David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1 | /* Manage a process's keyrings |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 3 | * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/init.h> |
| 13 | #include <linux/sched.h> |
Ingo Molnar | 8703e8a | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 14 | #include <linux/sched/user.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/keyctl.h> |
| 16 | #include <linux/fs.h> |
| 17 | #include <linux/err.h> |
Ingo Molnar | bb003079 | 2006-03-22 00:09:14 -0800 | [diff] [blame] | 18 | #include <linux/mutex.h> |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 19 | #include <linux/security.h> |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 20 | #include <linux/user_namespace.h> |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 21 | #include <linux/uaccess.h> |
David Howells | 822ad64 | 2019-02-14 16:20:25 +0000 | [diff] [blame] | 22 | #include <keys/request_key_auth-type.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include "internal.h" |
| 24 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 25 | /* Session keyring create vs join semaphore */ |
Ingo Molnar | bb003079 | 2006-03-22 00:09:14 -0800 | [diff] [blame] | 26 | static DEFINE_MUTEX(key_session_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 28 | /* User keyring creation semaphore */ |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 29 | static DEFINE_MUTEX(key_user_keyring_mutex); |
| 30 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 31 | /* The root user's tracking struct */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | struct key_user root_key_user = { |
Elena Reshetova | ddb99e1 | 2017-03-31 15:20:49 +0300 | [diff] [blame] | 33 | .usage = REFCOUNT_INIT(3), |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 34 | .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock), |
Peter Zijlstra | 6cfd76a | 2006-12-06 20:37:22 -0800 | [diff] [blame] | 35 | .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | .nkeys = ATOMIC_INIT(2), |
| 37 | .nikeys = ATOMIC_INIT(2), |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 38 | .uid = GLOBAL_ROOT_UID, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | }; |
| 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 42 | * Install the user and user session keyrings for the current process's UID. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | */ |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 44 | int install_user_keyrings(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 46 | struct user_struct *user; |
| 47 | const struct cred *cred; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | struct key *uid_keyring, *session_keyring; |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 49 | key_perm_t user_keyring_perm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | char buf[20]; |
| 51 | int ret; |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 52 | uid_t uid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 54 | user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 55 | cred = current_cred(); |
| 56 | user = cred->user; |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 57 | uid = from_kuid(cred->user_ns, user->uid); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 58 | |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 59 | kenter("%p{%u}", user, uid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 61 | if (READ_ONCE(user->uid_keyring) && READ_ONCE(user->session_keyring)) { |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 62 | kleave(" = 0 [exist]"); |
| 63 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | } |
| 65 | |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 66 | mutex_lock(&key_user_keyring_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | ret = 0; |
| 68 | |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 69 | if (!user->uid_keyring) { |
| 70 | /* get the UID-specific keyring |
| 71 | * - there may be one in existence already as it may have been |
| 72 | * pinned by a session, but the user_struct pointing to it |
| 73 | * may have been destroyed by setuid */ |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 74 | sprintf(buf, "_uid.%u", uid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 76 | uid_keyring = find_keyring_by_name(buf, true); |
| 77 | if (IS_ERR(uid_keyring)) { |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 78 | uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID, |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 79 | cred, user_keyring_perm, |
Eric Biggers | 237bbd2 | 2017-09-18 11:37:03 -0700 | [diff] [blame] | 80 | KEY_ALLOC_UID_KEYRING | |
| 81 | KEY_ALLOC_IN_QUOTA, |
David Howells | 5ac7eac | 2016-04-06 16:14:24 +0100 | [diff] [blame] | 82 | NULL, NULL); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 83 | if (IS_ERR(uid_keyring)) { |
| 84 | ret = PTR_ERR(uid_keyring); |
| 85 | goto error; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | /* get a default session keyring (which might also exist |
| 90 | * already) */ |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 91 | sprintf(buf, "_uid_ses.%u", uid); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 92 | |
| 93 | session_keyring = find_keyring_by_name(buf, true); |
| 94 | if (IS_ERR(session_keyring)) { |
| 95 | session_keyring = |
Eric W. Biederman | 9a56c2d | 2012-02-08 07:53:04 -0800 | [diff] [blame] | 96 | keyring_alloc(buf, user->uid, INVALID_GID, |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 97 | cred, user_keyring_perm, |
Eric Biggers | 237bbd2 | 2017-09-18 11:37:03 -0700 | [diff] [blame] | 98 | KEY_ALLOC_UID_KEYRING | |
| 99 | KEY_ALLOC_IN_QUOTA, |
David Howells | 5ac7eac | 2016-04-06 16:14:24 +0100 | [diff] [blame] | 100 | NULL, NULL); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 101 | if (IS_ERR(session_keyring)) { |
| 102 | ret = PTR_ERR(session_keyring); |
| 103 | goto error_release; |
| 104 | } |
| 105 | |
| 106 | /* we install a link from the user session keyring to |
| 107 | * the user keyring */ |
| 108 | ret = key_link(session_keyring, uid_keyring); |
| 109 | if (ret < 0) |
| 110 | goto error_release_both; |
| 111 | } |
| 112 | |
| 113 | /* install the keyrings */ |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 114 | /* paired with READ_ONCE() */ |
