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![Gustavo A. R. Silva](/assets/img/avatar_default.png)
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
805 lines
21 KiB
C
805 lines
21 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Request a key from userspace
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*
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* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* See Documentation/security/keys/request-key.rst
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*/
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/kmod.h>
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#include <linux/err.h>
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#include <linux/keyctl.h>
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#include <linux/slab.h>
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#include <net/net_namespace.h>
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#include "internal.h"
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#include <keys/request_key_auth-type.h>
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#define key_negative_timeout 60 /* default timeout on a negative key's existence */
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static struct key *check_cached_key(struct keyring_search_context *ctx)
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{
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#ifdef CONFIG_KEYS_REQUEST_CACHE
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struct key *key = current->cached_requested_key;
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if (key &&
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ctx->match_data.cmp(key, &ctx->match_data) &&
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!(key->flags & ((1 << KEY_FLAG_INVALIDATED) |
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(1 << KEY_FLAG_REVOKED))))
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return key_get(key);
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#endif
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return NULL;
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}
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static void cache_requested_key(struct key *key)
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{
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#ifdef CONFIG_KEYS_REQUEST_CACHE
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struct task_struct *t = current;
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key_put(t->cached_requested_key);
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t->cached_requested_key = key_get(key);
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set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
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#endif
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}
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/**
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* complete_request_key - Complete the construction of a key.
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* @authkey: The authorisation key.
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* @error: The success or failute of the construction.
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*
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* Complete the attempt to construct a key. The key will be negated
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* if an error is indicated. The authorisation key will be revoked
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* unconditionally.
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*/
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void complete_request_key(struct key *authkey, int error)
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{
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struct request_key_auth *rka = get_request_key_auth(authkey);
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struct key *key = rka->target_key;
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kenter("%d{%d},%d", authkey->serial, key->serial, error);
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if (error < 0)
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key_negate_and_link(key, key_negative_timeout, NULL, authkey);
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else
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key_revoke(authkey);
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}
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EXPORT_SYMBOL(complete_request_key);
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/*
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* Initialise a usermode helper that is going to have a specific session
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* keyring.
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*
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* This is called in context of freshly forked kthread before kernel_execve(),
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* so we can simply install the desired session_keyring at this point.
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*/
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static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
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{
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struct key *keyring = info->data;
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return install_session_keyring_to_cred(cred, keyring);
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}
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/*
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* Clean up a usermode helper with session keyring.
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*/
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static void umh_keys_cleanup(struct subprocess_info *info)
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{
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struct key *keyring = info->data;
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key_put(keyring);
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}
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/*
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* Call a usermode helper with a specific session keyring.
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*/
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static int call_usermodehelper_keys(const char *path, char **argv, char **envp,
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struct key *session_keyring, int wait)
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{
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struct subprocess_info *info;
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info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL,
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umh_keys_init, umh_keys_cleanup,
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session_keyring);
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if (!info)
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return -ENOMEM;
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key_get(session_keyring);
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return call_usermodehelper_exec(info, wait);
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}
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/*
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* Request userspace finish the construction of a key
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* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
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*/
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static int call_sbin_request_key(struct key *authkey, void *aux)
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{
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static char const request_key[] = "/sbin/request-key";
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struct request_key_auth *rka = get_request_key_auth(authkey);
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const struct cred *cred = current_cred();
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key_serial_t prkey, sskey;
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struct key *key = rka->target_key, *keyring, *session, *user_session;
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char *argv[9], *envp[3], uid_str[12], gid_str[12];
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char key_str[12], keyring_str[3][12];
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char desc[20];
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int ret, i;
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kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op);
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ret = look_up_user_keyrings(NULL, &user_session);
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if (ret < 0)
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goto error_us;
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/* allocate a new session keyring */
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sprintf(desc, "_req.%u", key->serial);
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cred = get_current_cred();
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keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
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KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
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KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
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put_cred(cred);
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if (IS_ERR(keyring)) {
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ret = PTR_ERR(keyring);
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goto error_alloc;
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}
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/* attach the auth key to the session keyring */
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ret = key_link(keyring, authkey);
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if (ret < 0)
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goto error_link;
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/* record the UID and GID */
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sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid));
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sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid));
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/* we say which key is under construction */
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sprintf(key_str, "%d", key->serial);
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/* we specify the process's default keyrings */
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sprintf(keyring_str[0], "%d",
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cred->thread_keyring ? cred->thread_keyring->serial : 0);
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prkey = 0;
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if (cred->process_keyring)
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prkey = cred->process_keyring->serial;
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sprintf(keyring_str[1], "%d", prkey);
