482005-06-23 22:00:56 -0700509okay:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 /* calculate how much description we're going to return */
511 ret = -ENOMEM;
512 tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
513 if (!tmpbuf)
514 goto error2;
515
David Howells664cceb2005-09-28 17:03:15 +0100516 key = key_ref_to_ptr(key_ref);
517
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 ret = snprintf(tmpbuf, PAGE_SIZE - 1,
David Howells664cceb2005-09-28 17:03:15 +0100519 "%s;%d;%d;%08x;%s",
David Howells94fd8402010-06-28 14:05:04 +0100520 key->type->name,
521 key->uid,
522 key->gid,
523 key->perm,
524 key->description ?: "");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525
526 /* include a NUL char at the end of the data */
527 if (ret > PAGE_SIZE - 1)
528 ret = PAGE_SIZE - 1;
529 tmpbuf[ret] = 0;
530 ret++;
531
532 /* consider returning the data */
533 if (buffer && buflen > 0) {
534 if (buflen > ret)
535 buflen = ret;
536
537 if (copy_to_user(buffer, tmpbuf, buflen) != 0)
538 ret = -EFAULT;
539 }
540
541 kfree(tmpbuf);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700542error2:
David Howells664cceb2005-09-28 17:03:15 +0100543 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700544error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000546}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548/*
David Howells973c9f42011-01-20 16:38:33 +0000549 * Search the specified keyring and any keyrings it links to for a matching
550 * key. Only keyrings that grant the caller Search permission will be searched
551 * (this includes the starting keyring). Only keys with Search permission can
552 * be found.
553 *
554 * If successful, the found key will be linked to the destination keyring if
555 * supplied and the key has Link permission, and the found key ID will be
556 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 */
558long keyctl_keyring_search(key_serial_t ringid,
559 const char __user *_type,
560 const char __user *_description,
561 key_serial_t destringid)
562{
563 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100564 key_ref_t keyring_ref, key_ref, dest_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 char type[32], *description;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800566 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 /* pull the type and description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800569 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 if (ret < 0)
571 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800573 description = strndup_user(_description, PAGE_SIZE);
574 if (IS_ERR(description)) {
575 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800577 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579 /* get the keyring at which to begin the search */
David Howells55931222009-09-02 09:13:45 +0100580 keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100581 if (IS_ERR(keyring_ref)) {
582 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 goto error2;
584 }
585
586 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100587 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100589 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
590 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100591 if (IS_ERR(dest_ref)) {
592 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 goto error3;
594 }
595 }
596
597 /* find the key type */
598 ktype = key_type_lookup(type);
599 if (IS_ERR(ktype)) {
600 ret = PTR_ERR(ktype);
601 goto error4;
602 }
603
604 /* do the search */
David Howells664cceb2005-09-28 17:03:15 +0100605 key_ref = keyring_search(keyring_ref, ktype, description);
606 if (IS_ERR(key_ref)) {
607 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
609 /* treat lack or presence of a negative key the same */
610 if (ret == -EAGAIN)
611 ret = -ENOKEY;
612 goto error5;
613 }
614
615 /* link the resulting key to the destination keyring if we can */
David Howells664cceb2005-09-28 17:03:15 +0100616 if (dest_ref) {
David Howells29db9192005-10-30 15:02:44 -0800617 ret = key_permission(key_ref, KEY_LINK);
618 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 goto error6;
620
David Howells664cceb2005-09-28 17:03:15 +0100621 ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 if (ret < 0)
623 goto error6;
624 }
625
David Howells664cceb2005-09-28 17:03:15 +0100626 ret = key_ref_to_ptr(key_ref)->serial;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700628error6:
David Howells664cceb2005-09-28 17:03:15 +0100629 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700630error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700632error4:
David Howells664cceb2005-09-28 17:03:15 +0100633 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700634error3:
David Howells664cceb2005-09-28 17:03:15 +0100635 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700636error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700638error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000640}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642/*
David Howells973c9f42011-01-20 16:38:33 +0000643 * Read a key's payload.
644 *
645 * The key must either grant the caller Read permission, or it must grant the
646 * caller Search permission when searched for from the process keyrings.