| 115 | smp_store_release(&user->uid_keyring, uid_keyring); |
| 116 | /* paired with READ_ONCE() */ |
| 117 | smp_store_release(&user->session_keyring, session_keyring); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | mutex_unlock(&key_user_keyring_mutex); |
| 121 | kleave(" = 0"); |
| 122 | return 0; |
| 123 | |
| 124 | error_release_both: |
| 125 | key_put(session_keyring); |
| 126 | error_release: |
| 127 | key_put(uid_keyring); |
| 128 | error: |
| 129 | mutex_unlock(&key_user_keyring_mutex); |
| 130 | kleave(" = %d", ret); |
| 131 | return ret; |
| 132 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | /* |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 135 | * Install a thread keyring to the given credentials struct if it didn't have |
| 136 | * one already. This is allowed to overrun the quota. |
| 137 | * |
| 138 | * Return: 0 if a thread keyring is now present; -errno on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 140 | int install_thread_keyring_to_cred(struct cred *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 142 | struct key *keyring; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 144 | if (new->thread_keyring) |
| 145 | return 0; |
| 146 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 147 | keyring = keyring_alloc("_tid", new->uid, new->gid, new, |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 148 | KEY_POS_ALL | KEY_USR_VIEW, |
David Howells | 5ac7eac | 2016-04-06 16:14:24 +0100 | [diff] [blame] | 149 | KEY_ALLOC_QUOTA_OVERRUN, |
| 150 | NULL, NULL); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 151 | if (IS_ERR(keyring)) |
| 152 | return PTR_ERR(keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 154 | new->thread_keyring = keyring; |
| 155 | return 0; |
| 156 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | /* |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 159 | * Install a thread keyring to the current task if it didn't have one already. |
| 160 | * |
| 161 | * Return: 0 if a thread keyring is now present; -errno on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 163 | static int install_thread_keyring(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 165 | struct cred *new; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | int ret; |
| 167 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 168 | new = prepare_creds(); |
| 169 | if (!new) |
| 170 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 172 | ret = install_thread_keyring_to_cred(new); |
| 173 | if (ret < 0) { |
| 174 | abort_creds(new); |
| 175 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | } |
| 177 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 178 | return commit_creds(new); |
| 179 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 181 | /* |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 182 | * Install a process keyring to the given credentials struct if it didn't have |
| 183 | * one already. This is allowed to overrun the quota. |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 184 | * |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 185 | * Return: 0 if a process keyring is now present; -errno on failure. |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 186 | */ |
| 187 | int install_process_keyring_to_cred(struct cred *new) |
| 188 | { |
| 189 | struct key *keyring; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 191 | if (new->process_keyring) |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 192 | return 0; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 193 | |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 194 | keyring = keyring_alloc("_pid", new->uid, new->gid, new, |
| 195 | KEY_POS_ALL | KEY_USR_VIEW, |
David Howells | 5ac7eac | 2016-04-06 16:14:24 +0100 | [diff] [blame] | 196 | KEY_ALLOC_QUOTA_OVERRUN, |
| 197 | NULL, NULL); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 198 | if (IS_ERR(keyring)) |
| 199 | return PTR_ERR(keyring); |
| 200 | |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 201 | new->process_keyring = keyring; |
| 202 | return 0; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 203 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | /* |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 206 | * Install a process keyring to the current task if it didn't have one already. |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 207 | * |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 208 | * Return: 0 if a process keyring is now present; -errno on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 210 | static int install_process_keyring(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 212 | struct cred *new; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | int ret; |
| 214 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 215 | new = prepare_creds(); |
| 216 | if (!new) |
| 217 | return -ENOMEM; |
David Howells | 1a26feb | 2006-04-10 22:54:26 -0700 | [diff] [blame] | 218 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 219 | ret = install_process_keyring_to_cred(new); |
| 220 | if (ret < 0) { |
| 221 | abort_creds(new); |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 222 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
| 224 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 225 | return commit_creds(new); |
| 226 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | /* |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 229 | * Install the given keyring as the session keyring of the given credentials |
| 230 | * struct, replacing the existing one if any. If the given keyring is NULL, |
| 231 | * then install a new anonymous session keyring. |
Jann Horn | 5c7e372 | 2019-03-27 16:39:38 +0100 | [diff] [blame] | 232 | * @cred can not be in use by any task yet. |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 233 | * |
| 234 | * Return: 0 on success; -errno on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | */ |
Oleg Nesterov | 685bfd2 | 2010-05-26 14:43:00 -0700 | [diff] [blame] | 236 | int install_session_keyring_to_cred(struct cred *cred, struct key *keyring) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | { |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 238 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | struct key *old; |
