Blame view
security/keys/persistent.c
4.34 KB
b4d0d230c
|
1 |
// SPDX-License-Identifier: GPL-2.0-or-later |
f36f8c75a
|
2 3 4 5 |
/* General persistent per-UID keyrings register * * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) |
f36f8c75a
|
6 7 8 |
*/ #include <linux/user_namespace.h> |
5b825c3af
|
9 |
#include <linux/cred.h> |
f36f8c75a
|
10 11 12 13 14 15 16 17 18 19 20 21 22 23 |
#include "internal.h" unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */ /* * Create the persistent keyring register for the current user namespace. * * Called with the namespace's sem locked for writing. */ static int key_create_persistent_register(struct user_namespace *ns) { struct key *reg = keyring_alloc(".persistent_register", KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), |
028db3e29
|
24 25 |
((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ), |
5ac7eace2
|
26 |
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL); |
f36f8c75a
|
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 |
if (IS_ERR(reg)) return PTR_ERR(reg); ns->persistent_keyring_register = reg; return 0; } /* * Create the persistent keyring for the specified user. * * Called with the namespace's sem locked for writing. */ static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid, struct keyring_index_key *index_key) { struct key *persistent; key_ref_t reg_ref, persistent_ref; if (!ns->persistent_keyring_register) { long err = key_create_persistent_register(ns); if (err < 0) return ERR_PTR(err); } else { reg_ref = make_key_ref(ns->persistent_keyring_register, true); persistent_ref = find_key_to_update(reg_ref, index_key); if (persistent_ref) return persistent_ref; } persistent = keyring_alloc(index_key->description, uid, INVALID_GID, current_cred(), |
028db3e29
|
58 59 |
((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ), |
5ac7eace2
|
60 |
KEY_ALLOC_NOT_IN_QUOTA, NULL, |
f36f8c75a
|
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 |
ns->persistent_keyring_register); if (IS_ERR(persistent)) return ERR_CAST(persistent); return make_key_ref(persistent, true); } /* * Get the persistent keyring for a specific UID and link it to the nominated * keyring. */ static long key_get_persistent(struct user_namespace *ns, kuid_t uid, key_ref_t dest_ref) { struct keyring_index_key index_key; struct key *persistent; key_ref_t reg_ref, persistent_ref; char buf[32]; long ret; /* Look in the register if it exists */ |
3b6e4de05
|
82 |
memset(&index_key, 0, sizeof(index_key)); |
f36f8c75a
|
83 84 85 |
index_key.type = &key_type_keyring; index_key.description = buf; index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid)); |
f771fde82
|
86 |
key_set_index_key(&index_key); |
f36f8c75a
|
87 88 89 |
if (ns->persistent_keyring_register) { reg_ref = make_key_ref(ns->persistent_keyring_register, true); |
0f44e4d97
|
90 |
down_read(&ns->keyring_sem); |
f36f8c75a
|
91 |
persistent_ref = find_key_to_update(reg_ref, &index_key); |
0f44e4d97
|
92 |
up_read(&ns->keyring_sem); |
f36f8c75a
|
93 94 95 96 97 98 99 100 |
if (persistent_ref) goto found; } /* It wasn't in the register, so we'll need to create it. We might * also need to create the register. */ |
0f44e4d97
|
101 |
down_write(&ns->keyring_sem); |
f36f8c75a
|
102 |
persistent_ref = key_create_persistent(ns, uid, &index_key); |
0f44e4d97
|
103 |
up_write(&ns->keyring_sem); |
f36f8c75a
|
104 105 106 107 108 109 |
if (!IS_ERR(persistent_ref)) goto found; return PTR_ERR(persistent_ref); found: |
f5895943d
|
110 |
ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK); |
f36f8c75a
|
111 112 113 114 115 |
if (ret == 0) { persistent = key_ref_to_ptr(persistent_ref); ret = key_link(key_ref_to_ptr(dest_ref), persistent); if (ret == 0) { key_set_timeout(persistent, persistent_keyring_expiry); |
965475acc
|
116 |
ret = persistent->serial; |
f36f8c75a
|
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 |
} } key_ref_put(persistent_ref); return ret; } /* * Get the persistent keyring for a specific UID and link it to the nominated * keyring. */ long keyctl_get_persistent(uid_t _uid, key_serial_t destid) { struct user_namespace *ns = current_user_ns(); key_ref_t dest_ref; kuid_t uid; long ret; /* -1 indicates the current user */ if (_uid == (uid_t)-1) { uid = current_uid(); } else { uid = make_kuid(ns, _uid); if (!uid_valid(uid)) return -EINVAL; /* You can only see your own persistent cache if you're not * sufficiently privileged. */ |
fbf8c53f1
|
146 147 |
if (!uid_eq(uid, current_uid()) && !uid_eq(uid, current_euid()) && |
f36f8c75a
|
148 149 150 151 152 |
!ns_capable(ns, CAP_SETUID)) return -EPERM; } /* There must be a destination keyring */ |
f5895943d
|
153 |
dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
f36f8c75a
|
154 155 156 157 158 159 160 161 162 163 164 165 166 |
if (IS_ERR(dest_ref)) return PTR_ERR(dest_ref); if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) { ret = -ENOTDIR; goto out_put_dest; } ret = key_get_persistent(ns, uid, dest_ref); out_put_dest: key_ref_put(dest_ref); return ret; } |