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session = cred->session_keyring;
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if (!session)
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session = user_session;
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sskey = session->serial;
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sprintf(keyring_str[2], "%d", sskey);
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/* set up a minimal environment */
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i = 0;
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envp[i++] = "HOME=/";
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envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
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envp[i] = NULL;
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/* set up the argument list */
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i = 0;
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argv[i++] = (char *)request_key;
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argv[i++] = (char *)rka->op;
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argv[i++] = key_str;
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argv[i++] = uid_str;
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argv[i++] = gid_str;
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argv[i++] = keyring_str[0];
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argv[i++] = keyring_str[1];
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argv[i++] = keyring_str[2];
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argv[i] = NULL;
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/* do it */
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ret = call_usermodehelper_keys(request_key, argv, envp, keyring,
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UMH_WAIT_PROC);
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kdebug("usermode -> 0x%x", ret);
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if (ret >= 0) {
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/* ret is the exit/wait code */
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if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
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key_validate(key) < 0)
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ret = -ENOKEY;
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else
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/* ignore any errors from userspace if the key was
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* instantiated */
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ret = 0;
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}
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error_link:
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key_put(keyring);
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error_alloc:
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key_put(user_session);
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error_us:
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complete_request_key(authkey, ret);
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kleave(" = %d", ret);
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return ret;
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}
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/*
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* Call out to userspace for key construction.
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*
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* Program failure is ignored in favour of key status.
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*/
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static int construct_key(struct key *key, const void *callout_info,
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size_t callout_len, void *aux,
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struct key *dest_keyring)
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{
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request_key_actor_t actor;
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struct key *authkey;
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int ret;
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kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
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/* allocate an authorisation key */
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authkey = request_key_auth_new(key, "create", callout_info, callout_len,
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dest_keyring);
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if (IS_ERR(authkey))
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return PTR_ERR(authkey);
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/* Make the call */
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actor = call_sbin_request_key;
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if (key->type->request_key)
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actor = key->type->request_key;
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ret = actor(authkey, aux);
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/* check that the actor called complete_request_key() prior to
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* returning an error */
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WARN_ON(ret < 0 &&
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!test_bit(KEY_FLAG_INVALIDATED, &authkey->flags));
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key_put(authkey);
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kleave(" = %d", ret);
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return ret;
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}
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/*
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* Get the appropriate destination keyring for the request.
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*
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* The keyring selected is returned with an extra reference upon it which the
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* caller must release.
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*/
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static int construct_get_dest_keyring(struct key **_dest_keyring)
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{
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struct request_key_auth *rka;
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const struct cred *cred = current_cred();
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struct key *dest_keyring = *_dest_keyring, *authkey;
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int ret;
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kenter("%p", dest_keyring);
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/* find the appropriate keyring */
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if (dest_keyring) {
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/* the caller supplied one */
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key_get(dest_keyring);
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} else {
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bool do_perm_check = true;
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/* use a default keyring; falling through the cases until we
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* find one that we actually have */
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switch (cred->jit_keyring) {
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case KEY_REQKEY_DEFL_DEFAULT:
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case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
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if (cred->request_key_auth) {
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authkey = cred->request_key_auth;
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down_read(&authkey->sem);
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rka = get_request_key_auth(authkey);
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if (!test_bit(KEY_FLAG_REVOKED,
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&authkey->flags))
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dest_keyring =
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key_get(rka->dest_keyring);
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up_read(&authkey->sem);
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if (dest_keyring) {
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do_perm_check = false;
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break;
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}
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}
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fallthrough;
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case KEY_REQKEY_DEFL_THREAD_KEYRING:
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dest_keyring = key_get(cred->thread_keyring);
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if (dest_keyring)
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break;
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fallthrough;
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case KEY_REQKEY_DEFL_PROCESS_KEYRING:
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dest_keyring = key_get(cred->process_keyring);
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if (dest_keyring)
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break;
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fallthrough;
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case KEY_REQKEY_DEFL_SESSION_KEYRING:
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dest_keyring = key_get(cred->session_keyring);
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if (dest_keyring)
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break;
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fallthrough;
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case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
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ret = look_up_user_keyrings(NULL, &dest_keyring);
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if (ret < 0)
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return ret;
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break;
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case KEY_REQKEY_DEFL_USER_KEYRING:
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ret = look_up_user_keyrings(&dest_keyring, NULL);
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if (ret < 0)
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return ret;
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break;
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case KEY_REQKEY_DEFL_GROUP_KEYRING:
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default:
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BUG();
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}
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/*
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* Require Write permission on the keyring. This is essential
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* because the default keyring may be the session keyring, and
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* joining a keyring only requires Search permission.