David Howells | 1a26feb | 2006-04-10 22:54:26 -0700 | [diff] [blame] | 240 | |
| 241 | might_sleep(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | |
| 243 | /* create an empty session keyring */ |
| 244 | if (!keyring) { |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 245 | flags = KEY_ALLOC_QUOTA_OVERRUN; |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 246 | if (cred->session_keyring) |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 247 | flags = KEY_ALLOC_IN_QUOTA; |
| 248 | |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 249 | keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred, |
| 250 | KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, |
David Howells | 5ac7eac | 2016-04-06 16:14:24 +0100 | [diff] [blame] | 251 | flags, NULL, NULL); |
David Howells | 1a26feb | 2006-04-10 22:54:26 -0700 | [diff] [blame] | 252 | if (IS_ERR(keyring)) |
| 253 | return PTR_ERR(keyring); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 254 | } else { |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 255 | __key_get(keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | } |
| 257 | |
| 258 | /* install the keyring */ |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 259 | old = cred->session_keyring; |
Jann Horn | 5c7e372 | 2019-03-27 16:39:38 +0100 | [diff] [blame] | 260 | cred->session_keyring = keyring; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 262 | if (old) |
David Howells | 1a26feb | 2006-04-10 22:54:26 -0700 | [diff] [blame] | 263 | key_put(old); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | |
David Howells | 1a26feb | 2006-04-10 22:54:26 -0700 | [diff] [blame] | 265 | return 0; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 266 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | /* |
Eric Biggers | c9f838d | 2017-04-18 15:31:09 +0100 | [diff] [blame] | 269 | * Install the given keyring as the session keyring of the current task, |
| 270 | * replacing the existing one if any. If the given keyring is NULL, then |
| 271 | * install a new anonymous session keyring. |
| 272 | * |
| 273 | * Return: 0 on success; -errno on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 275 | static int install_session_keyring(struct key *keyring) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 277 | struct cred *new; |
| 278 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 280 | new = prepare_creds(); |
| 281 | if (!new) |
| 282 | return -ENOMEM; |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 283 | |
David Howells | 99599537 | 2011-08-22 14:08:33 +0100 | [diff] [blame] | 284 | ret = install_session_keyring_to_cred(new, keyring); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 285 | if (ret < 0) { |
| 286 | abort_creds(new); |
| 287 | return ret; |
| 288 | } |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 289 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 290 | return commit_creds(new); |
| 291 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 294 | * Handle the fsuid changing. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | */ |
David Howells | 2e21865 | 2019-05-22 14:06:51 +0100 | [diff] [blame] | 296 | void key_fsuid_changed(struct cred *new_cred) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | { |
| 298 | /* update the ownership of the thread keyring */ |
David Howells | 2e21865 | 2019-05-22 14:06:51 +0100 | [diff] [blame] | 299 | if (new_cred->thread_keyring) { |
| 300 | down_write(&new_cred->thread_keyring->sem); |
| 301 | new_cred->thread_keyring->uid = new_cred->fsuid; |
| 302 | up_write(&new_cred->thread_keyring->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 304 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 307 | * Handle the fsgid changing. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | */ |
David Howells | 2e21865 | 2019-05-22 14:06:51 +0100 | [diff] [blame] | 309 | void key_fsgid_changed(struct cred *new_cred) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | { |
| 311 | /* update the ownership of the thread keyring */ |
David Howells | 2e21865 | 2019-05-22 14:06:51 +0100 | [diff] [blame] | 312 | if (new_cred->thread_keyring) { |
| 313 | down_write(&new_cred->thread_keyring->sem); |
| 314 | new_cred->thread_keyring->gid = new_cred->fsgid; |
| 315 | up_write(&new_cred->thread_keyring->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 317 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 320 | * Search the process keyrings attached to the supplied cred for the first |
| 321 | * matching key. |
| 322 | * |
| 323 | * The search criteria are the type and the match function. The description is |
| 324 | * given to the match function as a parameter, but doesn't otherwise influence |
| 325 | * the search. Typically the match function will compare the description |
| 326 | * parameter to the key's description. |
| 327 | * |
| 328 | * This can only search keyrings that grant Search permission to the supplied |
| 329 | * credentials. Keyrings linked to searched keyrings will also be searched if |
| 330 | * they grant Search permission too. Keys can only be found if they grant |
| 331 | * Search permission to the credentials. |
| 332 | * |
| 333 | * Returns a pointer to the key with the key usage count incremented if |
| 334 | * successful, -EAGAIN if we didn't find any matching key or -ENOKEY if we only |
| 335 | * matched negative keys. |
| 336 | * |
| 337 | * In the case of a successful return, the possession attribute is set on the |
| 338 | * returned key reference. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | */ |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 340 | key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | { |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 342 | key_ref_t key_ref, ret, err; |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 343 | const struct cred *cred = ctx->cred; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | |
| 345 | /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were |
| 346 | * searchable, but we failed to find a key or we found a negative key; |
| 347 | * otherwise we want to return a sample error (probably -EACCES) if |
| 348 | * none of the keyrings were searchable |
| 349 | * |
| 350 | * in terms of priority: success > -ENOKEY > -EAGAIN > other error |