647 *
648 * If successful, we place up to buflen bytes of data into the buffer, if one
649 * is provided, and return the amount of data that is available in the key,
650 * irrespective of how much we copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 */
652long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
653{
David Howells664cceb2005-09-28 17:03:15 +0100654 struct key *key;
655 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 long ret;
657
658 /* find the key first */
David Howells55931222009-09-02 09:13:45 +0100659 key_ref = lookup_user_key(keyid, 0, 0);
David Howells664cceb2005-09-28 17:03:15 +0100660 if (IS_ERR(key_ref)) {
661 ret = -ENOKEY;
662 goto error;
663 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
David Howells664cceb2005-09-28 17:03:15 +0100665 key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666
David Howells664cceb2005-09-28 17:03:15 +0100667 /* see if we can read it directly */
David Howells29db9192005-10-30 15:02:44 -0800668 ret = key_permission(key_ref, KEY_READ);
669 if (ret == 0)
David Howells664cceb2005-09-28 17:03:15 +0100670 goto can_read_key;
David Howells29db9192005-10-30 15:02:44 -0800671 if (ret != -EACCES)
672 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100673
674 /* we can't; see if it's searchable from this process's keyrings
675 * - we automatically take account of the fact that it may be
676 * dangling off an instantiation key
677 */
678 if (!is_key_possessed(key_ref)) {
679 ret = -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 goto error2;
681 }
682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 /* the key is probably readable - now try to read it */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700684can_read_key:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 ret = key_validate(key);
686 if (ret == 0) {
687 ret = -EOPNOTSUPP;
688 if (key->type->read) {
689 /* read the data with the semaphore held (since we
690 * might sleep) */
691 down_read(&key->sem);
692 ret = key->type->read(key, buffer, buflen);
693 up_read(&key->sem);
694 }
695 }
696
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700697error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700699error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000701}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703/*
David Howells973c9f42011-01-20 16:38:33 +0000704 * Change the ownership of a key
705 *
706 * The key must grant the caller Setattr permission for this to work, though
707 * the key need not be fully instantiated yet. For the UID to be changed, or
708 * for the GID to be changed to a group the caller is not a member of, the
709 * caller must have sysadmin capability. If either uid or gid is -1 then that
710 * attribute is not changed.
711 *
712 * If the UID is to be changed, the new user must have sufficient quota to
713 * accept the key. The quota deduction will be removed from the old user to
714 * the new user should the attribute be changed.
715 *
716 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 */
718long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
719{
Fredrik Tolf58016492006-06-26 00:24:51 -0700720 struct key_user *newowner, *zapowner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100722 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 long ret;
724
725 ret = 0;
726 if (uid == (uid_t) -1 && gid == (gid_t) -1)
727 goto error;
728
David Howells55931222009-09-02 09:13:45 +0100729 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
730 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100731 if (IS_ERR(key_ref)) {
732 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 goto error;
734 }
735
David Howells664cceb2005-09-28 17:03:15 +0100736 key = key_ref_to_ptr(key_ref);
737
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 /* make the changes with the locks held to prevent chown/chown races */
739 ret = -EACCES;
740 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
742 if (!capable(CAP_SYS_ADMIN)) {
743 /* only the sysadmin can chown a key to some other UID */
744 if (uid != (uid_t) -1 && key->uid != uid)
Fredrik Tolf58016492006-06-26 00:24:51 -0700745 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746
747 /* only the sysadmin can set the key's GID to a group other
748 * than one of those that the current process subscribes to */
749 if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700750 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 }
752
Fredrik Tolf58016492006-06-26 00:24:51 -0700753 /* change the UID */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 if (uid != (uid_t) -1 && uid != key->uid) {
Fredrik Tolf58016492006-06-26 00:24:51 -0700755 ret = -ENOMEM;
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -0600756 newowner = key_user_lookup(uid, current_user_ns());
Fredrik Tolf58016492006-06-26 00:24:51 -0700757 if (!newowner)
758 goto error_put;
759
760 /* transfer the quota burden to the new user */
761 if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
David Howells0b77f5b2008-04-29 01:01:32 -0700762 unsigned maxkeys = (uid == 0) ?
763 key_quota_root_maxkeys : key_quota_maxkeys;
764 unsigned maxbytes = (uid == 0) ?
765 key_quota_root_maxbytes : key_quota_maxbytes;
766
Fredrik Tolf58016492006-06-26 00:24:51 -0700767 spin_lock(&newowner->lock);
David Howells0b77f5b2008-04-29 01:01:32 -0700768 if (newowner->qnkeys + 1 >= maxkeys ||
769 newowner->qnbytes + key->quotalen >= maxbytes ||
770 newowner->qnbytes + key->quotalen <
771 newowner->qnbytes)
Fredrik Tolf58016492006-06-26 00:24:51 -0700772 goto quota_overrun;
773
774 newowner->qnkeys++;
775 newowner->qnbytes += key->quotalen;
776 spin_unlock(&newowner->lock);
777
778 spin_lock(&key->user->lock);
779 key->user->qnkeys--;
780 key->user->qnbytes -= key->quotalen;
781 spin_unlock(&key->user->lock);
782 }
783
784 atomic_dec(&key->user->nkeys);
785 atomic_inc(&newowner->nkeys);
786
787 if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
788 atomic_dec(&key->user->nikeys);
789 atomic_inc(&newowner->nikeys);
790 }
791
792 zapowner = key->user;
793 key->user = newowner;
794 key->uid = uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 }
796
797 /* change the GID */
798 if (gid != (gid_t) -1)
799 key->gid = gid;
800
801 ret = 0;
802
Fredrik Tolf58016492006-06-26 00:24:51 -0700803error_put:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 up_write(&key->sem);
805 key_put(key);
Fredrik Tolf58016492006-06-26 00:24:51 -0700806 if (zapowner)
807 key_user_put(zapowner);
808error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 return ret;
810
Fredrik Tolf58016492006-06-26 00:24:51 -0700811quota_overrun:
812 spin_unlock(&newowner->lock);
813 zapowner = newowner;
814 ret = -EDQUOT;
815 goto error_put;
David Howellsa8b17ed2011-01-20 16:38:27 +0000816}
Fredrik Tolf58016492006-06-26 00:24:51 -0700817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818/*
David Howells973c9f42011-01-20 16:38:33 +0000819 * Change the permission mask on a key.