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*
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* However, this check is skipped for the "requestor keyring" so
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* that /sbin/request-key can itself use request_key() to add
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* keys to the original requestor's destination keyring.
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*/
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if (dest_keyring && do_perm_check) {
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ret = key_permission(make_key_ref(dest_keyring, 1),
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KEY_NEED_WRITE);
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if (ret) {
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key_put(dest_keyring);
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return ret;
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}
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}
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}
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*_dest_keyring = dest_keyring;
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kleave(" [dk %d]", key_serial(dest_keyring));
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return 0;
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}
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/*
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* Allocate a new key in under-construction state and attempt to link it in to
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* the requested keyring.
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*
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* May return a key that's already under construction instead if there was a
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* race between two thread calling request_key().
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*/
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static int construct_alloc_key(struct keyring_search_context *ctx,
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struct key *dest_keyring,
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unsigned long flags,
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struct key_user *user,
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struct key **_key)
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{
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struct assoc_array_edit *edit = NULL;
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struct key *key;
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key_perm_t perm;
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key_ref_t key_ref;
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int ret;
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kenter("%s,%s,,,",
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ctx->index_key.type->name, ctx->index_key.description);
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*_key = NULL;
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mutex_lock(&user->cons_lock);
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perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
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perm |= KEY_USR_VIEW;
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if (ctx->index_key.type->read)
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perm |= KEY_POS_READ;
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if (ctx->index_key.type == &key_type_keyring ||
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ctx->index_key.type->update)
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perm |= KEY_POS_WRITE;
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key = key_alloc(ctx->index_key.type, ctx->index_key.description,
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ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
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perm, flags, NULL);
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if (IS_ERR(key))
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goto alloc_failed;
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set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
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if (dest_keyring) {
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ret = __key_link_lock(dest_keyring, &ctx->index_key);
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if (ret < 0)
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goto link_lock_failed;
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ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit);
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if (ret < 0)
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goto link_prealloc_failed;
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}
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/* attach the key to the destination keyring under lock, but we do need
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* to do another check just in case someone beat us to it whilst we
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* waited for locks */
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mutex_lock(&key_construction_mutex);
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rcu_read_lock();
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key_ref = search_process_keyrings_rcu(ctx);
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rcu_read_unlock();
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if (!IS_ERR(key_ref))
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goto key_already_present;
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if (dest_keyring)
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__key_link(dest_keyring, key, &edit);
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mutex_unlock(&key_construction_mutex);
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if (dest_keyring)
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__key_link_end(dest_keyring, &ctx->index_key, edit);
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mutex_unlock(&user->cons_lock);
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*_key = key;
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kleave(" = 0 [%d]", key_serial(key));
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return 0;
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/* the key is now present - we tell the caller that we found it by
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* returning -EINPROGRESS */
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key_already_present:
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key_put(key);
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mutex_unlock(&key_construction_mutex);
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key = key_ref_to_ptr(key_ref);
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if (dest_keyring) {
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ret = __key_link_check_live_key(dest_keyring, key);
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if (ret == 0)
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__key_link(dest_keyring, key, &edit);
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__key_link_end(dest_keyring, &ctx->index_key, edit);
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if (ret < 0)
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goto link_check_failed;
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}
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mutex_unlock(&user->cons_lock);
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*_key = key;
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kleave(" = -EINPROGRESS [%d]", key_serial(key));
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return -EINPROGRESS;
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link_check_failed:
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mutex_unlock(&user->cons_lock);
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key_put(key);
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kleave(" = %d [linkcheck]", ret);
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return ret;
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link_prealloc_failed:
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__key_link_end(dest_keyring, &ctx->index_key, edit);
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link_lock_failed:
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mutex_unlock(&user->cons_lock);
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key_put(key);
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kleave(" = %d [prelink]", ret);
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return ret;
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alloc_failed:
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mutex_unlock(&user->cons_lock);
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kleave(" = %ld", PTR_ERR(key));
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return PTR_ERR(key);
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}
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/*
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* Commence key construction.
