// SPDX-License-Identifier: GPL-2.0-or-later/* Basic authentication token and access key management * * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/export.h>#include <linux/init.h>#include <linux/poison.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/security.h>#include <linux/workqueue.h>#include <linux/random.h>#include <linux/err.h>#include "internal.h" struct kmem_cache *key_jar;struct rb_root key_serial_tree; /* tree of keys indexed by serial */DEFINE_SPINLOCK(key_serial_lock); struct rb_root key_user_tree; /* tree of quota records indexed by UID */DEFINE_SPINLOCK(key_user_lock); unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */unsigned int key_quota_maxkeys = 200; /* general key count quota */unsigned int key_quota_maxbytes = 20000; /* general key space quota */ static LIST_HEAD(key_types_list);static DECLARE_RWSEM(key_types_sem); /* We serialise key instantiation and link */DEFINE_MUTEX(key_construction_mutex); #ifdef KEY_DEBUGGINGvoid __key_check(const struct key *key){ printk("__key_check: key %p {%08x} should be {%08x}\n", key, key->magic, KEY_DEBUG_MAGIC); BUG();}#endif /* * Get the key quota record for a user, allocating a new record if one doesn't * already exist. */struct key_user *key_user_lookup(kuid_t uid){ struct key_user *candidate = NULL, *user; struct rb_node *parent, **p; try_again: parent = NULL; p = &key_user_tree.rb_node; spin_lock(&key_user_lock); /* search the tree for a user record with a matching UID */ while (*p) { parent = *p; user = rb_entry(parent, struct key_user, node); if (uid_lt(uid, user->uid)) p = &(*p)->rb_left; else if (uid_gt(uid, user->uid)) p = &(*p)->rb_right; else goto found; } /* if we get here, we failed to find a match in the tree */ if (!candidate) { /* allocate a candidate user record if we don't already have * one */ spin_unlock(&key_user_lock); user = NULL; candidate = kmalloc_obj(struct key_user); if (unlikely(!candidate)) goto out; /* the allocation may have scheduled, so we need to repeat the * search lest someone else added the record whilst we were * asleep */ goto try_again; } /* if we get here, then the user record still hadn't appeared on the * second pass - so we use the candidate record */ refcount_set(&candidate->usage, 1); atomic_set(&candidate->nkeys, 0); atomic_set(&candidate->nikeys, 0); candidate->uid = uid; candidate->qnkeys = 0; candidate->qnbytes = 0; spin_lock_init(&candidate->lock); mutex_init(&candidate->cons_lock); rb_link_node(&candidate->node, parent, p); rb_insert_color(&candidate->node, &key_user_tree); spin_unlock(&key_user_lock); user = candidate; goto out; /* okay - we found a user record for this UID */found: refcount_inc(&user->usage); spin_unlock(&key_user_lock); kfree(candidate);out: return user;} /* * Dispose of a user structure */void key_user_put(struct key_user *user){ if (refcount_dec_and_lock(&user->usage, &key_user_lock)) { rb_erase(&user->node, &key_user_tree); spin_unlock(&key_user_lock); kfree(user); }} /* * Allocate a serial number for a key. These are assigned randomly to avoid * security issues through covert channel problems. */static inline void key_alloc_serial(struct key *key){ struct rb_node *parent, **p; struct key *xkey; /* propose a random serial number and look for a hole for it in the * serial number tree */ do { get_random_bytes(&key->serial, sizeof(key->serial)); key->serial >>= 1; /* negative numbers are not permitted */ } while (key->serial < 3); spin_lock(&key_serial_lock); attempt_insertion: parent = NULL; p = &key_serial_tree.rb_node; while (*p) { parent = *p; xkey = rb_entry(parent, struct key, serial_node); if (key->serial < xkey->serial) p = &(*p)->rb_left; else if (key->serial > xkey->serial) p = &(*p)->rb_right; else goto serial_exists; } /* we've found a suitable hole - arrange for this key to occupy it */ rb_link_node(&key->serial_node, parent, p); rb_insert_color(&key->serial_node, &key_serial_tree); spin_unlock(&key_serial_lock); return; /* we found a key with the proposed serial number - walk the tree from * that point looking for the next unused serial number */serial_exists: for (;;) { key->serial++; if (key->serial < 3) { key->serial = 3; goto attempt_insertion; } parent = rb_next(parent); if (!parent) goto attempt_insertion; xkey = rb_entry(parent, struct key, serial_node); if (key->serial < xkey->serial) goto attempt_insertion; }} /** * key_alloc - Allocate a key of the specified type. * @type: The type of key to allocate. * @desc: The key description to allow the key to be searched out. * @uid: The owner of the new key. * @gid: The group ID for the new key's group permissions. * @cred: The credentials specifying UID namespace. * @perm: The permissions mask of the new key. * @flags: Flags specifying quota