820 *
821 * The key must grant the caller Setattr permission for this to work, though
822 * the key need not be fully instantiated yet. If the caller does not have
823 * sysadmin capability, it may only change the permission on keys that it owns.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 */
825long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
826{
827 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100828 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 long ret;
830
831 ret = -EINVAL;
David Howells664cceb2005-09-28 17:03:15 +0100832 if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 goto error;
834
David Howells55931222009-09-02 09:13:45 +0100835 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
836 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100837 if (IS_ERR(key_ref)) {
838 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 goto error;
840 }
841
David Howells664cceb2005-09-28 17:03:15 +0100842 key = key_ref_to_ptr(key_ref);
843
David Howells76d8aea2005-06-23 22:00:49 -0700844 /* make the changes with the locks held to prevent chown/chmod races */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 ret = -EACCES;
846 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847
David Howells76d8aea2005-06-23 22:00:49 -0700848 /* if we're not the sysadmin, we can only change a key that we own */
David Howells47d804b2008-11-14 10:39:11 +1100849 if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) {
David Howells76d8aea2005-06-23 22:00:49 -0700850 key->perm = perm;
851 ret = 0;
852 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 up_write(&key->sem);
855 key_put(key);
David Howells76d8aea2005-06-23 22:00:49 -0700856error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000858}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
David Howells8bbf49762008-11-14 10:39:14 +1100860/*
David Howells973c9f42011-01-20 16:38:33 +0000861 * Get the destination keyring for instantiation and check that the caller has
862 * Write permission on it.
David Howells8bbf49762008-11-14 10:39:14 +1100863 */
864static long get_instantiation_keyring(key_serial_t ringid,
865 struct request_key_auth *rka,
866 struct key **_dest_keyring)
867{
868 key_ref_t dkref;
869
David Howellseca1bf52008-12-29 00:41:51 +0000870 *_dest_keyring = NULL;
871
David Howells8bbf49762008-11-14 10:39:14 +1100872 /* just return a NULL pointer if we weren't asked to make a link */
David Howellseca1bf52008-12-29 00:41:51 +0000873 if (ringid == 0)
David Howells8bbf49762008-11-14 10:39:14 +1100874 return 0;
David Howells8bbf49762008-11-14 10:39:14 +1100875
876 /* if a specific keyring is nominated by ID, then use that */
877 if (ringid > 0) {
David Howells55931222009-09-02 09:13:45 +0100878 dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells8bbf49762008-11-14 10:39:14 +1100879 if (IS_ERR(dkref))
880 return PTR_ERR(dkref);
881 *_dest_keyring = key_ref_to_ptr(dkref);
882 return 0;
883 }
884
885 if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
886 return -EINVAL;
887
888 /* otherwise specify the destination keyring recorded in the
889 * authorisation key (any KEY_SPEC_*_KEYRING) */
890 if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
David Howells21279cf2009-10-15 10:14:35 +0100891 *_dest_keyring = key_get(rka->dest_keyring);
David Howells8bbf49762008-11-14 10:39:14 +1100892 return 0;
893 }
894
895 return -ENOKEY;
896}
897
David Howellsd84f4f92008-11-14 10:39:23 +1100898/*
David Howells973c9f42011-01-20 16:38:33 +0000899 * Change the request_key authorisation key on the current process.
David Howellsd84f4f92008-11-14 10:39:23 +1100900 */
901static int keyctl_change_reqkey_auth(struct key *key)
902{
903 struct cred *new;
904
905 new = prepare_creds();
906 if (!new)
907 return -ENOMEM;
908
909 key_put(new->request_key_auth);
910 new->request_key_auth = key_get(key);
911
912 return commit_creds(new);
913}
914
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915/*
David Howells973c9f42011-01-20 16:38:33 +0000916 * Instantiate a key with the specified payload and link the key into the
917 * destination keyring if one is given.
