diff options
Diffstat (limited to 'security/keys')
| -rw-r--r-- | security/keys/Kconfig | 13 | ||||
| -rw-r--r-- | security/keys/big_key.c | 257 | ||||
| -rw-r--r-- | security/keys/compat.c | 3 | ||||
| -rw-r--r-- | security/keys/gc.c | 5 | ||||
| -rw-r--r-- | security/keys/internal.h | 49 | ||||
| -rw-r--r-- | security/keys/key.c | 38 | ||||
| -rw-r--r-- | security/keys/keyctl.c | 133 | ||||
| -rw-r--r-- | security/keys/keyring.c | 20 | ||||
| -rw-r--r-- | security/keys/permission.c | 31 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 46 | ||||
| -rw-r--r-- | security/keys/request_key.c | 4 |
11 files changed, 298 insertions, 301 deletions
diff --git a/security/keys/Kconfig b/security/keys/Kconfig index 47c041563d41..83bc23409164 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -60,9 +60,7 @@ config BIG_KEYS bool "Large payload keys" depends on KEYS depends on TMPFS - select CRYPTO - select CRYPTO_AES - select CRYPTO_GCM + depends on CRYPTO_LIB_CHACHA20POLY1305 = y help This option provides support for holding large keys within the kernel (for example Kerberos ticket caches). The data may be stored out to @@ -116,3 +114,12 @@ config KEY_DH_OPERATIONS in the kernel. If you are unsure as to whether this is required, answer N. + +config KEY_NOTIFICATIONS + bool "Provide key/keyring change notifications" + depends on KEYS && WATCH_QUEUE + help + This option provides support for getting change notifications on keys + and keyrings on which the caller has View permission. This makes use + of the /dev/watch_queue misc device to handle the notification + buffer and provides KEYCTL_WATCH_KEY to enable/disable watches. diff --git a/security/keys/big_key.c b/security/keys/big_key.c index 82008f900930..dd708e8f13c0 100644 --- a/security/keys/big_key.c +++ b/security/keys/big_key.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* Large capacity key type * - * Copyright (C) 2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * Copyright (C) 2017-2020 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) */ @@ -12,20 +12,10 @@ #include <linux/file.h> #include <linux/shmem_fs.h> #include <linux/err.h> -#include <linux/scatterlist.h> #include <linux/random.h> -#include <linux/vmalloc.h> #include <keys/user-type.h> #include <keys/big_key-type.h> -#include <crypto/aead.h> -#include <crypto/gcm.h> - -struct big_key_buf { - unsigned int nr_pages; - void *virt; - struct scatterlist *sg; - struct page *pages[]; -}; +#include <crypto/chacha20poly1305.h> /* * Layout of key payload words. @@ -38,14 +28,6 @@ enum { }; /* - * Crypto operation with big_key data - */ -enum big_key_op { - BIG_KEY_ENC, - BIG_KEY_DEC, -}; - -/* * If the data is under this limit, there's no point creating a shm file to * hold it as the permanently resident metadata for the shmem fs will be at * least as large as the data. @@ -53,16 +35,6 @@ enum big_key_op { #define BIG_KEY_FILE_THRESHOLD (sizeof(struct inode) + sizeof(struct dentry)) /* - * Key size for big_key data encryption - */ -#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 * arbitrary blob of data as the payload */ @@ -75,136 +47,20 @@ 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 */ + .update = big_key_update, }; /* - * Crypto names for big_key data authenticated encryption - */ -static const char big_key_alg_name[] = "gcm(aes)"; -#define BIG_KEY_IV_SIZE GCM_AES_IV_SIZE - -/* - * Crypto algorithms for big_key data authenticated encryption - */ -static struct crypto_aead *big_key_aead; - -/* - * Since changing the key affects the entire object, we need a mutex. - */ -static DEFINE_MUTEX(big_key_aead_lock); - -/* - * Encrypt/decrypt big_key data - */ -static int big_key_crypt(enum big_key_op op, struct big_key_buf *buf, size_t datalen, u8 *key) -{ - int ret; - 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[BIG_KEY_IV_SIZE]; - - aead_req = aead_request_alloc(big_key_aead, GFP_KERNEL); - if (!aead_req) - return -ENOMEM; - - memset(zero_nonce, 0, sizeof(zero_nonce)); - aead_request_set_crypt(aead_req, buf->sg, buf->sg, 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; - } - if (op == BIG_KEY_ENC) - ret = crypto_aead_encrypt(aead_req); - else - ret = crypto_aead_decrypt(aead_req); -error: - mutex_unlock(&big_key_aead_lock); - aead_request_free(aead_req); - return ret; -} - -/* - * Free up the buffer. - */ -static void big_key_free_buffer(struct big_key_buf *buf) -{ - unsigned int i; - - if (buf->virt) { - memset(buf->virt, 0, buf->nr_pages * PAGE_SIZE); - vunmap(buf->virt); - } - - for (i = 0; i < buf->nr_pages; i++) - if (buf->pages[i]) - __free_page(buf->pages[i]); - - kfree(buf); -} - -/* - * Allocate a buffer consisting of a set of pages with a virtual mapping - * applied over them. - */ -static void *big_key_alloc_buffer(size_t len) -{ - struct big_key_buf *buf; - unsigned int npg = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; - unsigned int i, l; - - buf = kzalloc(sizeof(struct big_key_buf) + - sizeof(struct page) * npg + - sizeof(struct scatterlist) * npg, - GFP_KERNEL); - if (!buf) - return NULL; - - buf->nr_pages = npg; - buf->sg = (void *)(buf->pages + npg); - sg_init_table(buf->sg, npg); - - for (i = 0; i < buf->nr_pages; i++) { - buf->pages[i] = alloc_page(GFP_KERNEL); - if (!buf->pages[i]) - goto nomem; - - l = min_t(size_t, len, PAGE_SIZE); - sg_set_page(&buf->sg[i], buf->pages[i], l, 0); - len -= l; - } - - buf->virt = vmap(buf->pages, buf->nr_pages, VM_MAP, PAGE_KERNEL); - if (!buf->virt) - goto nomem; - - return buf; - -nomem: - big_key_free_buffer(buf); - return NULL; -} - -/* * Preparse a big key */ int big_key_preparse(struct key_preparsed_payload *prep) { - struct big_key_buf *buf; struct path *path = (struct path *)&prep->payload.data[big_key_path]; struct file *file; - u8 *enckey; + u8 *buf, *enckey; ssize_t written; - size_t datalen = prep->datalen, enclen = datalen + ENC_AUTHTAG_SIZE; + size_t datalen = prep->datalen; + size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE; int ret; if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data) @@ -220,28 +76,28 @@ int big_key_preparse(struct key_preparsed_payload *prep) * to be swapped out if needed. * * File content is stored encrypted with randomly generated key. + * Since the key is random for each file, we can set the nonce + * to zero, provided we never define a ->update() call. */ loff_t pos = 0; - buf = big_key_alloc_buffer(enclen); + buf = kvmalloc(enclen, GFP_KERNEL); if (!buf) return -ENOMEM; - memcpy(buf->virt, prep->data, datalen); /* generate random key */ - enckey = kmalloc(ENC_KEY_SIZE, GFP_KERNEL); + enckey = kmalloc(CHACHA20POLY1305_KEY_SIZE, GFP_KERNEL); if (!enckey) { ret = -ENOMEM; goto error; } - ret = get_random_bytes_wait(enckey, ENC_KEY_SIZE); + ret = get_random_bytes_wait(enckey, CHACHA20POLY1305_KEY_SIZE); if (unlikely(ret)) goto err_enckey; - /* encrypt aligned data */ - ret = big_key_crypt(BIG_KEY_ENC, buf, datalen, enckey); - if (ret) - goto err_enckey; + /* encrypt data */ + chacha20poly1305_encrypt(buf, prep->data, datalen, NULL, 0, + 0, enckey); /* save aligned data to file */ file = shmem_kernel_file_setup("", enclen, 0); @@ -250,11 +106,11 @@ int big_key_preparse(struct key_preparsed_payload *prep) goto err_enckey; } - written = kernel_write(file, buf->virt, enclen, &pos); + written = kernel_write(file, buf, enclen, &pos); if (written != enclen) { ret = written; if (written >= 0) - ret = -ENOMEM; + ret = -EIO; goto err_fput; } @@ -265,7 +121,8 @@ int big_key_preparse(struct key_preparsed_payload *prep) *path = file->f_path; path_get(path); fput(file); - big_key_free_buffer(buf); + memzero_explicit(buf, enclen); + kvfree(buf); } else { /* Just store