| 351 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 352 | key_ref = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | ret = NULL; |
| 354 | err = ERR_PTR(-EAGAIN); |
| 355 | |
| 356 | /* search the thread keyring first */ |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 357 | if (cred->thread_keyring) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 358 | key_ref = keyring_search_aux( |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 359 | make_key_ref(cred->thread_keyring, 1), ctx); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 360 | if (!IS_ERR(key_ref)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | goto found; |
| 362 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 363 | switch (PTR_ERR(key_ref)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | case -EAGAIN: /* no key */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | case -ENOKEY: /* negative key */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 366 | ret = key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | break; |
| 368 | default: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 369 | err = key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | break; |
| 371 | } |
| 372 | } |
| 373 | |
| 374 | /* search the process keyring second */ |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 375 | if (cred->process_keyring) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 376 | key_ref = keyring_search_aux( |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 377 | make_key_ref(cred->process_keyring, 1), ctx); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 378 | if (!IS_ERR(key_ref)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | goto found; |
| 380 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 381 | switch (PTR_ERR(key_ref)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | case -EAGAIN: /* no key */ |
David Howells | fe9453a | 2013-02-21 12:00:25 +0000 | [diff] [blame] | 383 | if (ret) |
| 384 | break; |
Mathieu Malaterre | 0f949bc | 2019-01-14 21:17:24 +0100 | [diff] [blame] | 385 | /* fall through */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | case -ENOKEY: /* negative key */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 387 | ret = key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | break; |
| 389 | default: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 390 | err = key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | break; |
| 392 | } |
| 393 | } |
| 394 | |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 395 | /* search the session keyring */ |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 396 | if (cred->session_keyring) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 397 | key_ref = keyring_search_aux( |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 398 | make_key_ref(cred->session_keyring, 1), ctx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 400 | if (!IS_ERR(key_ref)) |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 401 | goto found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 403 | switch (PTR_ERR(key_ref)) { |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 404 | case -EAGAIN: /* no key */ |
| 405 | if (ret) |
| 406 | break; |
Mathieu Malaterre | 0f949bc | 2019-01-14 21:17:24 +0100 | [diff] [blame] | 407 | /* fall through */ |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 408 | case -ENOKEY: /* negative key */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 409 | ret = key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | break; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 411 | default: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 412 | err = key_ref; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 413 | break; |
| 414 | } |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 415 | } |
| 416 | /* or search the user-session keyring */ |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 417 | else if (READ_ONCE(cred->user->session_keyring)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 418 | key_ref = keyring_search_aux( |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 419 | make_key_ref(READ_ONCE(cred->user->session_keyring), 1), |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 420 | ctx); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 421 | if (!IS_ERR(key_ref)) |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 422 | goto found; |
| 423 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 424 | switch (PTR_ERR(key_ref)) { |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 425 | case -EAGAIN: /* no key */ |
| 426 | if (ret) |
| 427 | break; |
Mathieu Malaterre | 0f949bc | 2019-01-14 21:17:24 +0100 | [diff] [blame] | 428 | /* fall through */ |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 429 | case -ENOKEY: /* negative key */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 430 | ret = key_ref; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 431 | break; |
| 432 | default: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 433 | err = key_ref; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 434 | break; |
| 435 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | } |
| 437 | |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 438 | /* no key - decide on the error we're going to go for */ |
| 439 | key_ref = ret ? ret : err; |
| 440 | |
| 441 | found: |
| 442 | return key_ref; |
| 443 | } |
| 444 | |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 445 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 446 | * Search the process keyrings attached to the supplied cred for the first |
| 447 | * matching key in the manner of search_my_process_keyrings(), but also search |
| 448 | * the keys attached to the assumed authorisation key using its credentials if |
| 449 | * one is available. |
| 450 | * |
| 451 | * Return same as search_my_process_keyrings(). |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 452 | */ |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 453 | key_ref_t search_process_keyrings(struct keyring_search_context *ctx) |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 454 | { |
| 455 | struct request_key_auth *rka; |
| 456 | key_ref_t key_ref, ret = ERR_PTR(-EACCES), err; |
| 457 | |
| 458 | might_sleep(); |