properties. * @restrict_link: Optional link restriction for new keyrings. * * Allocate a key of the specified type with the attributes given. The key is * returned in an uninstantiated state and the caller needs to instantiate the * key before returning. * * The restrict_link structure (if not NULL) will be freed when the * keyring is destroyed, so it must be dynamically allocated. * * The user's key count quota is updated to reflect the creation of the key and * the user's key data quota has the default for the key type reserved. The * instantiation function should amend this as necessary. If insufficient * quota is available, -EDQUOT will be returned. * * The LSM security modules can prevent a key being created, in which case * -EACCES will be returned. * * Returns a pointer to the new key if successful and an error code otherwise. * * Note that the caller needs to ensure the key type isn't uninstantiated. * Internally this can be done by locking key_types_sem. Externally, this can * be done by either never unregistering the key type, or making sure * key_alloc() calls don't race with module unloading. */struct key *key_alloc(struct key_type *type, const char *desc, kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags, struct key_restriction *restrict_link){ struct key_user *user = NULL; struct key *key; size_t desclen, quotalen; int ret; unsigned long irqflags; key = ERR_PTR(-EINVAL); if (!desc || !*desc) goto error; 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); 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_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock_irqsave(&user->lock, irqflags); if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { if (user->qnkeys + 1 > maxkeys || user->qnbytes + quotalen > maxbytes || user->qnbytes + quotalen < user->qnbytes) goto no_quota; } user->qnkeys++; user->qnbytes += quotalen; spin_unlock_irqrestore(&user->lock, irqflags); } /* allocate and initialise the key and its description */ key = kmem_cache_zalloc(key_jar, GFP_KERNEL); if (!key) goto no_memory_2; key->index_key.desc_len = desclen; key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); if (!key->index_key.description) goto no_memory_3; key->index_key.type = type; key_set_index_key(&key->index_key); refcount_set(&key->usage, 1); init_rwsem(&key->sem); lockdep_set_class(&key->sem, &type->lock_class); key->user = user; key->quotalen = quotalen; key->datalen = type->def_datalen; key->uid = uid; key->gid = gid; key->perm = perm; key->expiry = TIME64_MAX; key->restrict_link = restrict_link; key->last_used_at = ktime_get_real_seconds(); key->flags |= 1 << KEY_FLAG_USER_ALIVE; if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; if (flags & KEY_ALLOC_BUILT_IN) key->flags |= 1 << KEY_FLAG_BUILTIN; if (flags & KEY_ALLOC_UID_KEYRING) key->flags |= 1 << KEY_FLAG_UID_KEYRING; if (flags & KEY_ALLOC_SET_KEEP) key->flags |= 1 << KEY_FLAG_KEEP; #ifdef KEY_DEBUGGING key->magic = KEY_DEBUG_MAGIC;#endif /* let the security module know about the key */ ret = security_key_alloc(key, cred, flags); if (ret < 0) goto security_error; /* publish the key by giving it a serial number */ refcount_inc(&key->domain_tag->usage); atomic_inc(&user->nkeys); key_alloc_serial(key); error: return key; security_error: kfree(key->description); kmem_cache_free(key_jar, key); if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); key = ERR_PTR(ret); goto error; no_memory_3: kmem_cache_free(key_jar, key);no_memory_2: if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user);no_memory_1: key = ERR_PTR(-ENOMEM); goto error; no_quota: spin_unlock_irqrestore(&user->lock, irqflags); key_user_put(user); key = ERR_PTR(-EDQUOT); goto error;}EXPORT_SYMBOL(key_alloc); /** * key_payload_reserve - Adjust data quota reservation for the key's payload * @key: The key to make the reservation for. * @datalen: The amount of data payload the caller now wants. * * Adjust the amount of the owning user's key data quota that a key reserves. * If the amount is increased, then -EDQUOT may be returned if there isn't * enough free quota available. * * If successful, 0 is returned. */int key_payload_reserve(struct key *key, size_t datalen){ int delta = (int)datalen - key->datalen; int ret = 0; key_check(key); /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; unsigned long flags; spin_lock_irqsave(&key->user->lock, flags); if (delta > 0 && (key->user->qnbytes + delta > maxbytes || key->user->qnbytes + delta < key->user->qnbytes)) { ret = -EDQUOT; } else { key->user->qnbytes += delta; key->quotalen += delta; } spin_unlock_irqrestore(&key->user->lock, flags); } /* change the recorded data length if that didn't generate an error */ if (ret == 0) key->datalen = datalen; return ret;}EXPORT_SYMBOL(key_payload_reserve); /* * Change the key state to being instantiated. */static void mark_key_instantiated(struct key *key, int reject_error){ /* Commit the payload before setting the state; barrier versus * key_read_state(). */ smp_store_release(&key->state, (reject_error < 0) ? reject_error : KEY_IS_POSITIVE);} /* * Instantiate a key and link it into the target keyring atomically. Must be * called with the target keyring's semaphore writelocked. The target key's * semaphore need not be locked as instantiation is serialised by * key_construction_mutex. */static int __key_instantiate_and_link(struct key *key, struct key_preparsed_payload *prep, struct key *keyring, struct key *authkey, struct assoc_array_edit **_edit){ int ret, awaken; key_check(key); key_check(keyring); awaken = 0; ret = -EBUSY; mutex_lock(&key_construction_mutex); /* can't instantiate twice */ if (key->state == KEY_IS_UNINSTANTIATED) { /* instantiate the key */ ret = key->type->instantiate(key, prep); if (ret == 0) { /* mark the key as being instantiated */ atomic_inc(&key->user->nikeys); mark_key_instantiated(key, 0); notify_key(key, NOTIFY_KEY_INSTANTIATED, 0); if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; /* and link it into the destination keyring */ if (keyring) { if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) set_bit(KEY_FLAG_KEEP, &key->flags); __key_link(keyring, key, _edit); } /* disable the authorisation key */ if (authkey) key_invalidate(authkey); if (prep->expiry != TIME64_MAX) key_set_expiry(key, prep->expiry); } } mutex_unlock(&key_construction_mutex); /* wake up anyone waiting for a key to be constructed */ if (awaken) wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); return ret;} /** * key_instantiate_and_link - Instantiate a key and link it into the keyring. * @key: The key to instantiate. * @data: The data to use to instantiate the keyring. * @datalen: The length of @data. * @keyring: Keyring to create a link in on success (or NULL). * @authkey: The authorisation token permitting instantiation. * * Instantiate a key that's in the uninstantiated state using the provided data * and, if successful, link it in to the destination keyring if one is * supplied. * * 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_instantiate_and_link(struct key *key, const void *data,Lines 1–500 of 1293. Load more
// SPDX-License-Identifier: GPL-2.0-or-later /* Basic authentication token and access key management * * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/export.h> #include <linux/init.h> #include <linux/poison.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/security.h> #include <linux/workqueue.h> #include <linux/random.h> #include <linux/err.h> #include "internal.h" struct kmem_cache *key_jar; struct rb_root key_serial_tree; /* tree of keys indexed by serial */ DEFINE_SPINLOCK(key_serial_lock); struct rb_root key_user_tree; /* tree of quota records indexed by UID */ DEFINE_SPINLOCK(key_user_lock); unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */ unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */ unsigned int key_quota_maxkeys = 200; /* general key count quota */ unsigned int key_quota_maxbytes = 20000; /* general key space quota */ static LIST_HEAD(key_types_list); static DECLARE_RWSEM(key_types_sem); /* We serialise key instantiation and link */ DEFINE_MUTEX(key_construction_mutex); #ifdef KEY_DEBUGGING void __key_check(const struct key *key) { printk("__key_check: key %p {%08x} should be {%08x}\n", key, key->magic, KEY_DEBUG_MAGIC); BUG(); } #endif /* * Get the key quota record for a user, allocating a new record if one doesn't * already exist. */ struct key_user *key_user_lookup(kuid_t uid) { struct key_user *candidate = NULL, *user; struct rb_node *parent, **p; try_again: parent = NULL; p = &key_user_tree.rb_node; spin_lock(&key_user_lock); /* search the tree for a user record with a matching UID */ while (*p) { parent = *p; user = rb_entry(parent, struct key_user, node); if (uid_lt(uid, user->uid)) p = &(*p)->rb_left; else if (uid_gt(uid, user->uid)) p = &(*p)->rb_right; else goto found; } /* if we get here, we failed to find a match in the tree */ if (!candidate) { /* allocate a candidate user record if we don't already have * one */ spin_unlock(&key_user_lock); user = NULL; candidate = kmalloc_obj(struct key_user); if (unlikely(!candidate)) goto out; /* the allocation may have scheduled, so we need to repeat the * search lest someone else added the record whilst we were * asleep */ goto try_again; } /* if we get here, then the user record still hadn't appeared on the * second pass - so we use the candidate record */ refcount_set(&candidate->usage, 1); atomic_set(&candidate->nkeys, 0); atomic_set(&candidate->nikeys, 0); candidate->uid = uid; candidate->qnkeys = 0; candidate->qnbytes = 0; spin_lock_init(&candidate->lock); mutex_init(&candidate->cons_lock); rb_link_node(&candidate->node, parent, p); rb_insert_color(&candidate->node, &key_user_tree); spin_unlock(&key_user_lock); user = candidate; goto out; /* okay - we found a user record for this UID */ found: refcount_inc(&user->usage); spin_unlock(&key_user_lock); kfree(candidate); out: return user; } /* * Dispose of a user structure */ void key_user_put(struct key_user *user) { if (refcount_dec_and_lock(&user->usage, &key_user_lock)) { rb_erase(&user->node, &key_user_tree); spin_unlock(&key_user_lock); kfree(user); } } /* * Allocate a serial number for a key. These are assigned randomly to avoid * security issues through covert channel problems. */ static inline void key_alloc_serial(struct key *key) { struct rb_node *parent, **p; struct key *xkey; /* propose a random serial number and look for a hole for it in the * serial number tree */ do { get_random_bytes(&key->serial, sizeof(key->serial)); key->serial >>= 1; /* negative numbers are not permitted */ } while (key->serial < 3); spin_lock(&key_serial_lock); attempt_insertion: parent = NULL; p = &key_serial_tree.rb_node; while (*p) { parent = *p; xkey = rb_entry(parent, struct key, serial_node); if (key->serial < xkey->serial) p = &(*p)->rb_left; else if (key->serial > xkey->serial) p = &(*p)->rb_right; else goto serial_exists; } /* we've found a suitable hole - arrange for this key to occupy it */ rb_link_node(&key->serial_node, parent, p); rb_insert_color(&key->serial_node, &key_serial_tree); spin_unlock(&key_serial_lock); return; /* we found a key with the proposed serial number - walk the tree from * that point looking for the next unused serial number */ serial_exists: for (;;) { key->serial++; if (key->serial < 3) { key->serial = 3; goto attempt_insertion; } parent = rb_next(parent); if (!parent) goto attempt_insertion; xkey = rb_entry(parent, struct key, serial_node); if (key->serial < xkey->serial) goto attempt_insertion; } } /** * key_alloc - Allocate a key of the specified type. * @type: The type of key to allocate. * @desc: The key description to allow the key to be searched out. * @uid: The owner of the new key. * @gid: The group ID for the new key's group permissions. * @cred: The credentials specifying UID namespace. * @perm: The permissions mask of the new key. * @flags: Flags specifying quota properties. * @restrict_link: Optional link restriction for new keyrings. * * Allocate a key of the specified type with the attributes given. The key is * returned in an uninstantiated state and the caller needs to instantiate the * key before returning. * * The restrict_link structure (if not NULL) will be freed when the * keyring is destroyed, so it must be dynamically allocated. * * The user's key count quota is updated to reflect the creation of the key and * the user's key data quota has the default for the key type reserved. The * instantiation function should amend this as necessary. If insufficient * quota is available, -EDQUOT will be returned. * * The LSM security modules can prevent a key being created, in which case * -EACCES will be returned. * * Returns a pointer to the new key if successful and an error code otherwise. * * Note that the caller needs to ensure the key type isn't uninstantiated. * Internally this can be done by locking key_types_sem. Externally, this can * be done by either never unregistering the key type, or making sure * key_alloc() calls don't race with module unloading. */ struct key *key_alloc(struct key_type *type, const char *desc, kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags, struct key_restriction *restrict_link) { struct key_user *user = NULL; struct key *key; size_t desclen, quotalen; int ret; unsigned long irqflags; key = ERR_PTR(-EINVAL); if (!desc || !*desc) goto error; 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); 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_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock_irqsave(&user->lock, irqflags); if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { if (user->qnkeys + 1 > maxkeys || user->qnbytes + quotalen > maxbytes || user->qnbytes + quotalen < user->qnbytes) goto no_quota; } user->qnkeys++; user->qnbytes += quotalen; spin_unlock_irqrestore(&user->lock, irqflags); } /* allocate and initialise the key and its description */ key = kmem_cache_zalloc(key_jar, GFP_KERNEL); if (!key) goto no_memory_2; key->index_key.desc_len = desclen; key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); if (!key->index_key.description) goto no_memory_3; key->index_key.type = type; key_set_index_key(&key->index_key); refcount_set(&key->usage, 