the data in a buffer */ void *data = kmalloc(datalen, GFP_KERNEL); @@ -283,7 +140,8 @@ err_fput: err_enckey: kzfree(enckey); error: - big_key_free_buffer(buf); + memzero_explicit(buf, enclen); + kvfree(buf); return ret; } @@ -334,6 +192,23 @@ void big_key_destroy(struct key *key) } /* + * Update a big key + */ +int big_key_update(struct key *key, struct key_preparsed_payload *prep) +{ + int ret; + + ret = key_payload_reserve(key, prep->datalen); + if (ret < 0) + return ret; + + if (key_is_positive(key)) + big_key_destroy(key); + + return generic_key_instantiate(key, prep); +} + +/* * describe the big_key key */ void big_key_describe(const struct key *key, struct seq_file *m) @@ -361,14 +236,13 @@ long big_key_read(const struct key *key, char *buffer, size_t buflen) return datalen; if (datalen > BIG_KEY_FILE_THRESHOLD) { - struct big_key_buf *buf; struct path *path = (struct path *)&key->payload.data[big_key_path]; struct file *file; - u8 *enckey = (u8 *)key->payload.data[big_key_data]; - size_t enclen = datalen + ENC_AUTHTAG_SIZE; + u8 *buf, *enckey = (u8 *)key->payload.data[big_key_data]; + size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE; loff_t pos = 0; - buf = big_key_alloc_buffer(enclen); + buf = kvmalloc(enclen, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -379,25 +253,28 @@ long big_key_read(const struct key *key, char *buffer, size_t buflen) } /* read file to kernel and decrypt */ - ret = kernel_read(file, buf->virt, enclen, &pos); - if (ret >= 0 && ret != enclen) { - ret = -EIO; + ret = kernel_read(file, buf, enclen, &pos); + if (ret != enclen) { + if (ret >= 0) + ret = -EIO; goto err_fput; } - ret = big_key_crypt(BIG_KEY_DEC, buf, enclen, enckey); - if (ret) + ret = chacha20poly1305_decrypt(buf, buf, enclen, NULL, 0, 0, + enckey) ? 0 : -EBADMSG; + if (unlikely(ret)) goto err_fput; ret = datalen; /* copy out decrypted data */ - memcpy(buffer, buf->virt, datalen); + memcpy(buffer, buf, datalen); err_fput: fput(file); error: - big_key_free_buffer(buf); + memzero_explicit(buf, enclen); + kvfree(buf); } else { ret = datalen; memcpy(buffer, key->payload.data[big_key_data], datalen); @@ -411,39 +288,7 @@ error: */ static int __init big_key_init(void) { - int ret; - - /* init block 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); - return ret; - } - - if (unlikely(crypto_aead_ivsize(big_key_aead) != BIG_KEY_IV_SIZE)) { - WARN(1, "big key algorithm changed?"); - ret = -EINVAL; - goto free_aead; - } - - 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; - } - - ret = register_key_type(&key_type_big_key); - if (ret < 0) { - pr_err("Can't register type: %d\n", ret); - goto free_aead; - } - - return 0; - -free_aead: - crypto_free_aead(big_key_aead); - return ret; + return register_key_type(&key_type_big_key); } late_initcall(big_key_init); diff --git a/security/keys/compat.c b/security/keys/compat.c index b975f8f11124..6ee9d8f6a4a5 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -156,6 +156,9 @@ COMPAT_SYSCALL_DEFINE5(keyctl, u32, option, case KEYCTL_CAPABILITIES: return keyctl_capabilities(compat_ptr(arg2), arg3); + case KEYCTL_WATCH_KEY: + return keyctl_watch_key(arg2, arg3, arg4); + default: return -EOPNOTSUPP; } diff --git a/security/keys/gc.c b/security/keys/gc.c index 671dd730ecfc..3c90807476eb 100644 --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -131,6 +131,11 @@ static noinline void key_gc_unused_keys(struct list_head *keys) kdebug("- %u", key->serial); key_check(key); +#ifdef CONFIG_KEY_NOTIFICATIONS + remove_watch_list(key->watchers, key->serial); + key->watchers = NULL; +#endif + /* Throw away the key data if the key is instantiated */ if (state == KEY_IS_POSITIVE && key->type->destroy) key->type->destroy(key); diff --git a/security/keys/internal.h b/security/keys/internal.h index 6d0ca48ae9a5..338a526cbfa5 