918 *
919 * The caller must have the appropriate instantiation permit set for this to
920 * work (see keyctl_assume_authority). No other permissions are required.
921 *
922 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 */
924long keyctl_instantiate_key(key_serial_t id,
925 const void __user *_payload,
926 size_t plen,
927 key_serial_t ringid)
928{
David Howellsd84f4f92008-11-14 10:39:23 +1100929 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -0700930 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +1100931 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 void *payload;
933 long ret;
David Howells38bbca62008-04-29 01:01:19 -0700934 bool vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
David Howellsd84f4f92008-11-14 10:39:23 +1100936 kenter("%d,,%zu,%d", id, plen, ringid);
937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -0700939 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 goto error;
941
David Howellsb5f545c2006-01-08 01:02:47 -0800942 /* the appropriate instantiation authorisation key must have been
943 * assumed before calling this */
944 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +1100945 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -0800946 if (!instkey)
947 goto error;
948
949 rka = instkey->payload.data;
950 if (rka->target_key->serial != id)
951 goto error;
952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 /* pull the payload in if one was supplied */
954 payload = NULL;
955
956 if (_payload) {
957 ret = -ENOMEM;
958 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -0700959 if (!payload) {
960 if (plen <= PAGE_SIZE)
961 goto error;
962 vm = true;
963 payload = vmalloc(plen);
964 if (!payload)
965 goto error;
966 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
968 ret = -EFAULT;
969 if (copy_from_user(payload, _payload, plen) != 0)
970 goto error2;
971 }
972
David Howells3e301482005-06-23 22:00:56 -0700973 /* find the destination keyring amongst those belonging to the
974 * requesting task */
David Howells8bbf49762008-11-14 10:39:14 +1100975 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
976 if (ret < 0)
977 goto error2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979 /* instantiate the key and link it into a keyring */
David Howells3e301482005-06-23 22:00:56 -0700980 ret = key_instantiate_and_link(rka->target_key, payload, plen,
David Howells8bbf49762008-11-14 10:39:14 +1100981 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982
David Howells8bbf49762008-11-14 10:39:14 +1100983 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -0800984
985 /* discard the assumed authority if it's just been disabled by
986 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +1100987 if (ret == 0)
988 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -0800989
990error2:
David Howells38bbca62008-04-29 01:01:19 -0700991 if (!vm)
992 kfree(payload);
993 else
994 vfree(payload);
David Howellsb5f545c2006-01-08 01:02:47 -0800995error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000997}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999/*
David Howells973c9f42011-01-20 16:38:33 +00001000 * Negatively instantiate the key with the given timeout (in seconds) and link
1001 * the key into the destination keyring if one is given.
1002 *
1003 * The caller must have the appropriate instantiation permit set for this to
1004 * work (see keyctl_assume_authority). No other permissions are required.
1005 *
1006 * The key and any links to the key will be automatically garbage collected
1007 * after the timeout expires.
1008 *
1009 * Negative keys are used to rate limit repeated request_key() calls by causing
1010 * them to return -ENOKEY until the negative key expires.
1011 *
1012 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 */
1014long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
1015{
David Howellsd84f4f92008-11-14 10:39:23 +11001016 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001017 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001018 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 long ret;
1020
David Howellsd84f4f92008-11-14 10:39:23 +11001021 kenter("%d,%u,%d", id, timeout, ringid);
1022
David Howellsb5f545c2006-01-08 01:02:47 -08001023 /* the appropriate instantiation authorisation key must have been
1024 * assumed before calling this */
1025 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001026 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001027 if (!instkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029
David Howells3e301482005-06-23 22:00:56 -07001030 rka = instkey->payload.data;
David Howellsb5f545c2006-01-08 01:02:47 -08001031 if (rka->target_key->serial != id)
1032 goto error;
David Howells3e301482005-06-23 22:00:56 -07001033
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 /* find the destination keyring if present (which must also be
1035 * writable) */
David Howells8bbf49762008-11-14 10:39:14 +11001036 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1037 if (ret < 0)
1038 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039
1040 /* instantiate the key and link it into a keyring */
David Howells664cceb2005-09-28 17:03:15 +01001041 ret = key_negate_and_link(rka->target_key, timeout,
David Howells8bbf49762008-11-14 10:39:14 +11001042 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043
David Howells8bbf49762008-11-14 10:39:14 +11001044 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001045
1046 /* discard the assumed authority if it's just been disabled by
1047 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001048 if (ret == 0)
1049 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001050
1051error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001053}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055/*
David Howells973c9f42011-01-20 16:38:33 +00001056 * Read or set the default keyring in which request_key() will cache keys and
1057 * return the old setting.
