diff options
Diffstat (limited to 'security/keys/key.c')
| -rw-r--r-- | security/keys/key.c | 430 |
1 files changed, 213 insertions, 217 deletions
diff --git a/security/keys/key.c b/security/keys/key.c index 1c2d43dc510..2048a110e7f 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -18,10 +18,9 @@ #include <linux/workqueue.h> #include <linux/random.h> #include <linux/err.h> -#include <linux/user_namespace.h> #include "internal.h" -static struct kmem_cache *key_jar; +struct kmem_cache *key_jar; struct rb_root key_serial_tree; /* tree of keys indexed by serial */ DEFINE_SPINLOCK(key_serial_lock); @@ -36,17 +35,9 @@ unsigned int key_quota_maxbytes = 20000; /* general key space quota */ static LIST_HEAD(key_types_list); static DECLARE_RWSEM(key_types_sem); -static void key_cleanup(struct work_struct *work); -static DECLARE_WORK(key_cleanup_task, key_cleanup); - /* We serialise key instantiation and link */ DEFINE_MUTEX(key_construction_mutex); -/* Any key who's type gets unegistered will be re-typed to this */ -static struct key_type key_type_dead = { - .name = "dead", -}; - #ifdef KEY_DEBUGGING void __key_check(const struct key *key) { @@ -60,7 +51,7 @@ void __key_check(const struct key *key) * Get the key quota record for a user, allocating a new record if one doesn't * already exist. */ -struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns) +struct key_user *key_user_lookup(kuid_t uid) { struct key_user *candidate = NULL, *user; struct rb_node *parent = NULL; @@ -75,13 +66,9 @@ try_again: parent = *p; user = rb_entry(parent, struct key_user, node); - if (uid < user->uid) - p = &(*p)->rb_left; - else if (uid > user->uid) - p = &(*p)->rb_right; - else if (user_ns < user->user_ns) + if (uid_lt(uid, user->uid)) p = &(*p)->rb_left; - else if (user_ns > user->user_ns) + else if (uid_gt(uid, user->uid)) p = &(*p)->rb_right; else goto found; @@ -110,7 +97,6 @@ try_again: atomic_set(&candidate->nkeys, 0); atomic_set(&candidate->nikeys, 0); candidate->uid = uid; - candidate->user_ns = get_user_ns(user_ns); candidate->qnkeys = 0; candidate->qnbytes = 0; spin_lock_init(&candidate->lock); @@ -139,7 +125,6 @@ void key_user_put(struct key_user *user) if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { rb_erase(&user->node, &key_user_tree); spin_unlock(&key_user_lock); - put_user_ns(user->user_ns); kfree(user); } @@ -237,7 +222,7 @@ serial_exists: * key_alloc() calls don't race with module unloading. */ struct key *key_alloc(struct key_type *type, const char *desc, - uid_t uid, gid_t gid, const struct cred *cred, + kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags) { struct key_user *user = NULL; @@ -249,20 +234,28 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!desc || !*desc) goto error; - desclen = strlen(desc) + 1; - quotalen = desclen + type->def_datalen; + if (type->vet_description) { + ret = type->vet_description(desc); + if (ret < 0) { + key = ERR_PTR(ret); + goto error; + } + } + + desclen = strlen(desc); + quotalen = desclen + 1 + type->def_datalen; /* get hold of the key tracking for this user */ - user = key_user_lookup(uid, cred->user->user_ns); + user = key_user_lookup(uid); if (!user) goto no_memory_1; /* check that the user's quota permits allocation of another key and * its description */ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { - unsigned maxkeys = (uid == 0) ? + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (uid == 0) ? + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&user->lock); @@ -279,34 +272,32 @@ struct key *key_alloc(struct key_type *type, const char *desc, } /* allocate and initialise the key and its description */ - key = kmem_cache_alloc(key_jar, GFP_KERNEL); + key = kmem_cache_zalloc(key_jar, GFP_KERNEL); if (!key) goto no_memory_2; if (desc) { - key->description = kmemdup(desc, desclen, GFP_KERNEL); + key->index_key.desc_len = desclen; + key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); if (!key->description) goto no_memory_3; } atomic_set(&key->usage, 1); init_rwsem(&key->sem); - key->type = type; + lockdep_set_class(&key->sem, &type->lock_class); + key->index_key.type = type; key->user = user; key->quotalen = quotalen; key->datalen = type->def_datalen; key->uid = uid; key->gid = gid; key->perm = perm; - key->flags = 0; - key->expiry = 0; - key->payload.data = NULL; - key->security = NULL; if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; - - memset(&key->type_data, 0, sizeof(key->type_data)); + if (flags & KEY_ALLOC_TRUSTED) + key->flags |= 1 << KEY_FLAG_TRUSTED; #ifdef KEY_DEBUGGING key->magic = KEY_DEBUG_MAGIC; @@ -379,7 +370,7 @@ int key_payload_reserve(struct key *key, size_t datalen) /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - unsigned maxbytes = (key->user->uid == 0) ? + unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&key->user->lock); @@ -411,11 +402,10 @@ EXPORT_SYMBOL(key_payload_reserve); * key_construction_mutex. */ static int __key_instantiate_and_link(struct key *key, - const void *data, - size_t datalen, + struct key_preparsed_payload *prep, struct key *keyring, struct key *authkey, - unsigned long *_prealloc) + struct assoc_array_edit **_edit) { int ret, awaken; @@ -430,7 +420,7 @@ static int __key_instantiate_and_link(struct key *key, /* can't instantiate twice */ if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* instantiate the key */ - ret = key->type->instantiate(key, data, datalen); + ret = key->type->instantiate(key, prep); if (ret == 0) { /* mark the key as being instantiated */ @@ -442,7 +432,7 @@ static int __key_instantiate_and_link(struct key *key, /* and link it into the destination keyring */ if (keyring) - __key_link(keyring, key, _prealloc); + __key_link(key, _edit); /* disable the authorisation key */ if (authkey) @@ -481,52 +471,68 @@ int key_instantiate_and_link(struct key *key, struct key *keyring, struct key *authkey) { - unsigned long prealloc; + struct key_preparsed_payload prep; + struct assoc_array_edit *edit; int ret; + memset(&prep, 0, sizeof(prep)); + prep.data = data; + prep.datalen = datalen; + prep.quotalen = key->type->def_datalen; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; + } + if (keyring) { - ret = __key_link_begin(keyring, key->type, key->description, - &prealloc); + ret = __key_link_begin(keyring, &key->index_key, &edit); if (ret < 0) - return ret; + goto error_free_preparse; } - ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey, - &prealloc); + ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); if (keyring) - __key_link_end(keyring, key->type, prealloc); + __key_link_end(keyring, &key->index_key, edit); +error_free_preparse: + if (key->type->preparse) + key->type->free_preparse(&prep); +error: return ret; } EXPORT_SYMBOL(key_instantiate_and_link); /** - * key_negate_and_link - Negatively instantiate a key and link it into the keyring. + * key_reject_and_link - Negatively instantiate a key and link it into the keyring. * @key: The key to instantiate. * @timeout: The timeout on the negative key. + * @error: The error to return when the key is hit. * @keyring: Keyring to create a link in on success (or NULL). * @authkey: The authorisation token permitting instantiation. * * Negatively instantiate a key that's in the uninstantiated state and, if - * successful, set its timeout and link it in to the destination keyring if one - * is supplied. The key and any links to the key will be automatically garbage - * collected after the timeout expires. + * successful, set its timeout and stored error and link it in to the + * destination keyring if one is supplied. The key and any links to the key + * will be automatically garbage collected after the timeout expires. * * Negative keys are used to rate limit repeated request_key() calls by causing - * them to return -ENOKEY until the negative key expires. + * them to return the stored error code (typically ENOKEY) until the negative + * key expires. * * If successful, 0 is returned, the authorisation token is revoked and anyone * waiting for the key is woken up. If the key was already instantiated, * -EBUSY will be returned. */ -int key_negate_and_link(struct key *key, +int key_reject_and_link(struct key *key, unsigned timeout, + unsigned error, struct key *keyring, struct key *authkey) { - unsigned long prealloc; + struct assoc_array_edit *edit; struct timespec now; int ret, awaken, link_ret = 0; @@ -537,8 +543,7 @@ int key_negate_and_link(struct key *key, ret = -EBUSY; if (keyring) - link_ret = __key_link_begin(keyring, key->type, - key->description, &prealloc); + link_ret = __key_link_begin(keyring, &key->index_key, &edit); mutex_lock(&key_construction_mutex); @@ -546,6 +551,8 @@ int key_negate_and_link(struct key *key, if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* mark the key as being negatively instantiated */ atomic_inc(&key->user->nikeys); + key->type_data.reject_error = -error; + smp_wmb(); set_bit(KEY_FLAG_NEGATIVE, &key->flags); set_bit(KEY_FLAG_INSTANTIATED, &key->flags); now = current_kernel_time(); @@ -559,7 +566,7 @@ int key_negate_and_link(struct key *key, /* and link it into the destination keyring */ if (keyring && link_ret == 0) - __key_link(keyring, key, &prealloc); + __key_link(key, &edit); /* disable the authorisation key */ if (authkey) @@ -569,7 +576,7 @@ int key_negate_and_link(struct key *key, mutex_unlock(&key_construction_mutex); if (keyring) - __key_link_end(keyring, key->type, prealloc); + __key_link_end(keyring, &key->index_key, edit); /* wake up anyone waiting for a key to be constructed */ if (awaken) @@ -577,73 +584,7 @@ int key_negate_and_link(struct key *key, return ret == 0 ? link_ret : ret; } - -EXPORT_SYMBOL(key_negate_and_link); - -/* - * Garbage collect keys in process context so that we don't have to disable - * interrupts all over the place. - * - * key_put() schedules this rather than trying to do the cleanup itself, which - * means key_put() doesn't have to sleep. - */ -static void key_cleanup(struct work_struct *work) -{ - struct rb_node *_n; - struct key *key; - -go_again: - /* look for a dead key in the tree */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (atomic_read(&key->usage) == 0) - goto found_dead_key; - } - - spin_unlock(&key_serial_lock); - return; - -found_dead_key: - /* we found a dead key - once we've removed it from the tree, we can - * drop the lock */ - rb_erase(&key->serial_node, &key_serial_tree); - spin_unlock(&key_serial_lock); - - key_check(key); - - security_key_free(key); - - /* deal with the user's key tracking and quota */ - if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - spin_lock(&key->user->lock); - key->user->qnkeys--; - key->user->qnbytes -= key->quotalen; - spin_unlock(&key->user->lock); - } - - atomic_dec(&key->user->nkeys); - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) - atomic_dec(&key->user->nikeys); - - key_user_put(key->user); - - /* now throw away the key memory */ - if (key->type->destroy) - key->type->destroy(key); - - kfree(key->description); - -#ifdef KEY_DEBUGGING - key->magic = KEY_DEBUG_MAGIC_X; -#endif - kmem_cache_free(key_jar, key); - - /* there may, of course, be more than one key to destroy */ - goto go_again; -} +EXPORT_SYMBOL(key_reject_and_link); /** * key_put - Discard a reference to a key. @@ -659,7 +600,7 @@ void key_put(struct key *key) key_check(key); if (atomic_dec_and_test(&key->usage)) - schedule_work(&key_cleanup_task); + schedule_work(&key_gc_work); } } EXPORT_SYMBOL(key_put); @@ -699,7 +640,7 @@ found: /* this races with key_put(), but that doesn't matter since key_put() * doesn't actually change the key */ - atomic_inc(&key->usage); + __key_get(key); error: spin_unlock(&key_serial_lock); @@ -732,6 +673,26 @@ found_kernel_type: return ktype; } +void key_set_timeout(struct key *key, unsigned timeout) +{ + struct timespec now; + time_t expiry = 0; + + /* make the changes with the locks held to prevent races */ + down_write(&key->sem); + + if (timeout > 0) { + now = current_kernel_time(); + expiry = now.tv_sec + timeout; + } + + key->expiry = expiry; + key_schedule_gc(key->expiry + key_gc_delay); + + up_write(&key->sem); +} +EXPORT_SYMBOL_GPL(key_set_timeout); + /* * Unlock a key type locked by key_type_lookup(). */ @@ -747,13 +708,13 @@ void key_type_put(struct key_type *ktype) * if we get an error. */ static inline key_ref_t __key_update(key_ref_t key_ref, - const void *payload, size_t plen) + struct key_preparsed_payload *prep) { struct key *key = key_ref_to_ptr(key_ref); int ret; /* need write permission on the key to update it */ - ret = key_permission(key_ref, KEY_WRITE); + ret = key_permission(key_ref, KEY_NEED_WRITE); if (ret < 0) goto error; @@ -763,7 +724,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref, down_write(&key->sem); - ret = key->type->update(key, payload, plen); + ret = key->type->update(key, prep); if (ret == 0) /* updating a negative key instantiates it */ clear_bit(KEY_FLAG_NEGATIVE, &key->flags); @@ -814,24 +775,28 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, key_perm_t perm, unsigned long flags) { - unsigned long prealloc; + struct keyring_index_key index_key = { + .description = description, + }; + struct key_preparsed_payload prep; + struct assoc_array_edit *edit; const struct cred *cred = current_cred(); - struct key_type *ktype; struct key *keyring, *key = NULL; key_ref_t key_ref; int ret; /* look up the key type to see if it's one of the registered kernel * types */ - ktype = key_type_lookup(type); - if (IS_ERR(ktype)) { + index_key.type = key_type_lookup(type); + if (IS_ERR(index_key.type)) { key_ref = ERR_PTR(-ENODEV); goto error; } key_ref = ERR_PTR(-EINVAL); - if (!ktype->match || !ktype->instantiate) - goto error_2; + if (!index_key.type->match || !index_key.type->instantiate || + (!index_key.description && !index_key.type->preparse)) + goto error_put_type; keyring = key_ref_to_ptr(keyring_ref); @@ -839,78 +804,105 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, key_ref = ERR_PTR(-ENOTDIR); if (keyring->type != &key_type_keyring) - goto error_2; + goto error_put_type; + + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = index_key.type->def_datalen; + prep.trusted = flags & KEY_ALLOC_TRUSTED; + if (index_key.type->preparse) { + ret = index_key.type->preparse(&prep); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_put_type; + } + if (!index_key.description) + index_key.description = prep.description; + key_ref = ERR_PTR(-EINVAL); + if (!index_key.description) + goto error_free_prep; + } + index_key.desc_len = strlen(index_key.description); - ret = __key_link_begin(keyring, ktype, description, &prealloc); - if (ret < 0) - goto error_2; + key_ref = ERR_PTR(-EPERM); + if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags)) + goto error_free_prep; + flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0; + + ret = __key_link_begin(keyring, &index_key, &edit); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_free_prep; + } /* if we're going to allocate a new key, we're going to have * to modify the keyring */ - ret = key_permission(keyring_ref, KEY_WRITE); + ret = key_permission(keyring_ref, KEY_NEED_WRITE); if (ret < 0) { key_ref = ERR_PTR(ret); - goto error_3; + goto error_link_end; } /* if it's possible to update this type of key, search for an existing * key of the same type and description in the destination keyring and * update that instead if possible */ - if (ktype->update) { - key_ref = __keyring_search_one(keyring_ref, ktype, description, - 0); - if (!IS_ERR(key_ref)) + if (index_key.type->update) { + key_ref = find_key_to_update(keyring_ref, &index_key); + if (key_ref) goto found_matching_key; } /* if the client doesn't provide, decide on the permissions we want */ if (perm == KEY_PERM_UNDEF) { perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; - perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; + perm |= KEY_USR_VIEW; - if (ktype->read) - perm |= KEY_POS_READ | KEY_USR_READ; + if (index_key.type->read) + perm |= KEY_POS_READ; - if (ktype == &key_type_keyring || ktype->update) - perm |= KEY_USR_WRITE; + if (index_key.type == &key_type_keyring || + index_key.type->update) + perm |= KEY_POS_WRITE; } /* allocate a new key */ - key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred, - perm, flags); + key = key_alloc(index_key.type, index_key.description, + cred->fsuid, cred->fsgid, cred, perm, flags); if (IS_ERR(key)) { key_ref = ERR_CAST(key); - goto error_3; + goto error_link_end; } /* instantiate it and link it into the target keyring */ - ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL, - &prealloc); + ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); if (ret < 0) { key_put(key); key_ref = ERR_PTR(ret); - goto error_3; + goto error_link_end; } key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); - error_3: - __key_link_end(keyring, ktype, prealloc); - error_2: - key_type_put(ktype); - error: +error_link_end: + __key_link_end(keyring, &index_key, edit); +error_free_prep: + if (index_key.type->preparse) + index_key.type->free_preparse(&prep); +error_put_type: + key_type_put(index_key.type); +error: return key_ref; found_matching_key: /* we found a matching key, so we're going to try to update it * - we can drop the locks first as we have the key pinned */ - __key_link_end(keyring, ktype, prealloc); - key_type_put(ktype); + __key_link_end(keyring, &index_key, edit); - key_ref = __key_update(key_ref, payload, plen); - goto error; + key_ref = __key_update(key_ref, &prep); + goto error_free_prep; } EXPORT_SYMBOL(key_create_or_update); @@ -929,30 +921,44 @@ EXPORT_SYMBOL(key_create_or_update); */ int key_update(key_ref_t key_ref, const void *payload, size_t plen) { + struct key_preparsed_payload prep; struct key *key = key_ref_to_ptr(key_ref); int ret; key_check(key); /* the key must be writable */ - ret = key_permission(key_ref, KEY_WRITE); + ret = key_permission(key_ref, KEY_NEED_WRITE); if (ret < 0) goto error; /* attempt to update it if supported */ ret = -EOPNOTSUPP; - if (key->type->update) { - down_write(&key->sem); - - ret = key->type->update(key, payload, plen); - if (ret == 0) - /* updating a negative key instantiates it */ - clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + if (!key->type->update) + goto error; - up_write(&key->sem); + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = key->type->def_datalen; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; } - error: + down_write(&key->sem); + + ret = key->type->update(key, &prep); + if (ret == 0) + /* updating a negative key instantiates it */ + clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + + up_write(&key->sem); + + if (key->type->preparse) + key->type->free_preparse(&prep); +error: return ret; } EXPORT_SYMBOL(key_update); @@ -996,6 +1002,28 @@ void key_revoke(struct key *key) EXPORT_SYMBOL(key_revoke); /** + * key_invalidate - Invalidate a key. + * @key: The key to be invalidated. + * + * Mark a key as being invalidated and have it cleaned up immediately. The key + * is ignored by all searches and other operations from this point. + */ +void key_invalidate(struct key *key) +{ + kenter("%d", key_serial(key)); + + key_check(key); + + if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + down_write_nested(&key->sem, 1); + if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) + key_schedule_gc_links(); + up_write(&key->sem); + } +} +EXPORT_SYMBOL(key_invalidate); + +/** * register_key_type - Register a type of key. * @ktype: The new key type. * @@ -1008,6 +1036,8 @@ int register_key_type(struct key_type *ktype) struct key_type *p; int ret; + memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); + ret = -EEXIST; down_write(&key_types_sem); @@ -1019,6 +1049,8 @@ int register_key_type(struct key_type *ktype) /* store the type */ list_add(&ktype->link, &key_types_list); + + pr_notice("Key type %s registered\n", ktype->name); ret = 0; out: @@ -1037,49 +1069,12 @@ EXPORT_SYMBOL(register_key_type); */ void unregister_key_type(struct key_type *ktype) { - struct rb_node *_n; - struct key *key; - down_write(&key_types_sem); - - /* withdraw the key type */ list_del_init(&ktype->link); - - /* mark all the keys of this type dead */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (key->type == ktype) { - key->type = &key_type_dead; - set_bit(KEY_FLAG_DEAD, &key->flags); - } - } - - spin_unlock(&key_serial_lock); - - /* make sure everyone revalidates their keys */ - synchronize_rcu(); - - /* we should now be able to destroy the payloads of all the keys of - * this type with impunity */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (key->type == ktype) { - if (ktype->destroy) - ktype->destroy(key); - memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); - } - } - - spin_unlock(&key_serial_lock); - up_write(&key_types_sem); - - key_schedule_gc(0); + downgrade_write(&key_types_sem); + key_gc_keytype(ktype); + pr_notice("Key type %s unregistered\n", ktype->name); + up_read(&key_types_sem); } EXPORT_SYMBOL(unregister_key_type); @@ -1096,6 +1091,7 @@ void __init key_init(void) list_add_tail(&key_type_keyring.link, &key_types_list); list_add_tail(&key_type_dead.link, &key_types_list); list_add_tail(&key_type_user.link, &key_types_list); + list_add_tail(&key_type_logon.link, &key_types_list); /* record the root user tracking */ rb_link_node(&root_key_user.node, |