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -15,6 +15,7 @@ #include <linux/task_work.h> #include <linux/keyctl.h> #include <linux/refcount.h> +#include <linux/watch_queue.h> #include <linux/compat.h> #include <linux/mm.h> #include <linux/vmalloc.h> @@ -99,7 +100,8 @@ extern int __key_link_begin(struct key *keyring, const struct keyring_index_key *index_key, struct assoc_array_edit **_edit); extern int __key_link_check_live_key(struct key *keyring, struct key *key); -extern void __key_link(struct key *key, struct assoc_array_edit **_edit); +extern void __key_link(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit); extern void __key_link_end(struct key *keyring, const struct keyring_index_key *index_key, struct assoc_array_edit *edit); @@ -165,7 +167,6 @@ extern bool lookup_user_key_possessed(const struct key *key, const struct key_match_data *match_data); #define KEY_LOOKUP_CREATE 0x01 #define KEY_LOOKUP_PARTIAL 0x02 -#define KEY_LOOKUP_FOR_UNLINK 0x04 extern long join_session_keyring(const char *name); extern void key_change_session_keyring(struct callback_head *twork); @@ -181,14 +182,32 @@ extern void key_gc_keytype(struct key_type *ktype); extern int key_task_permission(const key_ref_t key_ref, const struct cred *cred, - key_perm_t perm); + enum key_need_perm need_perm); + +static inline void notify_key(struct key *key, + enum key_notification_subtype subtype, u32 aux) +{ +#ifdef CONFIG_KEY_NOTIFICATIONS + struct key_notification n = { + .watch.type = WATCH_TYPE_KEY_NOTIFY, + .watch.subtype = subtype, + .watch.info = watch_sizeof(n), + .key_id = key_serial(key), + .aux = aux, + }; + + post_watch_notification(key->watchers, &n.watch, current_cred(), + n.key_id); +#endif +} /* * Check to see whether permission is granted to use a key in the desired way. */ -static inline int key_permission(const key_ref_t key_ref, unsigned perm) +static inline int key_permission(const key_ref_t key_ref, + enum key_need_perm need_perm) { - return key_task_permission(key_ref, current_cred(), perm); + return key_task_permission(key_ref, current_cred(), need_perm); } extern struct key_type key_type_request_key_auth; @@ -333,6 +352,15 @@ static inline long keyctl_pkey_e_d_s(int op, extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen); +#ifdef CONFIG_KEY_NOTIFICATIONS +extern long keyctl_watch_key(key_serial_t, int, int); +#else +static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id) +{ + return -EOPNOTSUPP; +} +#endif + /* * Debugging key validation */ @@ -350,15 +378,4 @@ static inline void key_check(const struct key *key) #define key_check(key) do {} while(0) #endif - -/* - * Helper function to clear and free a kvmalloc'ed memory object. - */ -static inline void __kvzfree(const void *addr, size_t len) -{ - if (addr) { - memset((void *)addr, 0, len); - kvfree(addr); - } -} #endif /* _INTERNAL_H */ diff --git a/security/keys/key.c b/security/keys/key.c index e959b3c96b48..e282c6179b21 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -444,6 +444,7 @@ static int __key_instantiate_and_link(struct key *key, /* 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; @@ -453,7 +454,7 @@ static int __key_instantiate_and_link(struct key *key, if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) set_bit(KEY_FLAG_KEEP, &key->flags); - __key_link(key, _edit); + __key_link(keyring, key, _edit); } /* disable the authorisation key */ @@ -601,6 +602,7 @@ int key_reject_and_link(struct key *key, /* mark the key as being negatively instantiated */ atomic_inc(&key->user->nikeys); mark_key_instantiated(key, -error); + notify_key(key, NOTIFY_KEY_INSTANTIATED, -error); key->expiry = ktime_get_real_seconds() + timeout; key_schedule_gc(key->expiry + key_gc_delay); @@ -611,7 +613,7 @@ int key_reject_and_link(struct key *key, /* and link it into the destination keyring */ if (keyring && link_ret == 0) - __key_link(key, &edit); + __key_link(keyring, key, &edit); /* disable the authorisation key */ if (authkey) @@ -764,9 +766,11 @@ static inline key_ref_t __key_update(key_ref_t key_ref, down_write(&key->sem); ret = key->type->update(key, prep); - if (ret == 0) + if (ret == 0) { /* Updating a negative key positively instantiates it */ mark_key_instantiated(key, 0); + notify_key(key, NOTIFY_KEY_UPDATED, 0); + } up_write(&key->sem); @@ -1023,9 +1027,11 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen) down_write(&key->sem); ret = key->type->update(key, &prep); - if (ret == 0) + if (ret == 0) { /* Updating a negative key positively instantiates it */ mark_key_instantiated(key, 0); + notify_key(key, NOTIFY_KEY_UPDATED, 0); + } up_write(&key->sem); @@ -1057,15 +1063,17 @@ void key_revoke(struct key *key) * instantiated */ down_write_nested(&key->sem, 1); - if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && - key->type->revoke) - key->type->revoke(key); - - /* set the death time to no more than the expiry time */ - time = ktime_get_real_seconds(); - if (key->revoked_at == 0 || key->revoked_at > time) { - key->revoked_at = time; - key_schedule_gc(key->revoked_at + key_gc_delay); + if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) { + notify_key(key, NOTIFY_KEY_REVOKED, 0); + if (key->type->revoke) + key->type->revoke(key); + + /* set the death time to no more than the expiry time */ + time = ktime_get_real_seconds(); + if (key->revoked_at == 0 || key->revoked_at > time) { + key->revoked_at = time; + key_schedule_gc(key->revoked_at + key_gc_delay); + } } up_write(&key->sem); @@ -1087,8 +1095,10 @@ void key_invalidate(struct key *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)) + if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + notify_key(key, NOTIFY_KEY_INVALIDATED, 0); key_schedule_gc_links(); + } up_write(&key->sem); } } diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 5e01192e222a..9febd37a168f 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -37,7 +37,9 @@ static const unsigned char keyrings_capabilities[2] = { KEYCTL_CAPS0_MOVE ), [1] = (KEYCTL_CAPS1_NS_KEYRING_NAME | - KEYCTL_CAPS1_NS_KEY_TAG), + KEYCTL_CAPS1_NS_KEY_TAG | + (IS_ENABLED(CONFIG_KEY_NOTIFICATIONS) ? KEYCTL_CAPS1_NOTIFICATIONS : 0) + ), }; static int key_get_type_from_user(char *type, @@ -142,10 +144,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type, key_ref_put(keyring_ref); error3: - if (payload) { - memzero_explicit(payload, plen); - kvfree(payload); - } + kvfree_sensitive(payload, plen); error2: kfree(description); error: @@ -360,7 +359,7 @@ long keyctl_update_key(key_serial_t id, key_ref_put(key_ref); error2: - __kvzfree(payload, plen); + kvfree_sensitive(payload, plen); error: return ret; } @@ -432,7 +431,7 @@ long keyctl_invalidate_key(key_serial_t id) /* Root is permitted to invalidate certain special keys */ if (capable(CAP_SYS_ADMIN)) { - key_ref = lookup_user_key(id, 0, 0); + key_ref = lookup_user_key(id, 0, KEY_SYSADMIN_OVERRIDE); if (IS_ERR(key_ref)) goto error; if (test_bit(KEY_FLAG_ROOT_CAN_INVAL, @@ -477,7 +476,8 @@ long keyctl_keyring_clear(key_serial_t ringid) /* Root is permitted to invalidate certain special keyrings */ if (capable(CAP_SYS_ADMIN)) { - keyring_ref = lookup_user_key(ringid, 0, 0); + keyring_ref = lookup_user_key(ringid, 0, + KEY_SYSADMIN_OVERRIDE); if (IS_ERR(keyring_ref)) goto error; if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR, @@ -561,7 +561,7 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) goto error; } - key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0); + key_ref = lookup_user_key(id, KEY_LOOKUP_PARTIAL, KEY_NEED_UNLINK); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -661,7 +661,7 @@ long keyctl_describe_key(key_serial_t