| 459 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 460 | key_ref = search_my_process_keyrings(ctx); |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 461 | if (!IS_ERR(key_ref)) |
| 462 | goto found; |
| 463 | err = key_ref; |
| 464 | |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 465 | /* if this process has an instantiation authorisation key, then we also |
| 466 | * search the keyrings of the process mentioned there |
| 467 | * - we don't permit access to request_key auth keys via this method |
| 468 | */ |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 469 | if (ctx->cred->request_key_auth && |
| 470 | ctx->cred == current_cred() && |
| 471 | ctx->index_key.type != &key_type_request_key_auth |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 472 | ) { |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 473 | const struct cred *cred = ctx->cred; |
| 474 | |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 475 | /* defend against the auth key being revoked */ |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 476 | down_read(&cred->request_key_auth->sem); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 477 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 478 | if (key_validate(ctx->cred->request_key_auth) == 0) { |
David Howells | 146aa8b | 2015-10-21 14:04:48 +0100 | [diff] [blame] | 479 | rka = ctx->cred->request_key_auth->payload.data[0]; |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 480 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 481 | ctx->cred = rka->cred; |
| 482 | key_ref = search_process_keyrings(ctx); |
| 483 | ctx->cred = cred; |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 484 | |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 485 | up_read(&cred->request_key_auth->sem); |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 486 | |
| 487 | if (!IS_ERR(key_ref)) |
| 488 | goto found; |
| 489 | |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 490 | ret = key_ref; |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 491 | } else { |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 492 | up_read(&cred->request_key_auth->sem); |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 493 | } |
| 494 | } |
| 495 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | /* no key - decide on the error we're going to go for */ |
David Howells | 927942a | 2010-06-11 17:31:10 +0100 | [diff] [blame] | 497 | if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY)) |
| 498 | key_ref = ERR_PTR(-ENOKEY); |
| 499 | else if (err == ERR_PTR(-EACCES)) |
| 500 | key_ref = ret; |
| 501 | else |
| 502 | key_ref = err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 504 | found: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 505 | return key_ref; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 506 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 509 | * See if the key we're looking at is the target key. |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 510 | */ |
David Howells | 0c903ab | 2014-09-16 17:36:08 +0100 | [diff] [blame] | 511 | bool lookup_user_key_possessed(const struct key *key, |
| 512 | const struct key_match_data *match_data) |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 513 | { |
David Howells | 4629195 | 2014-09-16 17:36:02 +0100 | [diff] [blame] | 514 | return key == match_data->raw_data; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 515 | } |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 516 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 517 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 518 | * Look up a key ID given us by userspace with a given permissions mask to get |
| 519 | * the key it refers to. |
| 520 | * |
| 521 | * Flags can be passed to request that special keyrings be created if referred |
| 522 | * to directly, to permit partially constructed keys to be found and to skip |
| 523 | * validity and permission checks on the found key. |
| 524 | * |
| 525 | * Returns a pointer to the key with an incremented usage count if successful; |
| 526 | * -EINVAL if the key ID is invalid; -ENOKEY if the key ID does not correspond |
| 527 | * to a key or the best found key was a negative key; -EKEYREVOKED or |
| 528 | * -EKEYEXPIRED if the best found key was revoked or expired; -EACCES if the |
| 529 | * found key doesn't grant the requested permit or the LSM denied access to it; |
| 530 | * or -ENOMEM if a special keyring couldn't be created. |
| 531 | * |
| 532 | * In the case of a successful return, the possession attribute is set on the |
| 533 | * returned key reference. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | */ |
David Howells | 5593122 | 2009-09-02 09:13:45 +0100 | [diff] [blame] | 535 | key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 536 | key_perm_t perm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | { |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 538 | struct keyring_search_context ctx = { |
David Howells | 4629195 | 2014-09-16 17:36:02 +0100 | [diff] [blame] | 539 | .match_data.cmp = lookup_user_key_possessed, |
| 540 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, |
| 541 | .flags = KEYRING_SEARCH_NO_STATE_CHECK, |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 542 | }; |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 543 | struct request_key_auth *rka; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | struct key *key; |
David Howells | b6dff3e | 2008-11-14 10:39:16 +1100 | [diff] [blame] | 545 | key_ref_t key_ref, skey_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | int ret; |
| 547 | |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 548 | try_again: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 549 | ctx.cred = get_current_cred(); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 550 | key_ref = ERR_PTR(-ENOKEY); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | |
| 552 | switch (id) { |
| 553 | case KEY_SPEC_THREAD_KEYRING: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 554 | if (!ctx.cred->thread_keyring) { |
David Howells | 5593122 | 2009-09-02 09:13:45 +0100 | [diff] [blame] | 555 | if (!(lflags & KEY_LOOKUP_CREATE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | goto error; |