1058 *
1059 * If a process keyring is specified then this will be created if it doesn't
1060 * yet exist. The old setting will be returned if successful.
David Howells3e301482005-06-23 22:00:56 -07001061 */
1062long keyctl_set_reqkey_keyring(int reqkey_defl)
1063{
David Howellsd84f4f92008-11-14 10:39:23 +11001064 struct cred *new;
1065 int ret, old_setting;
1066
1067 old_setting = current_cred_xxx(jit_keyring);
1068
1069 if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
1070 return old_setting;
1071
1072 new = prepare_creds();
1073 if (!new)
1074 return -ENOMEM;
David Howells3e301482005-06-23 22:00:56 -07001075
1076 switch (reqkey_defl) {
1077 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001078 ret = install_thread_keyring_to_cred(new);
David Howells3e301482005-06-23 22:00:56 -07001079 if (ret < 0)
David Howellsd84f4f92008-11-14 10:39:23 +11001080 goto error;
David Howells3e301482005-06-23 22:00:56 -07001081 goto set;
1082
1083 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001084 ret = install_process_keyring_to_cred(new);
1085 if (ret < 0) {
1086 if (ret != -EEXIST)
1087 goto error;
1088 ret = 0;
1089 }
1090 goto set;
David Howells3e301482005-06-23 22:00:56 -07001091
1092 case KEY_REQKEY_DEFL_DEFAULT:
1093 case KEY_REQKEY_DEFL_SESSION_KEYRING:
1094 case KEY_REQKEY_DEFL_USER_KEYRING:
1095 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001096 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
1097 goto set;
David Howells3e301482005-06-23 22:00:56 -07001098
1099 case KEY_REQKEY_DEFL_NO_CHANGE:
David Howells3e301482005-06-23 22:00:56 -07001100 case KEY_REQKEY_DEFL_GROUP_KEYRING:
1101 default:
David Howellsd84f4f92008-11-14 10:39:23 +11001102 ret = -EINVAL;
1103 goto error;
David Howells3e301482005-06-23 22:00:56 -07001104 }
1105
David Howellsd84f4f92008-11-14 10:39:23 +11001106set:
1107 new->jit_keyring = reqkey_defl;
1108 commit_creds(new);
1109 return old_setting;
1110error:
1111 abort_creds(new);
Dan Carpenter4303ef12010-06-11 17:30:05 +01001112 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001113}
David Howellsd84f4f92008-11-14 10:39:23 +11001114
David Howells3e301482005-06-23 22:00:56 -07001115/*
David Howells973c9f42011-01-20 16:38:33 +00001116 * Set or clear the timeout on a key.
1117 *
1118 * Either the key must grant the caller Setattr permission or else the caller
1119 * must hold an instantiation authorisation token for the key.
1120 *
1121 * The timeout is either 0 to clear the timeout, or a number of seconds from
1122 * the current time. The key and any links to the key will be automatically
1123 * garbage collected after the timeout expires.
1124 *
1125 * If successful, 0 is returned.
David Howells017679c2006-01-08 01:02:43 -08001126 */
1127long keyctl_set_timeout(key_serial_t id, unsigned timeout)
1128{
1129 struct timespec now;
David Howells91562352010-06-11 17:31:05 +01001130 struct key *key, *instkey;
David Howells017679c2006-01-08 01:02:43 -08001131 key_ref_t key_ref;
1132 time_t expiry;
1133 long ret;
1134
David Howells55931222009-09-02 09:13:45 +01001135 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
1136 KEY_SETATTR);
David Howells017679c2006-01-08 01:02:43 -08001137 if (IS_ERR(key_ref)) {
David Howells91562352010-06-11 17:31:05 +01001138 /* setting the timeout on a key under construction is permitted
1139 * if we have the authorisation token handy */
1140 if (PTR_ERR(key_ref) == -EACCES) {
1141 instkey = key_get_instantiation_authkey(id);
1142 if (!IS_ERR(instkey)) {
1143 key_put(instkey);
1144 key_ref = lookup_user_key(id,
1145 KEY_LOOKUP_PARTIAL,
1146 0);
1147 if (!IS_ERR(key_ref))
1148 goto okay;
1149 }
1150 }
1151
David Howells017679c2006-01-08 01:02:43 -08001152 ret = PTR_ERR(key_ref);
1153 goto error;
1154 }
1155
David Howells91562352010-06-11 17:31:05 +01001156okay:
David Howells017679c2006-01-08 01:02:43 -08001157 key = key_ref_to_ptr(key_ref);
1158
1159 /* make the changes with the locks held to prevent races */
1160 down_write(&key->sem);
1161
1162 expiry = 0;
1163 if (timeout > 0) {
1164 now = current_kernel_time();
1165 expiry = now.tv_sec + timeout;
1166 }
1167
1168 key->expiry = expiry;
David Howellsc08ef802009-09-14 17:26:13 +01001169 key_schedule_gc(key->expiry + key_gc_delay);
David Howells017679c2006-01-08 01:02:43 -08001170
1171 up_write(&key->sem);
1172 key_put(key);
1173
1174 ret = 0;
1175error:
1176 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001177}
David Howells017679c2006-01-08 01:02:43 -08001178
David Howells017679c2006-01-08 01:02:43 -08001179/*
David Howells973c9f42011-01-20 16:38:33 +00001180 * Assume (or clear) the authority to instantiate the specified key.
