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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208// SPDX-License-Identifier: GPL-2.0-or-later/* user_defined.c: user defined key type * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */
#include <linux/export.h>#include <linux/init.h>#include <linux/slab.h>#include <linux/seq_file.h>#include <linux/err.h>#include <keys/user-type.h>#include <linux/uaccess.h>#include "internal.h"
static int logon_vet_description(const char *desc);
/* * user defined keys take an arbitrary string as the description and an * arbitrary blob of data as the payload */struct key_type key_type_user = { .name = "user", .preparse = user_preparse, .free_preparse = user_free_preparse, .instantiate = generic_key_instantiate, .update = user_update, .revoke = user_revoke, .destroy = user_destroy, .describe = user_describe, .read = user_read,};
EXPORT_SYMBOL_GPL(key_type_user);
/* * This key type is essentially the same as key_type_user, but it does * not define a .read op. This is suitable for storing username and * password pairs in the keyring that you do not want to be readable * from userspace. */struct key_type key_type_logon = { .name = "logon", .preparse = user_preparse, .free_preparse = user_free_preparse, .instantiate = generic_key_instantiate, .update = user_update, .revoke = user_revoke, .destroy = user_destroy, .describe = user_describe, .vet_description = logon_vet_description,};EXPORT_SYMBOL_GPL(key_type_logon);
/* * Preparse a user defined key payload */int user_preparse(struct key_preparsed_payload *prep){ struct user_key_payload *upayload; size_t datalen = prep->datalen;
if (datalen == 0 || datalen > 32767 || !prep->data) return -EINVAL;
upayload = kmalloc_flex(*upayload, data, datalen); if (!upayload) return -ENOMEM;
/* attach the data */ prep->quotalen = datalen; prep->payload.data[0] = upayload; upayload->datalen = datalen; memcpy(upayload->data, prep->data, datalen); return 0;}EXPORT_SYMBOL_GPL(user_preparse);
/* * Free a preparse of a user defined key payload */void user_free_preparse(struct key_preparsed_payload *prep){ kfree_sensitive(prep->payload.data[0]);}EXPORT_SYMBOL_GPL(user_free_preparse);
static void user_free_payload_rcu(struct rcu_head *head){ struct user_key_payload *payload;
payload = container_of(head, struct user_key_payload, rcu); kfree_sensitive(payload);}
/* * update a user defined key * - the key's semaphore is write-locked */int user_update(struct key *key, struct key_preparsed_payload *prep){ struct user_key_payload *zap = NULL; int ret;
/* check the quota and attach the new data */ ret = key_payload_reserve(key, prep->datalen); if (ret < 0) return ret;
/* attach the new data, displacing the old */ key->expiry = prep->expiry; if (key_is_positive(key)) zap = dereference_key_locked(key); rcu_assign_keypointer(key, prep->payload.data[0]); prep->payload.data[0] = NULL;
if (zap) call_rcu(&zap->rcu, user_free_payload_rcu); return ret;}EXPORT_SYMBOL_GPL(user_update);
/* * dispose of the links from a revoked keyring * - called with the key sem write-locked */void user_revoke(struct key *key){ struct user_key_payload *upayload = user_key_payload_locked(key);
/* clear the quota */ key_payload_reserve(key, 0);
if (upayload) { rcu_assign_keypointer(key, NULL); call_rcu(&upayload->rcu, user_free_payload_rcu); }}
EXPORT_SYMBOL(user_revoke);
/* * dispose of the data dangling from the corpse of a user key */void user_destroy(struct key *key){ struct user_key_payload *upayload = key->payload.data[0];
kfree_sensitive(upayload);}
EXPORT_SYMBOL_GPL(user_destroy);
/* * describe the user key */void user_describe(const struct key *key, struct seq_file *m){ seq_puts(m, key->description); if (key_is_positive(key)) seq_printf(m, ": %u", key->datalen);}
EXPORT_SYMBOL_GPL(user_describe);
/* * read the key data * - the key's semaphore is read-locked */long user_read(const struct key *key, char *buffer, size_t buflen){ const struct user_key_payload *upayload; long ret;
upayload = user_key_payload_locked(key); ret = upayload->datalen;
/* we can return the data as is */ if (buffer && buflen > 0) { if (buflen > upayload->datalen) buflen = upayload->datalen;
memcpy(buffer, upayload->data, buflen); }
return ret;}
EXPORT_SYMBOL_GPL(user_read);
/* Vet the description for a "logon" key */static int logon_vet_description(const char *desc){ char *p;
/* require a "qualified" description string */ p = strchr(desc, ':'); if (!p) return -EINVAL;
/* also reject description with ':' as first char */ if (p == desc) return -EINVAL;
return 0;}