| 557 | |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 558 | ret = install_thread_keyring(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | if (ret < 0) { |
Dan Carpenter | 4d09ec0 | 2010-05-17 14:42:35 +0100 | [diff] [blame] | 560 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | goto error; |
| 562 | } |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 563 | goto reget_creds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | } |
| 565 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 566 | key = ctx.cred->thread_keyring; |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 567 | __key_get(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 568 | key_ref = make_key_ref(key, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | break; |
| 570 | |
| 571 | case KEY_SPEC_PROCESS_KEYRING: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 572 | if (!ctx.cred->process_keyring) { |
David Howells | 5593122 | 2009-09-02 09:13:45 +0100 | [diff] [blame] | 573 | if (!(lflags & KEY_LOOKUP_CREATE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | goto error; |
| 575 | |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 576 | ret = install_process_keyring(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | if (ret < 0) { |
Dan Carpenter | 4d09ec0 | 2010-05-17 14:42:35 +0100 | [diff] [blame] | 578 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | goto error; |
| 580 | } |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 581 | goto reget_creds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | } |
| 583 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 584 | key = ctx.cred->process_keyring; |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 585 | __key_get(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 586 | key_ref = make_key_ref(key, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | break; |
| 588 | |
| 589 | case KEY_SPEC_SESSION_KEYRING: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 590 | if (!ctx.cred->session_keyring) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | /* always install a session keyring upon access if one |
| 592 | * doesn't exist yet */ |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 593 | ret = install_user_keyrings(); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 594 | if (ret < 0) |
| 595 | goto error; |
David Howells | 3ecf1b4 | 2011-08-22 14:08:43 +0100 | [diff] [blame] | 596 | if (lflags & KEY_LOOKUP_CREATE) |
| 597 | ret = join_session_keyring(NULL); |
| 598 | else |
| 599 | ret = install_session_keyring( |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 600 | ctx.cred->user->session_keyring); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 601 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | if (ret < 0) |
| 603 | goto error; |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 604 | goto reget_creds; |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 605 | } else if (ctx.cred->session_keyring == |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 606 | READ_ONCE(ctx.cred->user->session_keyring) && |
David Howells | 3ecf1b4 | 2011-08-22 14:08:43 +0100 | [diff] [blame] | 607 | lflags & KEY_LOOKUP_CREATE) { |
| 608 | ret = join_session_keyring(NULL); |
| 609 | if (ret < 0) |
| 610 | goto error; |
| 611 | goto reget_creds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | } |
| 613 | |
Jann Horn | 5c7e372 | 2019-03-27 16:39:38 +0100 | [diff] [blame] | 614 | key = ctx.cred->session_keyring; |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 615 | __key_get(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 616 | key_ref = make_key_ref(key, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | break; |
| 618 | |
| 619 | case KEY_SPEC_USER_KEYRING: |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 620 | if (!READ_ONCE(ctx.cred->user->uid_keyring)) { |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 621 | ret = install_user_keyrings(); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 622 | if (ret < 0) |
| 623 | goto error; |
| 624 | } |
| 625 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 626 | key = ctx.cred->user->uid_keyring; |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 627 | __key_get(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 628 | key_ref = make_key_ref(key, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | break; |
| 630 | |
| 631 | case KEY_SPEC_USER_SESSION_KEYRING: |
Jann Horn | 0b9dc6c | 2019-03-27 16:55:08 +0100 | [diff] [blame] | 632 | if (!READ_ONCE(ctx.cred->user->session_keyring)) { |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 633 | ret = install_user_keyrings(); |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 634 | if (ret < 0) |
| 635 | goto error; |
| 636 | } |
| 637 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 638 | key = ctx.cred->user->session_keyring; |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 639 | __key_get(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 640 | key_ref = make_key_ref(key, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | break; |
| 642 | |
| 643 | case KEY_SPEC_GROUP_KEYRING: |
| 644 | /* group keyrings are not yet supported */ |
Dan Carpenter | 4d09ec0 | 2010-05-17 14:42:35 +0100 | [diff] [blame] | 645 | key_ref = ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | goto error; |
| 647 | |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 648 | case KEY_SPEC_REQKEY_AUTH_KEY: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 649 | key = ctx.cred->request_key_auth; |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 650 | if (!key) |
| 651 | goto error; |
| 652 | |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 653 | __key_get(key); |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 654 | key_ref = make_key_ref(key, 1); |
| 655 | break; |
| 656 | |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 657 | case KEY_SPEC_REQUESTOR_KEYRING: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 658 | if (!ctx.cred->request_key_auth) |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 659 | goto error; |
| 660 | |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 661 | down_read(&ctx.cred->request_key_auth->sem); |
