diff options
Diffstat (limited to 'ANDROID_3.4.5/security/keys/keyctl.c')
| -rw-r--r-- | ANDROID_3.4.5/security/keys/keyctl.c | 1628 |
1 files changed, 0 insertions, 1628 deletions
diff --git a/ANDROID_3.4.5/security/keys/keyctl.c b/ANDROID_3.4.5/security/keys/keyctl.c deleted file mode 100644 index fb767c6c..00000000 --- a/ANDROID_3.4.5/security/keys/keyctl.c +++ /dev/null @@ -1,1628 +0,0 @@ -/* Userspace key control operations - * - * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/syscalls.h> -#include <linux/key.h> -#include <linux/keyctl.h> -#include <linux/fs.h> -#include <linux/capability.h> -#include <linux/string.h> -#include <linux/err.h> -#include <linux/vmalloc.h> -#include <linux/security.h> -#include <asm/uaccess.h> -#include "internal.h" - -static int key_get_type_from_user(char *type, - const char __user *_type, - unsigned len) -{ - int ret; - - ret = strncpy_from_user(type, _type, len); - if (ret < 0) - return ret; - if (ret == 0 || ret >= len) - return -EINVAL; - if (type[0] == '.') - return -EPERM; - type[len - 1] = '\0'; - return 0; -} - -/* - * Extract the description of a new key from userspace and either add it as a - * new key to the specified keyring or update a matching key in that keyring. - * - * The keyring must be writable so that we can attach the key to it. - * - * If successful, the new key's serial number is returned, otherwise an error - * code is returned. - */ -SYSCALL_DEFINE5(add_key, const char __user *, _type, - const char __user *, _description, - const void __user *, _payload, - size_t, plen, - key_serial_t, ringid) -{ - key_ref_t keyring_ref, key_ref; - char type[32], *description; - void *payload; - long ret; - bool vm; - - ret = -EINVAL; - if (plen > 1024 * 1024 - 1) - goto error; - - /* draw all the data into kernel space */ - ret = key_get_type_from_user(type, _type, sizeof(type)); - if (ret < 0) - goto error; - - description = strndup_user(_description, PAGE_SIZE); - if (IS_ERR(description)) { - ret = PTR_ERR(description); - goto error; - } - - /* pull the payload in if one was supplied */ - payload = NULL; - - vm = false; - if (_payload) { - ret = -ENOMEM; - payload = kmalloc(plen, GFP_KERNEL); - if (!payload) { - if (plen <= PAGE_SIZE) - goto error2; - vm = true; - payload = vmalloc(plen); - if (!payload) - goto error2; - } - - ret = -EFAULT; - if (copy_from_user(payload, _payload, plen) != 0) - goto error3; - } - - /* find the target keyring (which must be writable) */ - keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error3; - } - - /* create or update the requested key and add it to the target - * keyring */ - key_ref = key_create_or_update(keyring_ref, type, description, - payload, plen, KEY_PERM_UNDEF, - KEY_ALLOC_IN_QUOTA); - if (!IS_ERR(key_ref)) { - ret = key_ref_to_ptr(key_ref)->serial; - key_ref_put(key_ref); - } - else { - ret = PTR_ERR(key_ref); - } - - key_ref_put(keyring_ref); - error3: - if (!vm) - kfree(payload); - else - vfree(payload); - error2: - kfree(description); - error: - return ret; -} - -/* - * Search the process keyrings and keyring trees linked from those for a - * matching key. Keyrings must have appropriate Search permission to be - * searched. - * - * If a key is found, it will be attached to the destination keyring if there's - * one specified and the serial number of the key will be returned. - * - * If no key is found, /sbin/request-key will be invoked if _callout_info is - * non-NULL in an attempt to create a key. The _callout_info string will be - * passed to /sbin/request-key to aid with completing the request. If the - * _callout_info string is "" then it will be changed to "-". - */ -SYSCALL_DEFINE4(request_key, const char __user *, _type, - const char __user *, _description, - const char __user *, _callout_info, - key_serial_t, destringid) -{ - struct key_type *ktype; - struct key *key; - key_ref_t dest_ref; - size_t callout_len; - char type[32], *description, *callout_info; - long ret; - - /* pull the type into kernel space */ - ret = key_get_type_from_user(type, _type, sizeof(type)); - if (ret < 0) - goto error; - - /* pull the description into kernel space */ - description = strndup_user(_description, PAGE_SIZE); - if (IS_ERR(description)) { - ret = PTR_ERR(description); - goto error; - } - - /* pull the callout info into kernel space */ - callout_info = NULL; - callout_len = 0; - if (_callout_info) { - callout_info = strndup_user(_callout_info, PAGE_SIZE); - if (IS_ERR(callout_info)) { - ret = PTR_ERR(callout_info); - goto error2; - } - callout_len = strlen(callout_info); - } - - /* get the destination keyring if specified */ - dest_ref = NULL; - if (destringid) { - dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, - KEY_WRITE); - if (IS_ERR(dest_ref)) { - ret = PTR_ERR(dest_ref); - goto error3; - } - } - - /* find the key type */ - ktype = key_type_lookup(type); - if (IS_ERR(ktype)) { - ret = PTR_ERR(ktype); - goto error4; - } - - /* do the search */ - key = request_key_and_link(ktype, description, callout_info, - callout_len, NULL, key_ref_to_ptr(dest_ref), - KEY_ALLOC_IN_QUOTA); - if (IS_ERR(key)) { - ret = PTR_ERR(key); - goto error5; - } - - /* wait for the key to finish being constructed */ - ret = wait_for_key_construction(key, 1); - if (ret < 0) - goto error6; - - ret = key->serial; - -error6: - key_put(key); -error5: - key_type_put(ktype); -error4: - key_ref_put(dest_ref); -error3: - kfree(callout_info); -error2: - kfree(description); -error: - return ret; -} - -/* - * Get the ID of the specified process keyring. - * - * The requested keyring must have search permission to be found. - * - * If successful, the ID of the requested keyring will be returned. - */ -long keyctl_get_keyring_ID(key_serial_t id, int create) -{ - key_ref_t key_ref; - unsigned long lflags; - long ret; - - lflags = create ? KEY_LOOKUP_CREATE : 0; - key_ref = lookup_user_key(id, lflags, KEY_SEARCH); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error; - } - - ret = key_ref_to_ptr(key_ref)->serial; - key_ref_put(key_ref); -error: - return ret; -} - -/* - * Join a (named) session keyring. - * - * Create and join an anonymous session keyring or join a named session - * keyring, creating it if necessary. A named session keyring must have Search - * permission for it to be joined. Session keyrings without this permit will - * be skipped over. - * - * If successful, the ID of the joined session keyring will be returned. - */ -long keyctl_join_session_keyring(const char __user *_name) -{ - char *name; - long ret; - - /* fetch the name from userspace */ - name = NULL; - if (_name) { - name = strndup_user(_name, PAGE_SIZE); - if (IS_ERR(name)) { - ret = PTR_ERR(name); - goto error; - } - } - - /* join the session */ - ret = join_session_keyring(name); - kfree(name); - -error: - return ret; -} - -/* - * Update a key's data payload from the given data. - * - * The key must grant the caller Write permission and the key type must support - * updating for this to work. A negative key can be positively instantiated - * with this call. - * - * If successful, 0 will be returned. If the key type does not support - * updating, then -EOPNOTSUPP will be returned. - */ -long keyctl_update_key(key_serial_t id, - const void __user *_payload, - size_t plen) -{ - key_ref_t key_ref; - void *payload; - long ret; - - ret = -EINVAL; - if (plen > PAGE_SIZE) - goto error; - - /* pull the payload in if one was supplied */ - payload = NULL; - if (_payload) { - ret = -ENOMEM; - payload = kmalloc(plen, GFP_KERNEL); - if (!payload) - goto error; - - ret = -EFAULT; - if (copy_from_user(payload, _payload, plen) != 0) - goto error2; - } - - /* find the target key (which must be writable) */ - key_ref = lookup_user_key(id, 0, KEY_WRITE); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error2; - } - - /* update the key */ - ret = key_update(key_ref, payload, plen); - - key_ref_put(key_ref); -error2: - kfree(payload); -error: - return ret; -} - -/* - * Revoke a key. - * - * The key must be grant the caller Write or Setattr permission for this to - * work. The key type should give up its quota claim when revoked. The key - * and any links to the key will be automatically garbage collected after a - * certain amount of time (/proc/sys/kernel/keys/gc_delay). - * - * If successful, 0 is returned. - */ -long keyctl_revoke_key(key_serial_t id) -{ - key_ref_t key_ref; - long ret; - - key_ref = lookup_user_key(id, 0, KEY_WRITE); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - if (ret != -EACCES) - goto error; - key_ref = lookup_user_key(id, 0, KEY_SETATTR); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error; - } - } - - key_revoke(key_ref_to_ptr(key_ref)); - ret = 0; - - key_ref_put(key_ref); -error: - return ret; -} - -/* - * Clear the specified keyring, creating an empty process keyring if one of the - * special keyring IDs is used. - * - * The keyring must grant the caller Write permission for this to work. If - * successful, 0 will be returned. - */ -long keyctl_keyring_clear(key_serial_t ringid) -{ - key_ref_t keyring_ref; - long ret; - - keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - - /* Root is permitted to invalidate certain special keyrings */ - if (capable(CAP_SYS_ADMIN)) { - keyring_ref = lookup_user_key(ringid, 0, 0); - if (IS_ERR(keyring_ref)) - goto error; - if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR, - &key_ref_to_ptr(keyring_ref)->flags)) - goto clear; - goto error_put; - } - - goto error; - } - -clear: - ret = keyring_clear(key_ref_to_ptr(keyring_ref)); -error_put: - key_ref_put(keyring_ref); -error: - return ret; -} - -/* - * Create a link from a keyring to a key if there's no matching key in the - * keyring, otherwise replace the link to the matching key with a link to the - * new key. - * - * The key must grant the caller Link permission and the the keyring must grant - * the caller Write permission. Furthermore, if an additional link is created, - * the keyring's quota will be extended. - * - * If