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*/
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static struct key *construct_key_and_link(struct keyring_search_context *ctx,
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const char *callout_info,
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size_t callout_len,
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void *aux,
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struct key *dest_keyring,
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unsigned long flags)
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{
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struct key_user *user;
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struct key *key;
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int ret;
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kenter("");
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if (ctx->index_key.type == &key_type_keyring)
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return ERR_PTR(-EPERM);
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ret = construct_get_dest_keyring(&dest_keyring);
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if (ret)
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goto error;
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user = key_user_lookup(current_fsuid());
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if (!user) {
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ret = -ENOMEM;
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goto error_put_dest_keyring;
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}
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ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
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key_user_put(user);
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if (ret == 0) {
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ret = construct_key(key, callout_info, callout_len, aux,
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dest_keyring);
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if (ret < 0) {
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kdebug("cons failed");
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goto construction_failed;
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}
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} else if (ret == -EINPROGRESS) {
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ret = 0;
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} else {
|
|
goto error_put_dest_keyring;
|
|
}
|
|
|
|
key_put(dest_keyring);
|
|
kleave(" = key %d", key_serial(key));
|
|
return key;
|
|
|
|
construction_failed:
|
|
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
|
|
key_put(key);
|
|
error_put_dest_keyring:
|
|
key_put(dest_keyring);
|
|
error:
|
|
kleave(" = %d", ret);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
/**
|
|
* request_key_and_link - Request a key and cache it in a keyring.
|
|
* @type: The type of key we want.
|
|
* @description: The searchable description of the key.
|
|
* @domain_tag: The domain in which the key operates.
|
|
* @callout_info: The data to pass to the instantiation upcall (or NULL).
|
|
* @callout_len: The length of callout_info.
|
|
* @aux: Auxiliary data for the upcall.
|
|
* @dest_keyring: Where to cache the key.
|
|
* @flags: Flags to key_alloc().
|
|
*
|
|
* A key matching the specified criteria (type, description, domain_tag) is
|
|
* searched for in the process's keyrings and returned with its usage count
|
|
* incremented if found. Otherwise, if callout_info is not NULL, a key will be
|
|
* allocated and some service (probably in userspace) will be asked to
|
|
* instantiate it.
|
|
*
|
|
* If successfully found or created, the key will be linked to the destination
|
|
* keyring if one is provided.
|
|
*
|
|
* Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
|
|
* or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
|
|
* found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
|
|
* if insufficient key quota was available to create a new key; or -ENOMEM if
|
|
* insufficient memory was available.
|
|
*
|
|
* If the returned key was created, then it may still be under construction,
|
|
* and wait_for_key_construction() should be used to wait for that to complete.