Dan Carpenter | f67dabb | 2012-03-06 13:32:16 +0000 | [diff] [blame] | 662 | if (test_bit(KEY_FLAG_REVOKED, |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 663 | &ctx.cred->request_key_auth->flags)) { |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 664 | key_ref = ERR_PTR(-EKEYREVOKED); |
| 665 | key = NULL; |
| 666 | } else { |
David Howells | 146aa8b | 2015-10-21 14:04:48 +0100 | [diff] [blame] | 667 | rka = ctx.cred->request_key_auth->payload.data[0]; |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 668 | key = rka->dest_keyring; |
David Howells | ccc3e6d | 2013-09-24 10:35:16 +0100 | [diff] [blame] | 669 | __key_get(key); |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 670 | } |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 671 | up_read(&ctx.cred->request_key_auth->sem); |
David Howells | 8bbf4976 | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 672 | if (!key) |
| 673 | goto error; |
| 674 | key_ref = make_key_ref(key, 1); |
| 675 | break; |
| 676 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | default: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 678 | key_ref = ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | if (id < 1) |
| 680 | goto error; |
| 681 | |
| 682 | key = key_lookup(id); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 683 | if (IS_ERR(key)) { |
David Howells | e231c2e | 2008-02-07 00:15:26 -0800 | [diff] [blame] | 684 | key_ref = ERR_CAST(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | goto error; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 686 | } |
| 687 | |
| 688 | key_ref = make_key_ref(key, 0); |
| 689 | |
| 690 | /* check to see if we possess the key */ |
Eric Biggers | 4754620 | 2019-05-29 14:01:52 -0700 | [diff] [blame^] | 691 | ctx.index_key = key->index_key; |
David Howells | 4629195 | 2014-09-16 17:36:02 +0100 | [diff] [blame] | 692 | ctx.match_data.raw_data = key; |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 693 | kdebug("check possessed"); |
| 694 | skey_ref = search_process_keyrings(&ctx); |
| 695 | kdebug("possessed=%p", skey_ref); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 696 | |
| 697 | if (!IS_ERR(skey_ref)) { |
| 698 | key_put(key); |
| 699 | key_ref = skey_ref; |
| 700 | } |
| 701 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | break; |
| 703 | } |
| 704 | |
David Howells | 5593122 | 2009-09-02 09:13:45 +0100 | [diff] [blame] | 705 | /* unlink does not use the nominated key in any way, so can skip all |
| 706 | * the permission checks as it is only concerned with the keyring */ |
| 707 | if (lflags & KEY_LOOKUP_FOR_UNLINK) { |
| 708 | ret = 0; |
| 709 | goto error; |
| 710 | } |
| 711 | |
| 712 | if (!(lflags & KEY_LOOKUP_PARTIAL)) { |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 713 | ret = wait_for_key_construction(key, true); |
| 714 | switch (ret) { |
| 715 | case -ERESTARTSYS: |
| 716 | goto invalid_key; |
| 717 | default: |
| 718 | if (perm) |
| 719 | goto invalid_key; |
| 720 | case 0: |
| 721 | break; |
| 722 | } |
| 723 | } else if (perm) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | ret = key_validate(key); |
| 725 | if (ret < 0) |
| 726 | goto invalid_key; |
| 727 | } |
| 728 | |
| 729 | ret = -EIO; |
David Howells | 5593122 | 2009-09-02 09:13:45 +0100 | [diff] [blame] | 730 | if (!(lflags & KEY_LOOKUP_PARTIAL) && |
David Howells | 363b02d | 2017-10-04 16:43:25 +0100 | [diff] [blame] | 731 | key_read_state(key) == KEY_IS_UNINSTANTIATED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | goto invalid_key; |
| 733 | |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 734 | /* check the permissions */ |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 735 | ret = key_task_permission(key_ref, ctx.cred, perm); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 736 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | goto invalid_key; |
| 738 | |
Baolin Wang | 074d589 | 2017-11-15 16:38:45 +0000 | [diff] [blame] | 739 | key->last_used_at = ktime_get_real_seconds(); |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 740 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 741 | error: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 742 | put_cred(ctx.cred); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 743 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 745 | invalid_key: |
| 746 | key_ref_put(key_ref); |
| 747 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | goto error; |
| 749 | |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 750 | /* if we attempted to install a keyring, then it may have caused new |
| 751 | * creds to be installed */ |
| 752 | reget_creds: |
David Howells | 4bdf0bc | 2013-09-24 10:35:15 +0100 | [diff] [blame] | 753 | put_cred(ctx.cred); |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 754 | goto try_again; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 755 | } |
Dave Jiang | 76ef5e1 | 2018-12-04 10:31:27 -0800 | [diff] [blame] | 756 | EXPORT_SYMBOL(lookup_user_key); |
David Howells | bb952bb | 2008-11-14 10:39:20 +1100 | [diff] [blame] | 757 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 759 | * Join the named keyring as the session keyring if possible else attempt to |
| 760 | * create a new one of that name and join that. |
| 761 | * |
| 762 | * If the name is NULL, an empty anonymous keyring will be installed as the |
| 763 | * session keyring. |
| 764 | * |
| 765 | * Named session keyrings are joined with a semaphore held to prevent the |
| 766 | * keyrings from going away whilst the attempt is made to going them and also |
| 767 | * to prevent a race in creating compatible session keyrings. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | */ |
| 769 | long join_session_keyring(const char *name) |
| 770 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 771 | const struct cred *old; |
| 772 | struct cred *new; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | struct key *keyring; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 774 | long ret, serial; |
| 775 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 776 | new = prepare_creds(); |
| 777 | if (!new) |
| 778 | return -ENOMEM; |
| 779 | old = current_cred(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | |
| 781 | /* if no name is provided, install an anonymous keyring */ |
| 782 | if (!name) { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 783 | ret = install_session_keyring_to_cred(new, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | if (ret < 0) |