successful, 0 will be returned. - */ -long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) -{ - key_ref_t keyring_ref, key_ref; - long ret; - - keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error; - } - - key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error2; - } - - ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); - - key_ref_put(key_ref); -error2: - key_ref_put(keyring_ref); -error: - return ret; -} - -/* - * Unlink a key from a keyring. - * - * The keyring must grant the caller Write permission for this to work; the key - * itself need not grant the caller anything. If the last link to a key is - * removed then that key will be scheduled for destruction. - * - * If successful, 0 will be returned. - */ -long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) -{ - key_ref_t keyring_ref, key_ref; - long ret; - - keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error; - } - - key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error2; - } - - ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); - - key_ref_put(key_ref); -error2: - key_ref_put(keyring_ref); -error: - return ret; -} - -/* - * Return a description of a key to userspace. - * - * The key must grant the caller View permission for this to work. - * - * If there's a buffer, we place up to buflen bytes of data into it formatted - * in the following way: - * - * type;uid;gid;perm;description<NUL> - * - * If successful, we return the amount of description available, irrespective - * of how much we may have copied into the buffer. - */ -long keyctl_describe_key(key_serial_t keyid, - char __user *buffer, - size_t buflen) -{ - struct key *key, *instkey; - key_ref_t key_ref; - char *tmpbuf; - long ret; - - key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW); - if (IS_ERR(key_ref)) { - /* viewing a key under construction is permitted if we have the - * authorisation token handy */ - if (PTR_ERR(key_ref) == -EACCES) { - instkey = key_get_instantiation_authkey(keyid); - if (!IS_ERR(instkey)) { - key_put(instkey); - key_ref = lookup_user_key(keyid, - KEY_LOOKUP_PARTIAL, - 0); - if (!IS_ERR(key_ref)) - goto okay; - } - } - - ret = PTR_ERR(key_ref); - goto error; - } - -okay: - /* calculate how much description we're going to return */ - ret = -ENOMEM; - tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!tmpbuf) - goto error2; - - key = key_ref_to_ptr(key_ref); - - ret = snprintf(tmpbuf, PAGE_SIZE - 1, - "%s;%d;%d;%08x;%s", - key->type->name, - key->uid, - key->gid, - key->perm, - key->description ?: ""); - - /* include a NUL char at the end of the data */ - if (ret > PAGE_SIZE - 1) - ret = PAGE_SIZE - 1; - tmpbuf[ret] = 0; - ret++; - - /* consider returning the data */ - if (buffer && buflen > 0) { - if (buflen > ret) - buflen = ret; - - if (copy_to_user(buffer, tmpbuf, buflen) != 0) - ret = -EFAULT; - } - - kfree(tmpbuf); -error2: - key_ref_put(key_ref); -error: - return ret; -} - -/* - * Search the specified keyring and any keyrings it links to for a matching - * key. Only keyrings that grant the caller Search permission will be searched - * (this includes the starting keyring). Only keys with Search permission can - * be found. - * - * If successful, the found key will be linked to the destination keyring if - * supplied and the key has Link permission, and the found key ID will be - * returned. - */ -long keyctl_keyring_search(key_serial_t ringid, - const char __user *_type, - const char __user *_description, - key_serial_t destringid) -{ - struct key_type *ktype; - key_ref_t keyring_ref, key_ref, dest_ref; - char type[32], *description; - long ret; - - /* pull the type and description into kernel space */ - ret = key_get_type_from_user(type, _type, sizeof(type)); - if (ret < 0) - goto error; - - description = strndup_user(_description, PAGE_SIZE); - if (IS_ERR(description)) { - ret = PTR_ERR(description); - goto error; - } - - /* get the keyring at which to begin the search */ - keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error2; - } - - /* get the destination keyring if specified */ - dest_ref = NULL; - if (destringid) { - dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, - KEY_WRITE); - if (IS_ERR(dest_ref)) { - ret = PTR_ERR(dest_ref); - goto error3; - } - } - - /* find the key type */ - ktype = key_type_lookup(type); - if (IS_ERR(ktype)) { - ret = PTR_ERR(ktype); - goto error4; - } - - /* do the search */ - key_ref = keyring_search(keyring_ref, ktype, description); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - - /* treat lack or presence of a negative key the same */ - if (ret == -EAGAIN) - ret = -ENOKEY; - goto error5; - } - - /* link the resulting key to the destination keyring if we can */ - if (dest_ref) { - ret = key_permission(key_ref, KEY_LINK); - if (ret < 0) - goto error6; - - ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); - if (ret < 0) - goto error6; - } - - ret = key_ref_to_ptr(key_ref)->serial; - -error6: - key_ref_put(key_ref); -error5: - key_type_put(ktype); -error4: - key_ref_put(dest_ref); -error3: - key_ref_put(keyring_ref); -error2: - kfree(description); -error: - return ret; -} - -/* - * Read a key's payload. - * - * The key must either grant the caller Read permission, or it must grant the - * caller Search permission when searched for from the process keyrings. - * - * If successful, we place up to buflen bytes of data into the buffer, if one - * is provided, and return the amount of data that is available in the key, - * irrespective of how much we copied into the buffer. - */ -long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) -{ - struct key *key; - key_ref_t key_ref; - long ret; - - /* find the key first */ - key_ref = lookup_user_key(keyid, 0, 0); - if (IS_ERR(key_ref)) { - ret = -ENOKEY; - goto error; - } - - key = key_ref_to_ptr(key_ref); - - /* see if we can read it directly */ - ret = key_permission(key_ref, KEY_READ); - if (ret == 0) - goto can_read_key; - if (ret != -EACCES) - goto error; - - /* we can't; see if it's searchable from this process's keyrings - * - we automatically take account of the fact that it may be - * dangling off an instantiation key - */ - if (!is_key_possessed(key_ref)) { - ret = -EACCES; - goto error2; - } - - /* the key is probably readable - now try to read it */ -can_read_key: - ret = key_validate(key); - if (ret == 0) { - ret = -EOPNOTSUPP; - if (key->type->read) { - /* read the data with the semaphore held (since we - * might sleep) */ - down_read(&key->sem); - ret = key->type->read(key, buffer, buflen); - up_read(&key->sem); - } - } - -error2: - key_put(key); -error: - return ret; -} - -/* - * Change the ownership of a key - * - * The key must grant the caller Setattr permission for this to work, though - * the key need not be fully instantiated yet. For the UID to be changed, or - * for the GID to be changed to a group the caller is not a member of, the - * caller must have sysadmin capability. If either uid or gid is -1 then that - * attribute is not changed. - * - * If the UID is to be changed, the new user must have sufficient quota to - * accept the key. The quota deduction will be removed from the old user to - * the new user should the attribute be changed. - * - * If successful, 0 will be returned. - */ -long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) -{ - struct key_user *newowner, *zapowner = NULL; - struct key *key; - key_ref_t key_ref; - long ret; - - ret = 0; - if (uid == (uid_t) -1 && gid == (gid_t) -1) - goto error; - - key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, - KEY_SETATTR); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error; - } - - key = key_ref_to_ptr(key_ref); - - /* make the changes with the locks held to prevent chown/chown races */ - ret = -EACCES; - down_write(&key->sem); - - if (!capable(CAP_SYS_ADMIN)) { - /* only the sysadmin can chown a key to some other UID */ - if (uid != (uid_t) -1 && key->uid != uid) - goto error_put; - - /* only the sysadmin can set the key's GID to a group other - * than one of those that the current process subscribes to */ - if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) - goto error_put; - } - - /* change the UID */ - if (uid != (uid_t) -1 && uid != key->uid) { - ret = -ENOMEM; - newowner = key_user_lookup(uid, current_user_ns()); - if (!newowner) - goto error_put; - - /* transfer the quota burden to the new user */ - if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - unsigned maxkeys = (uid == 0) ? - key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (uid == 0) ? - key_quota_root_maxbytes : key_quota_maxbytes; - - spin_lock(&newowner->lock); - if (newowner->qnkeys + 1 >= maxkeys || - newowner->qnbytes + key->quotalen >= maxbytes || - newowner->qnbytes + key->quotalen < - newowner->qnbytes) - goto quota_overrun; - - newowner->qnkeys++; - newowner->qnbytes += key->quotalen; - spin_unlock(&newowner->lock); - - spin_lock(&key->user->lock); - key->user->qnkeys--; - key->user->qnbytes -= key->quotalen; - spin_unlock(&key->user->lock); - } - - atomic_dec(&key->user->nkeys); - atomic_inc(&newowner->nkeys); - - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { - atomic_dec(&key->user->nikeys); - atomic_inc(&newowner->nikeys); - } - - zapowner = key->user; - key->user = newowner; - key->uid = uid; - } - - /* change the GID */ - if (gid != (gid_t) -1) - key->gid = gid; - - ret = 0; - -error_put: - up_write(&key->sem); - key_put(key); - if (zapowner) - key_user_put(zapowner); -error: - return ret; - -quota_overrun: - spin_unlock(&newowner->lock); - zapowner = newowner; - ret = -EDQUOT; - goto error_put; -} - -/* - * Change the permission mask on a key. - * - * The key must grant the caller Setattr permission for this to work, though - * the key need not be fully instantiated yet. If the caller does not have - * sysadmin capability, it may only change the permission on keys that it owns. - */ -long keyctl_setperm_key(key_serial_t id, key_perm_t perm) -{ - struct key *key; - key_ref_t