diff options
Diffstat (limited to 'security/keys')
-rw-r--r-- | security/keys/Kconfig | 5 | ||||
-rw-r--r-- | security/keys/Makefile | 1 | ||||
-rw-r--r-- | security/keys/big_key.c | 143 | ||||
-rw-r--r-- | security/keys/encrypted-keys/Makefile | 1 | ||||
-rw-r--r-- | security/keys/encrypted-keys/encrypted.c | 9 | ||||
-rw-r--r-- | security/keys/encrypted-keys/encrypted.h | 1 | ||||
-rw-r--r-- | security/keys/gc.c | 8 | ||||
-rw-r--r-- | security/keys/internal.h | 2 | ||||
-rw-r--r-- | security/keys/key.c | 47 | ||||
-rw-r--r-- | security/keys/keyctl.c | 14 | ||||
-rw-r--r-- | security/keys/keyring.c | 86 | ||||
-rw-r--r-- | security/keys/permission.c | 7 | ||||
-rw-r--r-- | security/keys/proc.c | 39 | ||||
-rw-r--r-- | security/keys/process_keys.c | 8 | ||||
-rw-r--r-- | security/keys/request_key.c | 7 | ||||
-rw-r--r-- | security/keys/request_key_auth.c | 76 | ||||
-rw-r--r-- | security/keys/trusted.c | 25 | ||||
-rw-r--r-- | security/keys/trusted.h | 1 | ||||
-rw-r--r-- | security/keys/user_defined.c | 4 |
19 files changed, 254 insertions, 230 deletions
diff --git a/security/keys/Kconfig b/security/keys/Kconfig index a7a23b5541f8..6462e6654ccf 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -45,10 +45,9 @@ config BIG_KEYS bool "Large payload keys" depends on KEYS depends on TMPFS - depends on (CRYPTO_ANSI_CPRNG = y || CRYPTO_DRBG = y) + select CRYPTO select CRYPTO_AES - select CRYPTO_ECB - select CRYPTO_RNG + select CRYPTO_GCM help This option provides support for holding large keys within the kernel (for example Kerberos ticket caches). The data may be stored out to diff --git a/security/keys/Makefile b/security/keys/Makefile index 57dff0c15809..ef1581b337a3 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # # Makefile for key management # diff --git a/security/keys/big_key.c b/security/keys/big_key.c index 6acb00f6f22c..929e14978c42 100644 --- a/security/keys/big_key.c +++ b/security/keys/big_key.c @@ -1,5 +1,6 @@ /* Large capacity key type * + * Copyright (C) 2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * @@ -16,10 +17,10 @@ #include <linux/shmem_fs.h> #include <linux/err.h> #include <linux/scatterlist.h> +#include <linux/random.h> #include <keys/user-type.h> #include <keys/big_key-type.h> -#include <crypto/rng.h> -#include <crypto/skcipher.h> +#include <crypto/aead.h> /* * Layout of key payload words. @@ -49,7 +50,12 @@ enum big_key_op { /* * Key size for big_key data encryption */ -#define ENC_KEY_SIZE 16 +#define ENC_KEY_SIZE 32 + +/* + * Authentication tag length + */ +#define ENC_AUTHTAG_SIZE 16 /* * big_key defined keys take an arbitrary string as the description and an @@ -64,57 +70,62 @@ struct key_type key_type_big_key = { .destroy = big_key_destroy, .describe = big_key_describe, .read = big_key_read, + /* no ->update(); don't add it without changing big_key_crypt() nonce */ }; /* - * Crypto names for big_key data encryption + * Crypto names for big_key data authenticated encryption */ -static const char big_key_rng_name[] = "stdrng"; -static const char big_key_alg_name[] = "ecb(aes)"; +static const char big_key_alg_name[] = "gcm(aes)"; /* - * Crypto algorithms for big_key data encryption + * Crypto algorithms for big_key data authenticated encryption */ -static struct crypto_rng *big_key_rng; -static struct crypto_skcipher *big_key_skcipher; +static struct crypto_aead *big_key_aead; /* - * Generate random key to encrypt big_key data + * Since changing the key affects the entire object, we need a mutex. */ -static inline int big_key_gen_enckey(u8 *key) -{ - return crypto_rng_get_bytes(big_key_rng, key, ENC_KEY_SIZE); -} +static DEFINE_MUTEX(big_key_aead_lock); /* * Encrypt/decrypt big_key data */ static int big_key_crypt(enum big_key_op op, u8 *data, size_t datalen, u8 *key) { - int ret = -EINVAL; + int ret; struct scatterlist sgio; - SKCIPHER_REQUEST_ON_STACK(req, big_key_skcipher); - - if (crypto_skcipher_setkey(big_key_skcipher, key, ENC_KEY_SIZE)) { + struct aead_request *aead_req; + /* We always use a zero nonce. The reason we can get away with this is + * because we're using a different randomly