1181 *
1182 * This sets the authoritative token currently in force for key instantiation.
1183 * This must be done for a key to be instantiated. It has the effect of making
1184 * available all the keys from the caller of the request_key() that created a
1185 * key to request_key() calls made by the caller of this function.
1186 *
1187 * The caller must have the instantiation key in their process keyrings with a
1188 * Search permission grant available to the caller.
1189 *
1190 * If the ID given is 0, then the setting will be cleared and 0 returned.
1191 *
1192 * If the ID given has a matching an authorisation key, then that key will be
1193 * set and its ID will be returned. The authorisation key can be read to get
1194 * the callout information passed to request_key().
David Howellsb5f545c2006-01-08 01:02:47 -08001195 */
1196long keyctl_assume_authority(key_serial_t id)
1197{
1198 struct key *authkey;
1199 long ret;
1200
1201 /* special key IDs aren't permitted */
1202 ret = -EINVAL;
1203 if (id < 0)
1204 goto error;
1205
1206 /* we divest ourselves of authority if given an ID of 0 */
1207 if (id == 0) {
David Howellsd84f4f92008-11-14 10:39:23 +11001208 ret = keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001209 goto error;
1210 }
1211
1212 /* attempt to assume the authority temporarily granted to us whilst we
1213 * instantiate the specified key
1214 * - the authorisation key must be in the current task's keyrings
1215 * somewhere
1216 */
1217 authkey = key_get_instantiation_authkey(id);
1218 if (IS_ERR(authkey)) {
1219 ret = PTR_ERR(authkey);
1220 goto error;
1221 }
1222
David Howellsd84f4f92008-11-14 10:39:23 +11001223 ret = keyctl_change_reqkey_auth(authkey);
1224 if (ret < 0)
1225 goto error;
1226 key_put(authkey);
David Howellsb5f545c2006-01-08 01:02:47 -08001227
David Howellsd84f4f92008-11-14 10:39:23 +11001228 ret = authkey->serial;
David Howellsb5f545c2006-01-08 01:02:47 -08001229error:
1230 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001231}
David Howellsb5f545c2006-01-08 01:02:47 -08001232
David Howells70a5bb72008-04-29 01:01:26 -07001233/*
David Howells973c9f42011-01-20 16:38:33 +00001234 * Get a key's the LSM security label.
1235 *
1236 * The key must grant the caller View permission for this to work.
1237 *
1238 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1239 *
1240 * If successful, the amount of information available will be returned,
1241 * irrespective of how much was copied (including the terminal NUL).
David Howells70a5bb72008-04-29 01:01:26 -07001242 */
1243long keyctl_get_security(key_serial_t keyid,
1244 char __user *buffer,
1245 size_t buflen)
1246{
1247 struct key *key, *instkey;
1248 key_ref_t key_ref;
1249 char *context;
1250 long ret;
1251
David Howells55931222009-09-02 09:13:45 +01001252 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells70a5bb72008-04-29 01:01:26 -07001253 if (IS_ERR(key_ref)) {
1254 if (PTR_ERR(key_ref) != -EACCES)
1255 return PTR_ERR(key_ref);
1256
1257 /* viewing a key under construction is also permitted if we
1258 * have the authorisation token handy */
1259 instkey = key_get_instantiation_authkey(keyid);
1260 if (IS_ERR(instkey))
Roel Kluinfa1cc7b2009-12-15 15:05:12 -08001261 return PTR_ERR(instkey);
David Howells70a5bb72008-04-29 01:01:26 -07001262 key_put(instkey);
1263
David Howells55931222009-09-02 09:13:45 +01001264 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
David Howells70a5bb72008-04-29 01:01:26 -07001265 if (IS_ERR(key_ref))
1266 return PTR_ERR(key_ref);
1267 }
1268
1269 key = key_ref_to_ptr(key_ref);
1270 ret = security_key_getsecurity(key, &context);
1271 if (ret == 0) {
1272 /* if no information was returned, give userspace an empty
1273 * string */
1274 ret = 1;
1275 if (buffer && buflen > 0 &&
1276 copy_to_user(buffer, "", 1) != 0)
1277 ret = -EFAULT;
1278 } else if (ret > 0) {
1279 /* return as much data as there's room for */
1280 if (buffer && buflen > 0) {
1281 if (buflen > ret)
1282 buflen = ret;
1283
1284 if (copy_to_user(buffer, context, buflen) != 0)
1285 ret = -EFAULT;
1286 }
1287
1288 kfree(context);
1289 }
1290
1291 key_ref_put(key_ref);
1292 return ret;
1293}
1294
David Howellsee18d642009-09-02 09:14:21 +01001295/*
David Howells973c9f42011-01-20 16:38:33 +00001296 * Attempt to install the calling process's session keyring on the process's
1297 * parent process.