key_ref; - long ret; - - ret = -EINVAL; - if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) - goto error; - - key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, - KEY_SETATTR); - if (IS_ERR(key_ref)) { - ret = PTR_ERR(key_ref); - goto error; - } - - key = key_ref_to_ptr(key_ref); - - /* make the changes with the locks held to prevent chown/chmod races */ - ret = -EACCES; - down_write(&key->sem); - - /* if we're not the sysadmin, we can only change a key that we own */ - if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) { - key->perm = perm; - ret = 0; - } - - up_write(&key->sem); - key_put(key); -error: - return ret; -} - -/* - * Get the destination keyring for instantiation and check that the caller has - * Write permission on it. - */ -static long get_instantiation_keyring(key_serial_t ringid, - struct request_key_auth *rka, - struct key **_dest_keyring) -{ - key_ref_t dkref; - - *_dest_keyring = NULL; - - /* just return a NULL pointer if we weren't asked to make a link */ - if (ringid == 0) - return 0; - - /* if a specific keyring is nominated by ID, then use that */ - if (ringid > 0) { - dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); - if (IS_ERR(dkref)) - return PTR_ERR(dkref); - *_dest_keyring = key_ref_to_ptr(dkref); - return 0; - } - - if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) - return -EINVAL; - - /* otherwise specify the destination keyring recorded in the - * authorisation key (any KEY_SPEC_*_KEYRING) */ - if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { - *_dest_keyring = key_get(rka->dest_keyring); - return 0; - } - - return -ENOKEY; -} - -/* - * Change the request_key authorisation key on the current process. - */ -static int keyctl_change_reqkey_auth(struct key *key) -{ - struct cred *new; - - new = prepare_creds(); - if (!new) - return -ENOMEM; - - key_put(new->request_key_auth); - new->request_key_auth = key_get(key); - - return commit_creds(new); -} - -/* - * Copy the iovec data from userspace - */ -static long copy_from_user_iovec(void *buffer, const struct iovec *iov, - unsigned ioc) -{ - for (; ioc > 0; ioc--) { - if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0) - return -EFAULT; - buffer += iov->iov_len; - iov++; - } - return 0; -} - -/* - * Instantiate a key with the specified payload and link the key into the - * destination keyring if one is given. - * - * The caller must have the appropriate instantiation permit set for this to - * work (see keyctl_assume_authority). No other permissions are required. - * - * If successful, 0 will be returned. - */ -long keyctl_instantiate_key_common(key_serial_t id, - const struct iovec *payload_iov, - unsigned ioc, - size_t plen, - key_serial_t ringid) -{ - const struct cred *cred = current_cred(); - struct request_key_auth *rka; - struct key *instkey, *dest_keyring; - void *payload; - long ret; - bool vm = false; - - kenter("%d,,%zu,%d", id, plen, ringid); - - ret = -EINVAL; - if (plen > 1024 * 1024 - 1) - goto error; - - /* the appropriate instantiation authorisation key must have been - * assumed before calling this */ - ret = -EPERM; - instkey = cred->request_key_auth; - if (!instkey) - goto error; - - rka = instkey->payload.data; - if (rka->target_key->serial != id) - goto error; - - /* pull the payload in if one was supplied */ - payload = NULL; - - if (payload_iov) { - ret = -ENOMEM; - payload = kmalloc(plen, GFP_KERNEL); - if (!payload) { - if (plen <= PAGE_SIZE) - goto error; - vm = true; - payload = vmalloc(plen); - if (!payload) - goto error; - } - - ret = copy_from_user_iovec(payload, payload_iov, ioc); - if (ret < 0) - goto error2; - } - - /* find the destination keyring amongst those belonging to the - * requesting task */ - ret = get_instantiation_keyring(ringid, rka, &dest_keyring); - if (ret < 0) - goto error2; - - /* instantiate the key and link it into a keyring */ - ret = key_instantiate_and_link(rka->target_key, payload, plen, - dest_keyring, instkey); - - key_put(dest_keyring); - - /* discard the assumed authority if it's just been disabled by - * instantiation of the key */ - if (ret == 0) - keyctl_change_reqkey_auth(NULL); - -error2: - if (!vm) - kfree(payload); - else - vfree(payload); -error: - return ret; -} - -/* - * Instantiate a key with the specified payload and link the key into the - * destination keyring if one is given. - * - * The caller must have the appropriate instantiation permit set for this to - * work (see keyctl_assume_authority). No other permissions are required. - * - * If successful, 0 will be returned. - */ -long keyctl_instantiate_key(key_serial_t id, - const void __user *_payload, - size_t plen, - key_serial_t ringid) -{ - if (_payload && plen) { - struct iovec iov[1] = { - [0].iov_base = (void __user *)_payload, - [0].iov_len = plen - }; - - return keyctl_instantiate_key_common(id, iov, 1, plen, ringid); - } - - return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); -} - -/* - * Instantiate a key with the specified