generated key for every + * different encryption. Notably, too, key_type_big_key doesn't define + * an .update function, so there's no chance we'll wind up reusing the + * key to encrypt updated data. Simply put: one key, one encryption. + */ + u8 zero_nonce[crypto_aead_ivsize(big_key_aead)]; + + aead_req = aead_request_alloc(big_key_aead, GFP_KERNEL); + if (!aead_req) + return -ENOMEM; + + memset(zero_nonce, 0, sizeof(zero_nonce)); + sg_init_one(&sgio, data, datalen + (op == BIG_KEY_ENC ? ENC_AUTHTAG_SIZE : 0)); + aead_request_set_crypt(aead_req, &sgio, &sgio, datalen, zero_nonce); + aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); + aead_request_set_ad(aead_req, 0); + + mutex_lock(&big_key_aead_lock); + if (crypto_aead_setkey(big_key_aead, key, ENC_KEY_SIZE)) { ret = -EAGAIN; goto error; } - - skcipher_request_set_tfm(req, big_key_skcipher); - skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, - NULL, NULL); - - sg_init_one(&sgio, data, datalen); - skcipher_request_set_crypt(req, &sgio, &sgio, datalen, NULL); - if (op == BIG_KEY_ENC) - ret = crypto_skcipher_encrypt(req); + ret = crypto_aead_encrypt(aead_req); else - ret = crypto_skcipher_decrypt(req); - - skcipher_request_zero(req); - + ret = crypto_aead_decrypt(aead_req); error: + mutex_unlock(&big_key_aead_lock); + aead_request_free(aead_req); return ret; } @@ -146,16 +157,13 @@ int big_key_preparse(struct key_preparsed_payload *prep) * * File content is stored encrypted with randomly generated key. */ - size_t enclen = ALIGN(datalen, crypto_skcipher_blocksize(big_key_skcipher)); + size_t enclen = datalen + ENC_AUTHTAG_SIZE; loff_t pos = 0; - /* prepare aligned data to encrypt */ data = kmalloc(enclen, GFP_KERNEL); if (!data) return -ENOMEM; - memcpy(data, prep->data, datalen); - memset(data + datalen, 0x00, enclen - datalen); /* generate random key */ enckey = kmalloc(ENC_KEY_SIZE, GFP_KERNEL); @@ -163,13 +171,12 @@ int big_key_preparse(struct key_preparsed_payload *prep) ret = -ENOMEM; goto error; } - - ret = big_key_gen_enckey(enckey); - if (ret) + ret = get_random_bytes_wait(enckey, ENC_KEY_SIZE); + if (unlikely(ret)) goto err_enckey; /* encrypt aligned data */ - ret = big_key_crypt(BIG_KEY_ENC, data, enclen, enckey); + ret = big_key_crypt(BIG_KEY_ENC, data, datalen, enckey); if (ret) goto err_enckey; @@ -195,7 +202,7 @@ int big_key_preparse(struct key_preparsed_payload *prep) *path = file->f_path; path_get(path); fput(file); - kfree(data); + kzfree(data); } else { /* Just store the data in a buffer */ void *data = kmalloc(datalen, GFP_KERNEL); @@ -211,9 +218,9 @@ int big_key_preparse(struct key_preparsed_payload *prep) err_fput: fput(file); err_enckey: - kfree(enckey); + kzfree(enckey); error: - kfree(data); + kzfree(data); return ret; } @@ -227,7 +234,7 @@ void big_key_free_preparse(struct key_preparsed_payload *prep) path_put(path); } - kfree(prep->payload.data[big_key_data]); + kzfree(prep->payload.data[big_key_data]); } /* @@ -240,7 +247,7 @@ void big_key_revoke(struct key *key) /* clear the quota */ key_payload_reserve(key, 0); - if (key_is_instantiated(key) && + if (key_is_positive(key) && (size_t)key->payload.data[big_key_len] > BIG_KEY_FILE_THRESHOLD) vfs_truncate(path, 0); } @@ -259,7 +266,7 @@ void big_key_destroy(struct key *key) path->mnt = NULL; path->dentry = NULL; } - kfree(key->payload.data[big_key_data]); + kzfree(key->payload.data[big_key_data]); key->payload.data[big_key_data] = NULL; } @@ -272,7 +279,7 @@ void big_key_describe(const struct key *key, struct seq_file *m) seq_puts(m, key->description); - if (key_is_instantiated(key)) + if (key_is_positive(key)) seq_printf(m, ": %zu [%s]", datalen, datalen > BIG_KEY_FILE_THRESHOLD ? "file" : "buff"); @@ -295,7 +302,7 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen) struct file *file; u8 *data; u8 *enckey = (u8 *)key->payload.data[big_key_data]; - size_t enclen = ALIGN(datalen, crypto_skcipher_blocksize(big_key_skcipher)); + size_t enclen = datalen + ENC_AUTHTAG_SIZE; loff_t pos = 0; data = kmalloc(enclen, GFP_KERNEL); @@ -328,7 +335,7 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen) err_fput: fput(file); error: - kfree(data); + kzfree(data); } else { ret = datalen; if (copy_to_user(buffer, key->payload.data[big_key_data], @@ -344,47 +351,31 @@ error: */ static int __init big_key_init(void) { - struct crypto_skcipher *cipher; - struct crypto_rng *rng; int ret; - rng = crypto_alloc_rng(big_key_rng_name, 0, 0); - if (IS_ERR(rng)) { - pr_err("Can't alloc rng: %ld\n", PTR_ERR(rng)); - return PTR_ERR(rng); - } - - big_key_rng = rng; - - /* seed RNG */ - ret = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); - if (ret) { - pr_err("Can't reset rng: %d\n", ret); - goto error_rng; - } - /* init block cipher */ - cipher = crypto_alloc_skcipher(big_key_alg_name, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(cipher)) { - ret = PTR_ERR(cipher); + big_key_aead = crypto_alloc_aead(big_key_alg_name, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(big_key_aead)) { + ret = PTR_ERR(big_key_aead); pr_err("Can't alloc crypto: %d\n", ret); - goto error_rng; + return ret; + } + ret = crypto_aead_setauthsize(big_key_aead, ENC_AUTHTAG_SIZE); + if (ret < 0) { + pr_err("Can't set crypto auth tag len: %d\n", ret); + goto free_aead; } - - big_key_skcipher = cipher; ret = register_key_type(&key_type_big_key); if (ret < 0) { pr_err("Can't register type: %d\n", ret); - goto error_cipher; + goto free_aead; } return 0; -error_cipher: - crypto_free_skcipher(big_key_skcipher); -error_rng: - crypto_free_rng(big_key_rng); +free_aead: + crypto_free_aead(big_key_aead); return ret; } diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile index d6f8433250a5..7a44dce6f69d 100644 --- a/security/keys/encrypted-keys/Makefile +++ b/security/keys/encrypted-keys/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # # Makefile for encrypted keys # diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 69855ba0d3b3..d92cbf9687c3 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -309,6 +309,13 @@ static struct key *request_user_key(const char *master_desc, const u8 **master_k down_read(&ukey->sem); upayload = user_key_payload_locked(ukey); + if (!upayload) { + /* key was revoked before we acquired its semaphore */ + up_read(&ukey->sem); + key_put(ukey); + ukey = ERR_PTR(-EKEYREVOKED); + goto error; + } *master_key = upayload->data; *master_keylen = upayload->datalen; error: @@ -847,7 +854,7 @@ static int encrypted_update(struct key *key, struct key_preparsed_payload *prep) size_t datalen = prep->datalen; int ret = 0; - if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) + if (key_is_negative(key)) return -ENOKEY; if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; diff --git a/security/keys/encrypted-keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h index 47802c0de735..1809995db452 100644 --- a/security/keys/encrypted-keys/encrypted.h +++ b/security/keys/encrypted-keys/encrypted.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __ENCRYPTED_KEY_H #define __ENCRYPTED_KEY_H diff --git a/security/keys/gc.c b/security/keys/gc.c index 87cb260e4890..f01d48cb3de1 100644 --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -129,15 +129,15 @@ static noinline void key_gc_unused_keys(struct list_head *keys) while (!list_empty(keys)) { struct key *key = list_entry(keys->next, struct key, graveyard_link); + short state = key->state; + list_del(&key->graveyard_link); kdebug("- %u", key->serial); key_check(key); /* Throw away the key data if the key is instantiated */ - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags) && - !test_bit(KEY_FLAG_NEGATIVE, &key->flags) && - key->type->destroy) + if (state == KEY_IS_POSITIVE && key->type->destroy) key->type->destroy(key); security_key_free(key); @@ -151,7 +151,7 @@ static noinline void key_gc_unused_keys(struct list_head *keys) } atomic_dec(&key->user->nkeys); - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + if (state != KEY_IS_UNINSTANTIATED) atomic_dec(&key->user->nikeys); key_user_put(key->user); diff --git a/security/keys/internal.h b/security/keys/internal.h index 1c02c6547038..503adbae7b0d 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -141,7 +141,7 @@ extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx); extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx); -extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); +extern struct key *find_keyring_by_name(const char *name, bool uid_keyring); extern int install_user_keyrings(void); extern int install_thread_keyring_to_cred(struct cred *); diff --git a/security/keys/key.c b/security/keys/key.c index 83da68d98b40..83bf4b4afd49 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -54,10 +54,10 @@ void __key_check(const struct key *key) struct key_user *key_user_lookup(kuid_t uid) { struct key_user *candidate = NULL, *user; - struct rb_node *parent = NULL; - struct rb_node **p; + struct rb_node *parent, **p; try_again: + parent = NULL; p = &key_user_tree.rb_node; spin_lock(&key_user_lock); @@ -302,6 +302,8 @@ struct key *key_alloc(struct key_type *type, const char *desc, 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; #ifdef KEY_DEBUGGING key->magic = KEY_DEBUG_MAGIC; @@ -400,6 +402,18 @@ int key_payload_reserve(struct key *key, size_t datalen) 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 @@ -422,14 +436,14 @@ static int __key_instantiate_and_link(struct key *key, mutex_lock(&key_construction_mutex); /* can't instantiate twice */ - if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { + 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); - set_bit(KEY_FLAG_INSTANTIATED, &key->flags); + mark_key_instantiated(key, 0); if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; @@ -575,13 +589,10 @@ int key_reject_and_link(struct key *key, mutex_lock(&key_construction_mutex); /* can't instantiate twice */ - if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { + if (key->state == KEY_IS_UNINSTANTIATED) { /* mark the key as being negatively instantiated */ atomic_inc(&key->user->nikeys); - key->reject_error = -error; - smp_wmb(); - set_bit(KEY_FLAG_NEGATIVE, &key->flags); - set_bit(KEY_FLAG_INSTANTIATED, &key->flags); + mark_key_instantiated(key, -error); now = current_kernel_time(); key->expiry = now.tv_sec + timeout; key_schedule_gc(key->expiry + key_gc_delay); @@ -750,8 +761,8 @@ static inline key_ref_t __key_update(key_ref_t key_ref, ret = key->type->update(key, prep); if (ret == 0) - /* updating a negative key instantiates it */ - clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + /* Updating a negative key positively instantiates it */ + mark_key_instantiated(key, 0); up_write(&key->sem); @@ -934,6 +945,16 @@ error: */ __key_link_end(keyring, &index_key, edit); + key = key_ref_to_ptr(key_ref); + if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) { + ret = wait_for_key_construction(key, true); + if (ret < 0) { + key_ref_put(key_ref); + key_ref = ERR_PTR(ret); + goto error_free_prep; + } + } + key_ref = __key_update(key_ref, &prep); goto error_free_prep; } @@ -984,8 +1005,8 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen) ret = key->type->update(key, &prep); if (ret == 0) - /* updating a negative key instantiates it */ - clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + /* Updating a negative key positively instantiates it */ + mark_key_instantiated(key, 0); up_write(&key->sem); diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index ab0b337c84b4..76d22f726ae4 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -766,12 +766,16 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) key = key_ref_to_ptr(key_ref); + ret = key_read_state(key); + if (ret < 0) + goto error2; /* Negatively instantiated */ + /* see if we can read it directly */ ret = key_permission(key_ref, KEY_NEED_READ); if (ret == 0) goto can_read_key; if (ret != -EACCES) - goto error; + goto error2; /* we can't; see if it's searchable from this process's keyrings * - we automatically take account of the fact that it may be @@ -896,7 +900,7 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) atomic_dec(&key->user->nkeys); atomic_inc(&newowner->nkeys); - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { + if (key->state != KEY_IS_UNINSTANTIATED) { atomic_dec(&key->user->nikeys); atomic_inc(&newowner->nikeys); } @@ -1406,11 +1410,9 @@ long keyctl_assume_authority(key_serial_t id) } ret = keyctl_change_reqkey_auth(authkey); - if (ret < 0) - goto error; + if (ret == 0) + ret = authkey->serial; key_put(authkey); - - ret = authkey->serial; error: return ret; } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index de81793f9920..36f842ec87f0 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -414,7 +414,7 @@ static void keyring_describe(const struct key *keyring, struct seq_file *m) else seq_puts(m, "[anon]"); - if (key_is_instantiated(keyring)) { + if (key_is_positive(keyring)) { if (keyring->keys.nr_leaves_on_tree != 0) seq_printf(m, ": %lu", keyring->keys.nr_leaves_on_tree); else @@ -423,7 +423,7 @@ static void keyring_describe(const struct key *keyring, struct seq_file *m) } struct keyring_read_iterator_context { - size_t qty; + size_t buflen; size_t count; key_serial_t __user *buffer; }; @@ -435,9 +435,9 @@ static int keyring_read_iterator(const void *object, void *data) int ret; kenter("{%s,%d},,{%zu/%zu}", - key->type->name, key->serial, ctx->count, ctx->qty); + key->type->name, key->serial, ctx->count, ctx->buflen); - if (ctx->count >= ctx->qty) + if (ctx->count >= ctx->buflen) return 1; ret = put_user(key->serial, ctx->buffer); @@ -459,38 +459,33 @@ static long keyring_read(const struct key *keyring, char __user *buffer, size_t buflen) { struct keyring_read_iterator_context ctx; - unsigned long nr_keys; - int ret; + long ret; kenter("{%d},,%zu", key_serial(keyring), buflen); if (buflen & (sizeof(key_serial_t) - 1)) return -EINVAL; - nr_keys = keyring->keys.nr_leaves_on_tree; - if (nr_keys == 0) - return 0; - - /* Calculate how much data we could return */ - ctx.qty = nr_keys * sizeof(key_serial_t); - - if (!buffer || !buflen) - return ctx.qty; - - if (buflen > ctx.qty) - ctx.qty = buflen; - - /* Copy the IDs of the subscribed keys into the buffer */ - ctx.buffer = (key_serial_t __user *)buffer; - ctx.count = 0; - ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx); - if (ret < 0) { - kleave(" = %d [iterate]", ret); - return ret; + /* Copy as many key IDs as fit into the buffer */ + if (buffer && buflen) { + ctx.buffer = (key_serial_t __user *)buffer; + ctx.buflen = buflen; + ctx.count = 0; + ret = assoc_array_iterate(&keyring->keys, + keyring_read_iterator, &ctx); + if (ret < 0) { + kleave(" = %ld [iterate]", ret); + return ret; + } } - kleave(" = %zu [ok]", ctx.count); - return ctx.count; + /* Return the size of the buffer needed */ + ret = keyring->keys.nr_leaves_on_tree * sizeof(key_serial_t); + if (ret <= buflen) + kleave("= %ld [ok]", ret); + else + kleave("= %ld [buffer too small]", ret); + return ret; } /* @@ -557,7 +552,8 @@ static int keyring_search_iterator(const void *object, void *iterator_data) { struct keyring_search_context *ctx = iterator_data; const struct key *key = keyring_ptr_to_key(object); - unsigned long kflags = key->flags; + unsigned long kflags = READ_ONCE(key->flags); + short state = READ_ONCE(key->state); kenter("{%d}", key->serial); @@ -569,6 +565,8 @@ static int keyring_search_iterator(const void *object, void *iterator_data) /* skip invalidated, revoked and expired keys */ if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + time_t expiry = READ_ONCE(key->expiry); + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | (1 << KEY_FLAG_REVOKED))) { ctx->result = ERR_PTR(-EKEYREVOKED); @@ -576,7 +574,7 @@ static int keyring_search_iterator(const void *object, void *iterator_data) goto skipped; } - if (key->expiry && ctx->now.tv_sec >= key->expiry) { + if (expiry && ctx->now.tv_sec >= expiry) { if (!