keyid, key_put(instkey); key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, - 0); + KEY_AUTHTOKEN_OVERRIDE); if (!IS_ERR(key_ref)) goto okay; } @@ -831,7 +831,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) size_t key_data_len; /* find the key first */ - key_ref = lookup_user_key(keyid, 0, 0); + key_ref = lookup_user_key(keyid, 0, KEY_DEFER_PERM_CHECK); if (IS_ERR(key_ref)) { ret = -ENOKEY; goto out; @@ -878,7 +878,7 @@ can_read_key: * * Allocating a temporary buffer to hold the keys before * transferring them to user buffer to avoid potential - * deadlock involving page fault and mmap_sem. + * deadlock involving page fault and mmap_lock. * * key_data_len = (buflen <= PAGE_SIZE) * ? buflen : actual length of key data @@ -914,7 +914,7 @@ can_read_key: */ if (ret > key_data_len) { if (unlikely(key_data)) - __kvzfree(key_data, key_data_len); + kvfree_sensitive(key_data, key_data_len); key_data_len = ret; continue; /* Allocate buffer */ } @@ -923,7 +923,7 @@ can_read_key: ret = -EFAULT; break; } - __kvzfree(key_data, key_data_len); + kvfree_sensitive(key_data, key_data_len); key_put_out: key_put(key); @@ -1039,6 +1039,7 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) if (group != (gid_t) -1) key->gid = gid; + notify_key(key, NOTIFY_KEY_SETATTR, 0); ret = 0; error_put: @@ -1089,6 +1090,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) /* if we're not the sysadmin, we can only change a key that we own */ if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { key->perm = perm; + notify_key(key, NOTIFY_KEY_SETATTR, 0); ret = 0; } @@ -1225,10 +1227,7 @@ long keyctl_instantiate_key_common(key_serial_t id, keyctl_change_reqkey_auth(NULL); error2: - if (payload) { - memzero_explicit(payload, plen); - kvfree(payload); - } + kvfree_sensitive(payload, plen); error: return ret; } @@ -1467,7 +1466,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout) key_put(instkey); key_ref = lookup_user_key(id, KEY_LOOKUP_PARTIAL, - 0); + KEY_AUTHTOKEN_OVERRIDE); if (!IS_ERR(key_ref)) goto okay; } @@ -1480,10 +1479,12 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout) okay: key = key_ref_to_ptr(key_ref); ret = 0; - if (test_bit(KEY_FLAG_KEEP, &key->flags)) + if (test_bit(KEY_FLAG_KEEP, &key->flags)) { ret = -EPERM; - else + } else { key_set_timeout(key, timeout); + notify_key(key, NOTIFY_KEY_SETATTR, 0); + } key_put(key); error: @@ -1573,7 +1574,8 @@ long keyctl_get_security(key_serial_t keyid, return PTR_ERR(instkey); key_put(instkey); - key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0); + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, + KEY_AUTHTOKEN_OVERRIDE); if (IS_ERR(key_ref)) return PTR_ERR(key_ref); } @@ -1757,6 +1759,90 @@ error: return ret; } +#ifdef CONFIG_KEY_NOTIFICATIONS +/* + * Watch for changes to a key. + * + * The caller must have View permission to watch a key or keyring. + */ +long keyctl_watch_key(key_serial_t id, int watch_queue_fd, int watch_id) +{ + struct watch_queue *wqueue; + struct watch_list *wlist = NULL; + struct watch *watch = NULL; + struct key *key; + key_ref_t key_ref; + long ret; + + if (watch_id < -1 || watch_id > 0xff) + return -EINVAL; + + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_VIEW); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + key = key_ref_to_ptr(key_ref); + + wqueue = get_watch_queue(watch_queue_fd); + if (IS_ERR(wqueue)) { + ret = PTR_ERR(wqueue); + goto err_key; + } + + if (watch_id >= 0) { + ret = -ENOMEM; + if (!key->watchers) { + wlist = kzalloc(sizeof(*wlist), GFP_KERNEL); + if (!wlist) + goto err_wqueue; + init_watch_list(wlist, NULL); + } + + watch = kzalloc(sizeof(*watch), GFP_KERNEL); + if (!watch) + goto err_wlist; + + init_watch(watch, wqueue); + watch->id = key->serial; + watch->info_id = (u32)watch_id << WATCH_INFO_ID__SHIFT; + + ret = security_watch_key(key); + if (ret < 0) + goto err_watch; + + down_write(&key->sem); + if (!key->watchers) { + key->watchers = wlist; + wlist = NULL; + } + + ret = add_watch_to_object(watch, key->watchers); + up_write(&key->sem); + + if (ret == 0) + watch = NULL; + } else { + ret = -EBADSLT; + if (key->watchers) { + down_write(&key->sem); + ret = remove_watch_from_object(key->watchers, + wqueue, key_serial(key), + false); + up_write(&key->sem); + } + } + +err_watch: + kfree(watch); +err_wlist: + kfree(wlist); +err_wqueue: + put_watch_queue(wqueue); +err_key: + key_put(key); + return ret; +} +#endif /* CONFIG_KEY_NOTIFICATIONS */ + /* * Get keyrings subsystem capabilities. */ @@ -1926,6 +2012,9 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, case KEYCTL_CAPABILITIES: return keyctl_capabilities((unsigned char __user *)arg2, (size_t)arg3); + case KEYCTL_WATCH_KEY: + return keyctl_watch_key((key_serial_t)arg2, (int)arg3, (int)arg4); + default: return -EOPNOTSUPP; } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 5ca620d31cd3..14abfe765b7e 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1056,12 +1056,14 @@ int keyring_restrict(key_ref_t keyring_ref, const char *type, down_write(&keyring->sem); down_write(&keyring_serialise_restrict_sem); - if (keyring->restrict_link) + if (keyring->restrict_link) { ret = -EEXIST; - else if (keyring_detect_restriction_cycle(keyring, restrict_link)) + } else if (keyring_detect_restriction_cycle(keyring, restrict_link)) { ret = -EDEADLK; - else + } else { keyring->restrict_link = restrict_link; + notify_key(keyring, NOTIFY_KEY_SETATTR, 0); + } up_write(&keyring_serialise_restrict_sem); up_write(&keyring->sem); @@ -1362,12 +1364,14 @@ int __key_link_check_live_key(struct key *keyring, struct key *key) * holds at most one link to any given key of a particular type+description * combination. */ -void __key_link(struct key *key, struct assoc_array_edit **_edit) +void __key_link(struct key *keyring, struct key *key, + struct assoc_array_edit **_edit) { __key_get(key); assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key)); assoc_array_apply_edit(*_edit); *_edit = NULL; + notify_key(keyring, NOTIFY_KEY_LINKED, key_serial(key)); } /* @@ -1451,7 +1455,7 @@ int key_link(struct key *keyring, struct key *key) if (ret == 0) ret = __key_link_check_live_key(keyring, key); if (ret == 0) - __key_link(key, &edit); + __key_link(keyring, key, &edit); error_end: __key_link_end(keyring, &key->index_key, edit); @@ -1483,7 +1487,7 @@ static int __key_unlink_begin(struct key *keyring, struct key *key, struct assoc_array_edit *edit; BUG_ON(*_edit != NULL); - + edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, &key->index_key); if (IS_ERR(edit)) @@ -1503,6 +1507,7 @@ static void __key_unlink(struct key *keyring, struct key *key, struct assoc_array_edit **_edit) { assoc_array_apply_edit(*_edit); + notify_key(keyring, NOTIFY_KEY_UNLINKED, key_serial(key)); *_edit = NULL; key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); } @@ -1621,7 +1626,7 @@ int key_move(struct key *key, goto error; __key_unlink(from_keyring, key, &from_edit); - __key_link(key, &to_edit); + __key_link(to_keyring, key, &to_edit); error: __key_link_end(to_keyring, &key->index_key, to_edit); __key_unlink_end(from_keyring, key, from_edit); @@ -1655,6 +1660,7 @@ int keyring_clear(struct key *keyring) } else { if (edit) assoc_array_apply_edit(edit); + notify_key(keyring, NOTIFY_KEY_CLEARED, 0); key_payload_reserve(keyring, 0); ret = 0; } diff --git a/security/keys/permission.c b/security/keys/permission.c index 085f907b64ac..4a61f804e80f 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -13,7 +13,7 @@ * key_task_permission - Check a key can be used * @key_ref: The key to check. * @cred: The credentials to use. - * @perm: The permissions to check for. + * @need_perm: The permission