| 785 | goto error; |
| 786 | |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 787 | serial = new->session_keyring->serial; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 788 | ret = commit_creds(new); |
| 789 | if (ret == 0) |
| 790 | ret = serial; |
| 791 | goto okay; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | } |
| 793 | |
| 794 | /* allow the user to join or create a named keyring */ |
Ingo Molnar | bb003079 | 2006-03-22 00:09:14 -0800 | [diff] [blame] | 795 | mutex_lock(&key_session_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | |
| 797 | /* look for an existing keyring of this name */ |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 798 | keyring = find_keyring_by_name(name, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | if (PTR_ERR(keyring) == -ENOKEY) { |
| 800 | /* not found - try and create a new one */ |
David Howells | 96b5c8f | 2012-10-02 19:24:56 +0100 | [diff] [blame] | 801 | keyring = keyring_alloc( |
| 802 | name, old->uid, old->gid, old, |
| 803 | KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK, |
David Howells | 5ac7eac | 2016-04-06 16:14:24 +0100 | [diff] [blame] | 804 | KEY_ALLOC_IN_QUOTA, NULL, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | if (IS_ERR(keyring)) { |
| 806 | ret = PTR_ERR(keyring); |
David Howells | bcf945d | 2005-08-04 13:07:06 -0700 | [diff] [blame] | 807 | goto error2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | } |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 809 | } else if (IS_ERR(keyring)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | ret = PTR_ERR(keyring); |
| 811 | goto error2; |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 812 | } else if (keyring == new->session_keyring) { |
| 813 | ret = 0; |
Eric Biggers | d636bd9 | 2017-06-08 14:48:03 +0100 | [diff] [blame] | 814 | goto error3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | } |
| 816 | |
| 817 | /* we've got a keyring - now to install it */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 818 | ret = install_session_keyring_to_cred(new, keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | if (ret < 0) |
Eric Biggers | d636bd9 | 2017-06-08 14:48:03 +0100 | [diff] [blame] | 820 | goto error3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 821 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 822 | commit_creds(new); |
| 823 | mutex_unlock(&key_session_mutex); |
| 824 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | ret = keyring->serial; |
| 826 | key_put(keyring); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 827 | okay: |
| 828 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | |
Eric Biggers | d636bd9 | 2017-06-08 14:48:03 +0100 | [diff] [blame] | 830 | error3: |
| 831 | key_put(keyring); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 832 | error2: |
Ingo Molnar | bb003079 | 2006-03-22 00:09:14 -0800 | [diff] [blame] | 833 | mutex_unlock(&key_session_mutex); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 834 | error: |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 835 | abort_creds(new); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | return ret; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 837 | } |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 838 | |
| 839 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 840 | * Replace a process's session keyring on behalf of one of its children when |
| 841 | * the target process is about to resume userspace execution. |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 842 | */ |
Al Viro | 67d1214 | 2012-06-27 11:07:19 +0400 | [diff] [blame] | 843 | void key_change_session_keyring(struct callback_head *twork) |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 844 | { |
Oleg Nesterov | 413cd3d | 2012-05-11 10:59:08 +1000 | [diff] [blame] | 845 | const struct cred *old = current_cred(); |
Al Viro | 67d1214 | 2012-06-27 11:07:19 +0400 | [diff] [blame] | 846 | struct cred *new = container_of(twork, struct cred, rcu); |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 847 | |
Oleg Nesterov | 413cd3d | 2012-05-11 10:59:08 +1000 | [diff] [blame] | 848 | if (unlikely(current->flags & PF_EXITING)) { |
| 849 | put_cred(new); |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 850 | return; |
Oleg Nesterov | 413cd3d | 2012-05-11 10:59:08 +1000 | [diff] [blame] | 851 | } |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 852 | |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 853 | new-> uid = old-> uid; |
| 854 | new-> euid = old-> euid; |
| 855 | new-> suid = old-> suid; |
| 856 | new->fsuid = old->fsuid; |
| 857 | new-> gid = old-> gid; |
| 858 | new-> egid = old-> egid; |
| 859 | new-> sgid = old-> sgid; |
| 860 | new->fsgid = old->fsgid; |
| 861 | new->user = get_uid(old->user); |
Eric W. Biederman | ba0e342 | 2013-03-02 19:14:03 -0800 | [diff] [blame] | 862 | new->user_ns = get_user_ns(old->user_ns); |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 863 | new->group_info = get_group_info(old->group_info); |
| 864 | |
| 865 | new->securebits = old->securebits; |
| 866 | new->cap_inheritable = old->cap_inheritable; |
| 867 | new->cap_permitted = old->cap_permitted; |
| 868 | new->cap_effective = old->cap_effective; |
Andy Lutomirski | 5831905 | 2015-09-04 15:42:45 -0700 | [diff] [blame] | 869 | new->cap_ambient = old->cap_ambient; |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 870 | new->cap_bset = old->cap_bset; |
| 871 | |
| 872 | new->jit_keyring = old->jit_keyring; |
| 873 | new->thread_keyring = key_get(old->thread_keyring); |
David Howells | 3a50597 | 2012-10-02 19:24:29 +0100 | [diff] [blame] | 874 | new->process_keyring = key_get(old->process_keyring); |
David Howells | ee18d64 | 2009-09-02 09:14:21 +0100 | [diff] [blame] | 875 | |
| 876 | security_transfer_creds(new, old); |
| 877 | |
| 878 | commit_creds(new); |
| 879 | } |
Mimi Zohar | c124bde | 2013-09-04 13:26:22 +0100 | [diff] [blame] | 880 | |
| 881 | /* |
| 882 | * Make sure that root's user and user-session keyrings exist. |
| 883 | */ |
| 884 | static int __init init_root_keyring(void) |
| 885 | { |
| 886 | return install_user_keyrings(); |
| 887 | } |
| 888 | |
| 889 | late_initcall(init_root_keyring); |