(ctx->flags & KEYRING_SEARCH_SKIP_EXPIRED)) ctx->result = ERR_PTR(-EKEYEXPIRED); kleave(" = %d [expire]", ctx->skipped_ret); @@ -601,9 +599,8 @@ static int keyring_search_iterator(const void *object, void *iterator_data) if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { /* we set a different error code if we pass a negative key */ - if (kflags & (1 << KEY_FLAG_NEGATIVE)) { - smp_rmb(); - ctx->result = ERR_PTR(key->reject_error); + if (state < 0) { + ctx->result = ERR_PTR(state); kleave(" = %d [neg]", ctx->skipped_ret); goto skipped; } @@ -1101,15 +1098,15 @@ found: /* * Find a keyring with the specified name. * - * All named keyrings in the current user namespace are searched, provided they - * grant Search permission directly to the caller (unless this check is - * skipped). Keyrings whose usage points have reached zero or who have been - * revoked are skipped. + * Only keyrings that have nonzero refcount, are not revoked, and are owned by a + * user in the current user namespace are considered. If @uid_keyring is %true, + * the keyring additionally must have been allocated as a user or user session + * keyring; otherwise, it must grant Search permission directly to the caller. * * Returns a pointer to the keyring with the keyring's refcount having being * incremented on success. -ENOKEY is returned if a key could not be found. */ -struct key *find_keyring_by_name(const char *name, bool skip_perm_check) +struct key *find_keyring_by_name(const char *name, bool uid_keyring) { struct key *keyring; int bucket; @@ -1137,10 +1134,15 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check) if (strcmp(keyring->description, name) != 0) continue; - if (!skip_perm_check && - key_permission(make_key_ref(keyring, 0), - KEY_NEED_SEARCH) < 0) - continue; + if (uid_keyring) { + if (!test_bit(KEY_FLAG_UID_KEYRING, + &keyring->flags)) + continue; + } else { + if (key_permission(make_key_ref(keyring, 0), + KEY_NEED_SEARCH) < 0) + continue; + } /* we've got a match but we might end up racing with * key_cleanup() if the keyring is currently 'dead' diff --git a/security/keys/permission.c b/security/keys/permission.c index 732cc0beffdf..a72b4dd70c8a 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -88,7 +88,8 @@ EXPORT_SYMBOL(key_task_permission); */ int key_validate(const struct key *key) { - unsigned long flags = key->flags; + unsigned long flags = READ_ONCE(key->flags); + time_t expiry = READ_ONCE(key->expiry); if (flags & (1 << KEY_FLAG_INVALIDATED)) return -ENOKEY; @@ -99,9 +100,9 @@ int key_validate(const struct key *key) return -EKEYREVOKED; /* check it hasn't expired */ - if (key->expiry) { + if (expiry) { struct timespec now = current_kernel_time(); - if (now.tv_sec >= key->expiry) + if (now.tv_sec >= expiry) return -EKEYEXPIRED; } diff --git a/security/keys/proc.c b/security/keys/proc.c index bf08d02b6646..6d1fcbba1e09 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -179,15 +179,18 @@ static int proc_keys_show(struct seq_file *m, void *v) struct rb_node *_p = v; struct key *key = rb_entry(_p, struct key, serial_node); struct timespec now; + time_t expiry; unsigned long timo; + unsigned long flags; key_ref_t key_ref, skey_ref; char xbuf[16]; + short state; int rc; struct keyring_search_context ctx = { .index_key.type = key->type, .index_key.description = key->description, - .cred = current_cred(), + .cred = m->file->f_cred, .match_data.cmp = lookup_user_key_possessed, .match_data.raw_data = key, .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, @@ -207,11 +210,7 @@ static int proc_keys_show(struct seq_file *m, void *v) } } - /* check whether the current task is allowed to view the key (assuming - * non-possession) - * - the caller holds a spinlock, and thus the RCU read lock, making our - * access to __current_cred() safe - */ + /* check whether the current task is allowed to view the key */ rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW); if (rc < 0) return 0; @@ -221,12 +220,13 @@ static int proc_keys_show(struct seq_file *m, void *v) rcu_read_lock(); /* come up with a suitable timeout value */ - if (key->expiry == 0) { + expiry = READ_ONCE(key->expiry); + if (expiry == 0) { memcpy(xbuf, "perm", 5); - } else if (now.tv_sec >= key->expiry) { + } else if (now.tv_sec >= expiry) { memcpy(xbuf, "expd", 5); } else { - timo = key->expiry - now.tv_sec; + timo = expiry - now.tv_sec; if (timo < 60) sprintf(xbuf, "%lus", timo); @@ -240,18 +240,21 @@ static int proc_keys_show(struct seq_file *m, void *v) sprintf(xbuf, "%luw", timo / (60*60*24*7)); } -#define showflag(KEY, LETTER, FLAG) \ - (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-') + state = key_read_state(key); + +#define showflag(FLAGS, LETTER, FLAG) \ + ((FLAGS & (1 << FLAG)) ? LETTER : '-') + flags = READ_ONCE(key->flags); seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", key->serial, - showflag(key, 'I', KEY_FLAG_INSTANTIATED), - showflag(key, 'R', KEY_FLAG_REVOKED), - showflag(key, 'D', KEY_FLAG_DEAD), - showflag(key, 'Q', KEY_FLAG_IN_QUOTA), - showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT), - showflag(key, 'N', KEY_FLAG_NEGATIVE), - showflag(key, 'i', KEY_FLAG_INVALIDATED), + state != KEY_IS_UNINSTANTIATED ? 