required. * * Check to see whether permission is granted to use a key in the desired way, * but permit the security modules to override. @@ -24,12 +24,30 @@ * permissions bits or the LSM check. */ int key_task_permission(const key_ref_t key_ref, const struct cred *cred, - unsigned perm) + enum key_need_perm need_perm) { struct key *key; - key_perm_t kperm; + key_perm_t kperm, mask; int ret; + switch (need_perm) { + default: + WARN_ON(1); + return -EACCES; + case KEY_NEED_UNLINK: + case KEY_SYSADMIN_OVERRIDE: + case KEY_AUTHTOKEN_OVERRIDE: + case KEY_DEFER_PERM_CHECK: + goto lsm; + + case KEY_NEED_VIEW: mask = KEY_OTH_VIEW; break; + case KEY_NEED_READ: mask = KEY_OTH_READ; break; + case KEY_NEED_WRITE: mask = KEY_OTH_WRITE; break; + case KEY_NEED_SEARCH: mask = KEY_OTH_SEARCH; break; + case KEY_NEED_LINK: mask = KEY_OTH_LINK; break; + case KEY_NEED_SETATTR: mask = KEY_OTH_SETATTR; break; + } + key = key_ref_to_ptr(key_ref); /* use the second 8-bits of permissions for keys the caller owns */ @@ -64,13 +82,12 @@ use_these_perms: if (is_key_possessed(key_ref)) kperm |= key->perm >> 24; - kperm = kperm & perm & KEY_NEED_ALL; - - if (kperm != perm) + if ((kperm & mask) != mask) return -EACCES; /* let LSM be the final arbiter */ - return security_key_permission(key_ref, cred, perm); +lsm: + return security_key_permission(key_ref, cred, need_perm); } EXPORT_SYMBOL(key_task_permission); diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 09541de31f2f..7e0232db1707 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -609,7 +609,7 @@ bool lookup_user_key_possessed(const struct key *key, * returned key reference. */ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, - key_perm_t perm) + enum key_need_perm need_perm) { struct keyring_search_context ctx = { .match_data.cmp = lookup_user_key_possessed, @@ -773,35 +773,33 @@ try_again: /* unlink does not use the nominated key in any way, so can skip all * the permission checks as it is only concerned with the keyring */ - if (lflags & KEY_LOOKUP_FOR_UNLINK) { - ret = 0; - goto error; - } - - if (!(lflags & KEY_LOOKUP_PARTIAL)) { - ret = wait_for_key_construction(key, true); - switch (ret) { - case -ERESTARTSYS: - goto invalid_key; - default: - if (perm) + if (need_perm != KEY_NEED_UNLINK) { + if (!(lflags & KEY_LOOKUP_PARTIAL)) { + ret = wait_for_key_construction(key, true); + switch (ret) { + case -ERESTARTSYS: + goto invalid_key; + default: + if (need_perm != KEY_AUTHTOKEN_OVERRIDE && + need_perm != KEY_DEFER_PERM_CHECK) + goto invalid_key; + case 0: + break; + } + } else if (need_perm != KEY_DEFER_PERM_CHECK) { + ret = key_validate(key); + if (ret < 0) goto invalid_key; - case 0: - break; } - } else if (perm) { - ret = key_validate(key); - if (ret < 0) + + ret = -EIO; + if (!(lflags & KEY_LOOKUP_PARTIAL) && + key_read_state(key) == KEY_IS_UNINSTANTIATED) goto invalid_key; } - ret = -EIO; - if (!(lflags & KEY_LOOKUP_PARTIAL) && - key_read_state(key) == KEY_IS_UNINSTANTIATED) - goto invalid_key; - /* check the permissions */ - ret = key_task_permission(key_ref, ctx.cred, perm); + ret = key_task_permission(key_ref, ctx.cred, need_perm); if (ret < 0) goto invalid_key; diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 957b9e3e1492..e1b9f1a80676 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -418,7 +418,7 @@ static int construct_alloc_key(struct keyring_search_context *ctx, goto key_already_present; if (dest_keyring) - __key_link(key, &edit); + __key_link(dest_keyring, key, &edit); mutex_unlock(&key_construction_mutex); if (dest_keyring) @@ -437,7 +437,7 @@ key_already_present: if (dest_keyring) { ret = __key_link_check_live_key(dest_keyring, key); if (ret == 0) - __key_link(key, &edit); + __key_link(dest_keyring, key, &edit); __key_link_end(dest_keyring, &ctx->index_key, edit); if (ret < 0) goto link_check_failed; |