multipart payload and link the key into - * the destination keyring if one is given. - * - * The caller must have the appropriate instantiation permit set for this to - * work (see keyctl_assume_authority). No other permissions are required. - * - * If successful, 0 will be returned. - */ -long keyctl_instantiate_key_iov(key_serial_t id, - const struct iovec __user *_payload_iov, - unsigned ioc, - key_serial_t ringid) -{ - struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; - long ret; - - if (_payload_iov == 0 || ioc == 0) - goto no_payload; - - ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc, - ARRAY_SIZE(iovstack), iovstack, &iov, 1); - if (ret < 0) - return ret; - if (ret == 0) - goto no_payload_free; - - ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid); - - if (iov != iovstack) - kfree(iov); - return ret; - -no_payload_free: - if (iov != iovstack) - kfree(iov); -no_payload: - return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); -} - -/* - * Negatively instantiate the key with the given timeout (in seconds) and link - * the key into the destination keyring if one is given. - * - * The caller must have the appropriate instantiation permit set for this to - * work (see keyctl_assume_authority). No other permissions are required. - * - * The key and any links to the key will be automatically garbage collected - * after the timeout expires. - * - * Negative keys are used to rate limit repeated request_key() calls by causing - * them to return -ENOKEY until the negative key expires. - * - * If successful, 0 will be returned. - */ -long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) -{ - return keyctl_reject_key(id, timeout, ENOKEY, ringid); -} - -/* - * Negatively instantiate the key with the given timeout (in seconds) and error - * code and link the key into the destination keyring if one is given. - * - * The caller must have the appropriate instantiation permit set for this to - * work (see keyctl_assume_authority). No other permissions are required. - * - * The key and any links to the key will be automatically garbage collected - * after the timeout expires. - * - * Negative keys are used to rate limit repeated request_key() calls by causing - * them to return the specified error code until the negative key expires. - * - * If successful, 0 will be returned. - */ -long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error, - key_serial_t ringid) -{ - const struct cred *cred = current_cred(); - struct request_key_auth *rka; - struct key *instkey, *dest_keyring; - long ret; - - kenter("%d,%u,%u,%d", id, timeout, error, ringid); - - /* must be a valid error code and mustn't be a kernel special */ - if (error <= 0 || - error >= MAX_ERRNO || - error == ERESTARTSYS || - error == ERESTARTNOINTR || - error == ERESTARTNOHAND || - error == ERESTART_RESTARTBLOCK) - return -EINVAL; - - /* the appropriate instantiation authorisation key must have been - * assumed before calling this */ - ret = -EPERM; - instkey = cred->request_key_auth; - if (!instkey) - goto error; - - rka = instkey->payload.data; - if (rka->target_key->serial != id) - goto error; - - /* find the destination keyring if present (which must also be - * writable) */ - ret = get_instantiation_keyring(ringid, rka, &dest_keyring); - if (ret < 0) - goto error; - - /* instantiate the key and link it into a keyring */ - ret = key_reject_and_link(rka->target_key, timeout, error, - dest_keyring, instkey); - - key_put(dest_keyring); - - /* discard the assumed authority if it's just been disabled by - * instantiation of the key */ - if (ret == 0) - keyctl_change_reqkey_auth(NULL); - -error: - return ret; -} - -/* - * Read or set the default keyring in which request_key() will cache keys and - * return the old setting. - * - * If a process keyring is specified then this will be created if it doesn't - * yet exist. The old setting will be returned if successful. - */ -long keyctl_set_reqkey_keyring(int reqkey_defl) -{ - struct cred *new; - int ret, old_setting; - - old_setting = current_cred_xxx(jit_keyring); - - if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) - return old_setting; - - new = prepare_creds(); - if (!new) - return -ENOMEM; - - switch (reqkey_defl) { - case KEY_REQKEY_DEFL_THREAD_KEYRING: - ret = install_thread_keyring_to_cred(new); - if (ret < 0) - goto error; - goto set; - - case KEY_REQKEY_DEFL_PROCESS_KEYRING: - ret = install_process_keyring_to_cred(new); - if (ret < 0) { - if (ret != -EEXIST) - goto error; - ret = 0; - } - goto set; - - case KEY_REQKEY_DEFL_DEFAULT: - case KEY_REQKEY_DEFL_SESSION_KEYRING: - case KEY_REQKEY_DEFL_USER_KEYRING: - case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: - case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: - goto set; - - case KEY_REQKEY_DEFL_NO_CHANGE: - case KEY_REQKEY_DEFL_GROUP_KEYRING: - default: - ret = -EINVAL; - goto error; - } - -set: - new->jit_keyring = reqkey_defl; - commit_creds(new); - return old_setting; -error: - abort_creds(new); - return ret; -} - -/* - * Set or clear the timeout on a key. - * - * Either the key must grant the caller Setattr permission or else the caller - * must hold an instantiation authorisation token for the key. - * - * The timeout is either 0 to clear the timeout, or a number of seconds from - * the current time. The key and any links to the key will be automatically - * garbage collected after the timeout expires. - * - * If successful, 0 is returned. - */ -long keyctl_set_timeout(key_serial_t id, unsigned timeout) -{ - struct key *key, *instkey; - key_ref_t key_ref; - long ret; - - key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, - KEY_SETATTR); - if (IS_ERR(key_ref)) { - /* setting the timeout on a key under construction is permitted - * if we have the authorisation token handy */ - if (PTR_ERR(key_ref) == -EACCES) { - instkey = key_get_instantiation_authkey(id); - if (!IS_ERR(instkey)) { - key_put(instkey); - key_ref = lookup_user_key(id, - KEY_LOOKUP_PARTIAL, - 0); - if (!IS_ERR(key_ref)) - goto okay; - } - } - - ret = PTR_ERR(key_ref); - goto error; - } - -okay: - key = key_ref_to_ptr(key_ref); - key_set_timeout(key, timeout); - key_put(key); - - ret = 0; -error: - return ret; -} - -/* - * Assume (or clear) the authority to instantiate the specified key. - * - * This sets the authoritative token currently in force for key instantiation. - * This must be done for a key to be instantiated. It has the effect of making - * available all the keys from the caller of the request_key() that created a - * key to request_key() calls made by the caller of this function. - * - * The caller must have the instantiation key in their process keyrings with a - * Search permission grant available to the caller. - * - * If the ID given is 0, then the setting will be cleared and 0 returned. - * - * If the ID given has a matching an authorisation key, then that key will be - * set and its ID will be returned. The authorisation key can be read to get - * the callout information passed to request_key(). - */ -long keyctl_assume_authority(key_serial_t id) -{ - struct key *authkey; - long ret; - - /* special key IDs aren't permitted */ - ret = -EINVAL; - if (id < 0) - goto error; - - /* we divest ourselves of authority if given an ID of 0 */ - if (id == 0) { - ret = keyctl_change_reqkey_auth(NULL); - goto error; - } - - /* attempt to assume the authority temporarily granted to us whilst we - * instantiate the specified key - * - the authorisation key must be in the current task's keyrings - * somewhere - */ - authkey = key_get_instantiation_authkey(id); - if (IS_ERR(authkey)) { - ret = PTR_ERR(authkey); - goto error; - } - - ret = keyctl_change_reqkey_auth(authkey); - if (ret < 0) - goto error; - key_put(authkey); - - ret = authkey->serial; -error: - return ret; -} - -/* - * Get a key's the LSM security label. - * - * The key must grant the caller View permission for this to work. - * - * If there's a buffer, then up to buflen bytes of data will be placed into it. - * - * If successful, the amount of information available will be returned, - * irrespective of how much was copied (including the terminal NUL). - */ -long keyctl_get_security(key_serial_t keyid, - char __user *buffer, - size_t buflen) -{ - struct key *key, *instkey; - key_ref_t key_ref; - char *context; - long ret; - - key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW); - if (IS_ERR(key_ref)) { - if (PTR_ERR(key_ref) != -EACCES) - return PTR_ERR(key_ref); - - /* viewing a key under construction is also permitted if we - * have the authorisation token handy */ - instkey = key_get_instantiation_authkey(keyid); - if (IS_ERR(instkey)) - return PTR_ERR(instkey); - key_put(instkey); - - key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0); - if (IS_ERR(key_ref)) - return PTR_ERR(key_ref); - } - - key = key_ref_to_ptr(key_ref); - ret = security_key_getsecurity(key, &context); - if (ret == 0) { - /* if no information was returned, give userspace an empty - * string */ - ret = 1; - if (buffer && buflen > 0 && - copy_to_user(buffer, "", 1) != 0) - ret = -EFAULT; - } else if (ret > 0) { - /* return as much data as there's room for */ - if (buffer && buflen > 0) { - if (buflen > ret) - buflen = ret; - - if (copy_to_user(buffer, context, buflen) != 0) - ret = -EFAULT; - } - - kfree(context); - } - - key_ref_put(key_ref); - return ret; -} - -/* - * Attempt to install the calling process's session keyring on the process's - * parent process. - * - * The keyring must exist and must grant the caller LINK permission, and the - * parent process must be single-threaded and must have the same effective - * ownership as this process and mustn't be SUID/SGID. - * - * The keyring will be emplaced on the parent when it next resumes userspace. - * - * If successful, 0 will be returned. - */ -long keyctl_session_to_parent(void) -{ -#ifdef TIF_NOTIFY_RESUME - struct task_struct *me, *parent; - const struct cred *mycred, *pcred; - struct cred *cred, *oldcred; - key_ref_t keyring_r; - int ret; - - keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK); - if (IS_ERR(keyring_r)) - return PTR_ERR(keyring_r); - - /* our parent is going to need a new cred struct, a new tgcred struct - * and new security data, so we allocate them here to prevent ENOMEM in - * our parent */ - ret = -ENOMEM; - cred = cred_alloc_blank(); - if (!cred) - goto error_keyring; - - cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r); - keyring_r = NULL; - - me = current; - rcu_read_lock(); - write_lock_irq(&tasklist_lock); - - parent = me->real_parent; - ret = -EPERM; - - /* the parent mustn't be init and mustn't be a kernel thread */ - if (parent->pid <= 1 || !parent->mm) - goto not_permitted; - - /* the parent must be single threaded */ - if (!thread_group_empty(parent)) - goto not_permitted; - - /* the parent and the child must have different session keyrings or - * there's no point */ - mycred = current_cred(); - pcred = __task_cred(parent); - if (mycred == pcred || - mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) - goto already_same; - - /* the parent must have the same effective ownership and mustn't be - * SUID/SGID */ - if (pcred->uid != mycred->euid || - pcred->euid != mycred->euid || - pcred->suid != mycred->euid || - pcred->gid != mycred->egid || - pcred->egid != mycred->egid || - pcred->sgid != mycred->egid) - goto not_permitted; - - /* the keyrings must have the same UID */ - if ((pcred->tgcred->session_keyring && - pcred->tgcred->session_keyring->uid != mycred->euid) || - mycred->tgcred->session_keyring->uid != mycred->euid) - goto not_permitted; - - /* if there's an already pending keyring replacement, then we replace - * that */ - oldcred = parent->replacement_session_keyring; - - /* the replacement session keyring is applied just prior to userspace - * restarting */ - parent->replacement_session_keyring = cred; - cred = NULL; - set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME); - - write_unlock_irq(&tasklist_lock); - rcu_read_unlock(); - if (oldcred) - put_cred(oldcred); - return 0; - -already_same: - ret = 0; -not_permitted: - write_unlock_irq(&tasklist_lock); - rcu_read_unlock(); - put_cred(cred); - return ret; - -error_keyring: - key_ref_put(keyring_r); - return ret; - -#else /* !TIF_NOTIFY_RESUME */ - /* - * To be removed when TIF_NOTIFY_RESUME has been implemented on - * m68k/xtensa - */ -#warning TIF_NOTIFY_RESUME not implemented - return -EOPNOTSUPP; -#endif /* !TIF_NOTIFY_RESUME */ -} - -/* - * The key control system call - */ -SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, - unsigned long, arg4, unsigned long, arg5) -{ - switch (option) { - case KEYCTL_GET_KEYRING_ID: - return keyctl_get_keyring_ID((key_serial_t) arg2, - (int) arg3); - - case KEYCTL_JOIN_SESSION_KEYRING: - return keyctl_join_session_keyring((const char __user *) arg2); - - case KEYCTL_UPDATE: - return keyctl_update_key((key_serial_t) arg2, - (const void __user *) arg3, - (size_t) arg4); - - case KEYCTL_REVOKE: - return keyctl_revoke_key((key_serial_t) arg2); - - case KEYCTL_DESCRIBE: - return keyctl_describe_key((key_serial_t) arg2, - (char __user *) arg3, - (unsigned) arg4); - - case KEYCTL_CLEAR: - return keyctl_keyring_clear((key_serial_t) arg2); - - case KEYCTL_LINK: - return keyctl_keyring_link((key_serial_t) arg2, - (key_serial_t) arg3); - - case KEYCTL_UNLINK: - return keyctl_keyring_unlink((key_serial_t) arg2, - (key_serial_t) arg3); - - case KEYCTL_SEARCH: - return keyctl_keyring_search((key_serial_t) arg2, - (const char __user *) arg3, - (const char __user *) arg4, - (key_serial_t) arg5); - - case KEYCTL_READ: - return keyctl_read_key((key_serial_t) arg2, - (char __user *) arg3, - (size_t) arg4); - - case KEYCTL_CHOWN: - return keyctl_chown_key((key_serial_t) arg2, - (uid_t) arg3, - (gid_t) arg4); - - case KEYCTL_SETPERM: - return keyctl_setperm_key((key_serial_t) arg2, - (key_perm_t) arg3); - - case KEYCTL_INSTANTIATE: - return keyctl_instantiate_key((key_serial_t) arg2, - (const void __user *) arg3, - (size_t) arg4, - (key_serial_t) arg5); - - case KEYCTL_NEGATE: - return keyctl_negate_key((key_serial_t) arg2, - (unsigned) arg3, - (key_serial_t) arg4); - - case KEYCTL_SET_REQKEY_KEYRING: - return keyctl_set_reqkey_keyring(arg2); - - case KEYCTL_SET_TIMEOUT: - return keyctl_set_timeout((key_serial_t) arg2, - (unsigned) arg3); - - case KEYCTL_ASSUME_AUTHORITY: - return keyctl_assume_authority((key_serial_t) arg2); - - case KEYCTL_GET_SECURITY: - return keyctl_get_security((key_serial_t) arg2, - (char __user *) arg3, - (size_t) arg4); - - case KEYCTL_SESSION_TO_PARENT: - return keyctl_session_to_parent(); - - case KEYCTL_REJECT: - return keyctl_reject_key((key_serial_t) arg2, - (unsigned) arg3, - (unsigned) arg4, - (key_serial_t) arg5); - - case KEYCTL_INSTANTIATE_IOV: - return keyctl_instantiate_key_iov( - (key_serial_t) arg2, - (const struct iovec __user *) arg3, - (unsigned) arg4, - (key_serial_t) arg5); - - default: - return -EOPNOTSUPP; - } -} |