'I' : '-', + showflag(flags, 'R', KEY_FLAG_REVOKED), + showflag(flags, 'D', KEY_FLAG_DEAD), + showflag(flags, 'Q', KEY_FLAG_IN_QUOTA), + showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT), + state < 0 ? 'N' : '-', + showflag(flags, 'i', KEY_FLAG_INVALIDATED), refcount_read(&key->usage), xbuf, key->perm, diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 86bced9fdbdf..740affd65ee9 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -77,7 +77,8 @@ int install_user_keyrings(void) if (IS_ERR(uid_keyring)) { uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID, cred, user_keyring_perm, - KEY_ALLOC_IN_QUOTA, + KEY_ALLOC_UID_KEYRING | + KEY_ALLOC_IN_QUOTA, NULL, NULL); if (IS_ERR(uid_keyring)) { ret = PTR_ERR(uid_keyring); @@ -94,7 +95,8 @@ int install_user_keyrings(void) session_keyring = keyring_alloc(buf, user->uid, INVALID_GID, cred, user_keyring_perm, - KEY_ALLOC_IN_QUOTA, + KEY_ALLOC_UID_KEYRING | + KEY_ALLOC_IN_QUOTA, NULL, NULL); if (IS_ERR(session_keyring)) { ret = PTR_ERR(session_keyring); @@ -728,7 +730,7 @@ try_again: ret = -EIO; if (!(lflags & KEY_LOOKUP_PARTIAL) && - !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + key_read_state(key) == KEY_IS_UNINSTANTIATED) goto invalid_key; /* check the permissions */ diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 63e63a42db3c..e8036cd0ad54 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -595,10 +595,9 @@ int wait_for_key_construction(struct key *key, bool intr) intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); if (ret) return -ERESTARTSYS; - if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { - smp_rmb(); - return key->reject_error; - } + ret = key_read_state(key); + if (ret < 0) + return ret; return key_validate(key); } EXPORT_SYMBOL(wait_for_key_construction); diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index afe9d22ab361..424e1d90412e 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -73,7 +73,7 @@ static void request_key_auth_describe(const struct key *key, seq_puts(m, "key:"); seq_puts(m, key->description); - if (key_is_instantiated(key)) + if (key_is_positive(key)) seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); } @@ -120,6 +120,18 @@ static void request_key_auth_revoke(struct key *key) } } +static void free_request_key_auth(struct request_key_auth *rka) +{ + if (!rka) + return; + key_put(rka->target_key); + key_put(rka->dest_keyring); + if (rka->cred) + put_cred(rka->cred); + kfree(rka->callout_info); + kfree(rka); +} + /* * Destroy an instantiation authorisation token key. */ @@ -129,15 +141,7 @@ static void request_key_auth_destroy(struct key *key) kenter("{%d}", key->serial); - if (rka->cred) { - put_cred(rka->cred); - rka->cred = NULL; - } - - key_put(rka->target_key); - key_put(rka->dest_keyring); - kfree(rka->callout_info); - kfree(rka); + free_request_key_auth(rka); } /* @@ -151,22 +155,18 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, const struct cred *cred = current->cred; struct key *authkey = NULL; char desc[20]; - int ret; + int ret = -ENOMEM; kenter("%d,", target->serial); /* allocate a auth record */ - rka = kmalloc(sizeof(*rka), GFP_KERNEL); - if (!rka) { - kleave(" = -ENOMEM"); - return ERR_PTR(-ENOMEM); - } - rka->callout_info = kmalloc(callout_len, GFP_KERNEL); - if (!rka->callout_info) { - kleave(" = -ENOMEM"); - kfree(rka); - return ERR_PTR(-ENOMEM); - } + rka = kzalloc(sizeof(*rka), GFP_KERNEL); + if (!rka) + goto error; + rka->callout_info = kmemdup(callout_info, callout_len, GFP_KERNEL); + if (!rka->callout_info) + goto error_free_rka; + rka->callout_len = callout_len; /* see if the calling process is already servicing the key request of * another process */ @@ -176,8 +176,12 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, /* if the auth key has been revoked, then the key we're * servicing is already instantiated */ - if (test_bit(KEY_FLAG_REVOKED, &cred->request_key_auth->flags)) - goto auth_key_revoked; + if (test_bit(KEY_FLAG_REVOKED, + &cred->request_key_auth->flags)) { + up_read(&cred->request_key_auth->sem); + ret = -EKEYREVOKED; + goto error_free_rka; + } irka = cred->request_key_auth->payload.data[0]; rka->cred = get_cred(irka->cred); @@ -193,8 +197,6 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, rka->target_key = key_get(target); rka->dest_keyring = key_get(dest_keyring); - memcpy(rka->callout_info, callout_info, callout_len); - rka->callout_len = callout_len; /* allocate the auth key */ sprintf(desc, "%x", target->serial); @@ -205,32 +207,22 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL); if (IS_ERR(authkey)) { ret = PTR_ERR(authkey); - goto error_alloc; + goto error_free_rka; } /* construct the auth key */ ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL); if (ret < 0) - goto error_inst; + goto error_put_authkey; kleave(" = {%d,%d}", authkey->serial, refcount_read(&authkey->usage)); return authkey; -auth_key_revoked: - up_read(&cred->request_key_auth->sem); - kfree(rka->callout_info); - kfree(rka); - kleave("= -EKEYREVOKED"); - return ERR_PTR(-EKEYREVOKED); - -error_inst: - key_revoke(authkey); +error_put_authkey: key_put(authkey); -error_alloc: - key_put(rka->target_key); - key_put(rka->dest_keyring); - kfree(rka->callout_info); - kfree(rka); +error_free_rka: + free_request_key_auth(rka); +error: kleave("= %d", ret); return ERR_PTR(ret); } diff --git a/security/keys/trusted.c b/security/keys/trusted.c index ddfaebf60fc8..98aa89ff7bfd 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -1066,7 +1066,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep) char *datablob; int ret = 0; - if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) + if (key_is_negative(key)) return -ENOKEY; p = key->payload.data[0]; if (!p->migratable) @@ -1147,20 +1147,21 @@ static long trusted_read(const struct key *key, char __user *buffer, p = dereference_key_locked(key); if (!p) return -EINVAL; - if (!buffer || buflen <= 0) - return 2 * p->blob_len; - ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); - if (!ascii_buf) - return -ENOMEM; - bufp = ascii_buf; - for (i = 0; i < p->blob_len; i++) - bufp = hex_byte_pack(bufp, p->blob[i]); - if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { + if (buffer && buflen >= 2 * p->blob_len) { + ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); + if (!ascii_buf) + return -ENOMEM; + + bufp = ascii_buf; + for (i = 0; i < p->blob_len; i++) + bufp = hex_byte_pack(bufp, p->blob[i]); + if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) { + kzfree(ascii_buf); + return -EFAULT; + } kzfree(ascii_buf); - return -EFAULT; } - kzfree(ascii_buf); return 2 * p->blob_len; } diff --git a/security/keys/trusted.h b/security/keys/trusted.h index ff001a5dcb24..8d5fe9eafb22 100644 --- a/security/keys/trusted.h +++ b/security/keys/trusted.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __TRUSTED_KEY_H #define __TRUSTED_KEY_H diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 3d8c68eba516..9f558bedba23 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -114,7 +114,7 @@ int user_update(struct key *key, struct key_preparsed_payload *prep) /* attach the new data, displacing the old */ key->expiry = prep->expiry; - if (!test_bit(KEY_FLAG_NEGATIVE, &key->flags)) + if (key_is_positive(key)) zap = dereference_key_locked(key); rcu_assign_keypointer(key, prep->payload.data[0]); prep->payload.data[0] = NULL; @@ -162,7 +162,7 @@ EXPORT_SYMBOL_GPL(user_destroy); void user_describe(const struct key *key, struct seq_file *m) { seq_puts(m, key->description); - if (key_is_instantiated(key)) + if (key_is_positive(key)) seq_printf(m, ": %u", key->datalen); } |