1); init_rwsem(&key->sem); lockdep_set_class(&key->sem, &type->lock_class); key->user = user; key->quotalen = quotalen; key->datalen = type->def_datalen; key->uid = uid; key->gid = gid; key->perm = perm; key->expiry = TIME64_MAX; key->restrict_link = restrict_link; key->last_used_at = ktime_get_real_seconds(); key->flags |= 1 << KEY_FLAG_USER_ALIVE; if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; if (flags & KEY_ALLOC_BUILT_IN) key->flags |= 1 << KEY_FLAG_BUILTIN; if (flags & KEY_ALLOC_UID_KEYRING) key->flags |= 1 << KEY_FLAG_UID_KEYRING; if (flags & KEY_ALLOC_SET_KEEP) key->flags |= 1 << KEY_FLAG_KEEP; #ifdef KEY_DEBUGGING key->magic = KEY_DEBUG_MAGIC; #endif /* let the security module know about the key */ ret = security_key_alloc(key, cred, flags); if (ret < 0) goto security_error; /* publish the key by giving it a serial number */ refcount_inc(&key->domain_tag->usage); atomic_inc(&user->nkeys); key_alloc_serial(key); error: return key; security_error: kfree(key->description); kmem_cache_free(key_jar, key); if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); key = ERR_PTR(ret); goto error; no_memory_3: kmem_cache_free(key_jar, key); no_memory_2: if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); no_memory_1: key = ERR_PTR(-ENOMEM); goto error; no_quota: spin_unlock_irqrestore(&user->lock, irqflags); key_user_put(user); key = ERR_PTR(-EDQUOT); goto error; } EXPORT_SYMBOL(key_alloc); /** * key_payload_reserve - Adjust data quota reservation for the key's payload * @key: The key to make the reservation for. * @datalen: The amount of data payload the caller now wants. * * Adjust the amount of the owning user's key data quota that a key reserves. * If the amount is increased, then -EDQUOT may be returned if there isn't * enough free quota available. * * If successful, 0 is returned. */ int key_payload_reserve(struct key *key, size_t datalen) { int delta = (int)datalen - key->datalen; int ret = 0; key_check(key); /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; unsigned long flags; spin_lock_irqsave(&key->user->lock, flags); if (delta > 0 && (key->user->qnbytes + delta > maxbytes || key->user->qnbytes + delta < key->user->qnbytes)) { ret = -EDQUOT; } else { key->user->qnbytes += delta; key->quotalen += delta; } spin_unlock_irqrestore(&key->user->lock, flags); } /* change the recorded data length if that didn't generate an error */ if (ret == 0) key->datalen = datalen; return ret; } EXPORT_SYMBOL(key_payload_reserve); /* * Change the key state to being instantiated. */ static void mark_key_instantiated(struct key *key, int reject_error) { /* Commit the payload before setting the state; barrier versus * key_read_state(). */ smp_store_release(&key->state, (reject_error < 0) ? reject_error : KEY_IS_POSITIVE); } /* * Instantiate a key and link it into the target keyring atomically. Must be * called with the target keyring's semaphore writelocked. The target key's * semaphore need not be locked as instantiation is serialised by * key_construction_mutex. */ static int __key_instantiate_and_link(struct key *key, struct key_preparsed_payload *prep, struct key *keyring, struct key *authkey, struct assoc_array_edit **_edit) { int ret, awaken; key_check(key); key_check(keyring); awaken = 0; ret = -EBUSY; mutex_lock(&key_construction_mutex); /* can't instantiate twice */ if (key->state == KEY_IS_UNINSTANTIATED) { /* instantiate the key */ ret = key->type->instantiate(key, prep); if (ret == 0) { /* mark the key as being instantiated */ atomic_inc(&key->user->nikeys); mark_key_instantiated(key, 0); notify_key(key, NOTIFY_KEY_INSTANTIATED, 0); if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; /* and link it into the destination keyring */ if (keyring) { if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) set_bit(KEY_FLAG_KEEP, &key->flags); __key_link(keyring, key, _edit); } /* disable the authorisation key */ if (authkey) key_invalidate(authkey); if (prep->expiry != TIME64_MAX) key_set_expiry(key, prep->expiry); } } mutex_unlock(&key_construction_mutex); /* wake up anyone waiting for a key to be constructed */ if (awaken) wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); return ret; } /** * key_instantiate_and_link - Instantiate a key and link it into the keyring. * @key: The key to instantiate. * @data: The data to use to instantiate the keyring. * @datalen: The length of @data. * @keyring: Keyring to create a link in on success (or NULL). * @authkey: The authorisation token permitting instantiation. * * Instantiate a key that's in the uninstantiated state using the provided data * and, if successful, link it in to the destination keyring if one is * supplied. * * 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_instantiate_and_link(struct key *key, const void *data,