1298 *
1299 * The keyring must exist and must grant the caller LINK permission, and the
1300 * parent process must be single-threaded and must have the same effective
1301 * ownership as this process and mustn't be SUID/SGID.
1302 *
1303 * The keyring will be emplaced on the parent when it next resumes userspace.
1304 *
1305 * If successful, 0 will be returned.
David Howellsee18d642009-09-02 09:14:21 +01001306 */
1307long keyctl_session_to_parent(void)
1308{
Geert Uytterhoevena00ae4d2009-12-13 20:21:34 +01001309#ifdef TIF_NOTIFY_RESUME
David Howellsee18d642009-09-02 09:14:21 +01001310 struct task_struct *me, *parent;
1311 const struct cred *mycred, *pcred;
1312 struct cred *cred, *oldcred;
1313 key_ref_t keyring_r;
1314 int ret;
1315
1316 keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
1317 if (IS_ERR(keyring_r))
1318 return PTR_ERR(keyring_r);
1319
1320 /* our parent is going to need a new cred struct, a new tgcred struct
1321 * and new security data, so we allocate them here to prevent ENOMEM in
1322 * our parent */
1323 ret = -ENOMEM;
1324 cred = cred_alloc_blank();
1325 if (!cred)
1326 goto error_keyring;
1327
1328 cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
1329 keyring_r = NULL;
1330
1331 me = current;
David Howells9d1ac652010-09-10 09:59:46 +01001332 rcu_read_lock();
David Howellsee18d642009-09-02 09:14:21 +01001333 write_lock_irq(&tasklist_lock);
1334
1335 parent = me->real_parent;
1336 ret = -EPERM;
1337
1338 /* the parent mustn't be init and mustn't be a kernel thread */
1339 if (parent->pid <= 1 || !parent->mm)
1340 goto not_permitted;
1341
1342 /* the parent must be single threaded */
Oleg Nesterovdd98acf2010-05-26 14:43:23 -07001343 if (!thread_group_empty(parent))
David Howellsee18d642009-09-02 09:14:21 +01001344 goto not_permitted;
1345
1346 /* the parent and the child must have different session keyrings or
1347 * there's no point */
1348 mycred = current_cred();
1349 pcred = __task_cred(parent);
1350 if (mycred == pcred ||
1351 mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
1352 goto already_same;
1353
1354 /* the parent must have the same effective ownership and mustn't be
1355 * SUID/SGID */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -07001356 if (pcred->uid != mycred->euid ||
David Howellsee18d642009-09-02 09:14:21 +01001357 pcred->euid != mycred->euid ||
1358 pcred->suid != mycred->euid ||
Justin P. Mattockc5b60b52010-04-21 00:02:11 -07001359 pcred->gid != mycred->egid ||
David Howellsee18d642009-09-02 09:14:21 +01001360 pcred->egid != mycred->egid ||
1361 pcred->sgid != mycred->egid)
1362 goto not_permitted;
1363
1364 /* the keyrings must have the same UID */
David Howells3d964062010-09-10 09:59:51 +01001365 if ((pcred->tgcred->session_keyring &&
1366 pcred->tgcred->session_keyring->uid != mycred->euid) ||
David Howellsee18d642009-09-02 09:14:21 +01001367 mycred->tgcred->session_keyring->uid != mycred->euid)
1368 goto not_permitted;
1369
David Howellsee18d642009-09-02 09:14:21 +01001370 /* if there's an already pending keyring replacement, then we replace
1371 * that */
1372 oldcred = parent->replacement_session_keyring;
1373
1374 /* the replacement session keyring is applied just prior to userspace
1375 * restarting */
1376 parent->replacement_session_keyring = cred;
1377 cred = NULL;
1378 set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
1379
1380 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001381 rcu_read_unlock();
David Howellsee18d642009-09-02 09:14:21 +01001382 if (oldcred)
1383 put_cred(oldcred);
1384 return 0;
1385
1386already_same:
1387 ret = 0;
1388not_permitted:
Marc Dionne5c843422009-09-14 12:46:23 +01001389 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001390 rcu_read_unlock();
David Howellsee18d642009-09-02 09:14:21 +01001391 put_cred(cred);
1392 return ret;
1393
1394error_keyring:
1395 key_ref_put(keyring_r);
1396 return ret;
Geert Uytterhoevena00ae4d2009-12-13 20:21:34 +01001397
1398#else /* !TIF_NOTIFY_RESUME */
1399 /*
1400 * To be removed when TIF_NOTIFY_RESUME has been implemented on
1401 * m68k/xtensa
1402 */
1403#warning TIF_NOTIFY_RESUME not implemented
1404 return -EOPNOTSUPP;
1405#endif /* !TIF_NOTIFY_RESUME */
David Howellsee18d642009-09-02 09:14:21 +01001406}
1407
David Howellsb5f545c2006-01-08 01:02:47 -08001408/*
David Howells973c9f42011-01-20 16:38:33 +00001409 * The key control system call
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001411SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
1412 unsigned long, arg4, unsigned long, arg5)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413{
1414 switch (option) {
1415 case KEYCTL_GET_KEYRING_ID:
1416 return keyctl_get_keyring_ID((key_serial_t) arg2,
1417 (int) arg3);
1418
1419 case KEYCTL_JOIN_SESSION_KEYRING:
1420 return keyctl_join_session_keyring((const char __user *) arg2);
1421
1422 case KEYCTL_UPDATE:
1423 return keyctl_update_key((key_serial_t) arg2,
1424 (const void __user *) arg3,
1425 (size_t) arg4);
1426
1427 case KEYCTL_REVOKE:
1428 return keyctl_revoke_key((key_serial_t) arg2);
1429
1430 case KEYCTL_DESCRIBE:
1431 return keyctl_describe_key((key_serial_t) arg2,
1432 (char __user *) arg3,
1433 (unsigned) arg4);
1434
1435 case KEYCTL_CLEAR:
1436 return keyctl_keyring_clear((key_serial_t) arg2);
1437
1438 case KEYCTL_LINK:
1439 return keyctl_keyring_link((key_serial_t) arg2,
1440 (key_serial_t) arg3);
1441
1442 case KEYCTL_UNLINK:
1443 return keyctl_keyring_unlink((key_serial_t) arg2,
1444 (key_serial_t) arg3);
1445
1446 case KEYCTL_SEARCH:
1447 return keyctl_keyring_search((key_serial_t) arg2,
1448 (const char __user *) arg3,
1449 (const char __user *) arg4,
1450 (key_serial_t) arg5);
1451
1452 case KEYCTL_READ:
1453 return keyctl_read_key((key_serial_t) arg2,
1454 (char __user *) arg3,
1455 (size_t) arg4);
1456
1457 case KEYCTL_CHOWN:
1458 return keyctl_chown_key((key_serial_t) arg2,
1459 (uid_t) arg3,
1460 (gid_t) arg4);
1461
1462 case KEYCTL_SETPERM:
1463 return keyctl_setperm_key((key_serial_t) arg2,
1464 (key_perm_t) arg3);
1465
1466 case KEYCTL_INSTANTIATE:
1467 return keyctl_instantiate_key((key_serial_t) arg2,
1468 (const void __user *) arg3,
1469 (size_t) arg4,
1470 (key_serial_t) arg5);
1471
1472 case KEYCTL_NEGATE:
1473 return keyctl_negate_key((key_serial_t) arg2,
1474 (unsigned) arg3,
1475 (key_serial_t) arg4);
1476
David Howells3e301482005-06-23 22:00:56 -07001477 case KEYCTL_SET_REQKEY_KEYRING:
1478 return keyctl_set_reqkey_keyring(arg2);
1479
David Howells017679c2006-01-08 01:02:43 -08001480 case KEYCTL_SET_TIMEOUT:
1481 return keyctl_set_timeout((key_serial_t) arg2,
1482 (unsigned) arg3);
1483
David Howellsb5f545c2006-01-08 01:02:47 -08001484 case KEYCTL_ASSUME_AUTHORITY:
1485 return keyctl_assume_authority((key_serial_t) arg2);
1486
David Howells70a5bb72008-04-29 01:01:26 -07001487 case KEYCTL_GET_SECURITY:
1488 return keyctl_get_security((key_serial_t) arg2,
James Morris90bd49a2008-12-29 14:35:35 +11001489 (char __user *) arg3,
David Howells70a5bb72008-04-29 01:01:26 -07001490 (size_t) arg4);
1491
David Howellsee18d642009-09-02 09:14:21 +01001492 case KEYCTL_SESSION_TO_PARENT:
1493 return keyctl_session_to_parent();
1494
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 default:
1496 return -EOPNOTSUPP;
1497 }
David Howellsa8b17ed2011-01-20 16:38:27 +00001498}