|
|
*/
|
|
struct key *request_key_and_link(struct key_type *type,
|
|
const char *description,
|
|
struct key_tag *domain_tag,
|
|
const void *callout_info,
|
|
size_t callout_len,
|
|
void *aux,
|
|
struct key *dest_keyring,
|
|
unsigned long flags)
|
|
{
|
|
struct keyring_search_context ctx = {
|
|
.index_key.type = type,
|
|
.index_key.domain_tag = domain_tag,
|
|
.index_key.description = description,
|
|
.index_key.desc_len = strlen(description),
|
|
.cred = current_cred(),
|
|
.match_data.cmp = key_default_cmp,
|
|
.match_data.raw_data = description,
|
|
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
|
|
.flags = (KEYRING_SEARCH_DO_STATE_CHECK |
|
|
KEYRING_SEARCH_SKIP_EXPIRED |
|
|
KEYRING_SEARCH_RECURSE),
|
|
};
|
|
struct key *key;
|
|
key_ref_t key_ref;
|
|
int ret;
|
|
|
|
kenter("%s,%s,%p,%zu,%p,%p,%lx",
|
|
ctx.index_key.type->name, ctx.index_key.description,
|
|
callout_info, callout_len, aux, dest_keyring, flags);
|
|
|
|
if (type->match_preparse) {
|
|
ret = type->match_preparse(&ctx.match_data);
|
|
if (ret < 0) {
|
|
key = ERR_PTR(ret);
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
key = check_cached_key(&ctx);
|
|
if (key)
|
|
goto error_free;
|
|
|
|
/* search all the process keyrings for a key */
|
|
rcu_read_lock();
|
|
key_ref = search_process_keyrings_rcu(&ctx);
|
|
rcu_read_unlock();
|
|
|
|
if (!IS_ERR(key_ref)) {
|
|
if (dest_keyring) {
|
|
ret = key_task_permission(key_ref, current_cred(),
|
|
KEY_NEED_LINK);
|
|
if (ret < 0) {
|
|
key_ref_put(key_ref);
|
|
key = ERR_PTR(ret);
|
|
goto error_free;
|
|
}
|
|
}
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
if (dest_keyring) {
|
|
ret = key_link(dest_keyring, key);
|
|
if (ret < 0) {
|
|
key_put(key);
|
|
key = ERR_PTR(ret);
|
|
goto error_free;
|
|
}
|
|
}
|
|
|
|
/* Only cache the key on immediate success */
|
|
cache_requested_key(key);
|
|
} else if (PTR_ERR(key_ref) != -EAGAIN) {
|
|
key = ERR_CAST(key_ref);
|
|
} else {
|
|
/* the search failed, but the keyrings were searchable, so we
|
|
* should consult userspace if we can */
|
|
key = ERR_PTR(-ENOKEY);
|
|
if (!callout_info)
|
|
goto error_free;
|
|
|
|
key = construct_key_and_link(&ctx, callout_info, callout_len,
|
|
aux, dest_keyring, flags);
|
|
}
|
|
|
|
error_free:
|
|
if (type->match_free)
|
|
type->match_free(&ctx.match_data);
|
|
error:
|
|
kleave(" = %p", key);
|
|
return key;
|
|
}
|
|
|
|
/**
|
|
* wait_for_key_construction - Wait for construction of a key to complete
|
|
* @key: The key being waited for.
|
|
* @intr: Whether to wait interruptibly.
|
|
*
|
|
* Wait for a key to finish being constructed.
|
|
*
|
|
* Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY
|
|
* if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was
|
|
* revoked or expired.
|
|
*/
|
|
int wait_for_key_construction(struct key *key, bool intr)
|
|
{
|
|
int ret;
|
|
|
|
ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
|
|
intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
|
|
if (ret)
|
|
return -ERESTARTSYS;
|
|
ret = key_read_state(key);
|
|
if (ret < 0)
|
|
return ret;
|
|
return key_validate(key);
|
|
}
|
|
EXPORT_SYMBOL(wait_for_key_construction);
|
|
|
|
/**
|
|
* request_key_tag - Request a key and wait for construction
|
|
* @type: Type of key.
|
|
* @description: The searchable description of the key.
|
|
* @domain_tag: The domain in which the key operates.
|
|
* @callout_info: The data to pass to the instantiation upcall (or NULL).
|
|
*
|
|
* As for request_key_and_link() except that it does not add the returned key
|
|
* to a keyring if found, new keys are always allocated in the user's quota,
|
|
* the callout_info must be a NUL-terminated string and no auxiliary data can
|
|
* be passed.
|
|
*
|
|
* Furthermore, it then works as wait_for_key_construction() to wait for the
|
|
* completion of keys undergoing construction with a non-interruptible wait.
|
|
*/
|
|
struct key *request_key_tag(struct key_type *type,
|
|
const char *description,
|
|
struct key_tag *domain_tag,
|
|
const char *callout_info)
|
|
{
|
|
struct key *key;
|
|
size_t callout_len = 0;
|
|
int ret;
|
|
|
|
if (callout_info)
|
|
callout_len = strlen(callout_info);
|
|
key = request_key_and_link(type, description, domain_tag,
|
|
callout_info, callout_len,
|
|
NULL, NULL, KEY_ALLOC_IN_QUOTA);
|
|
if (!IS_ERR(key)) {
|
|
ret = wait_for_key_construction(key, false);
|
|
if (ret < 0) {
|
|
key_put(key);
|
|
return ERR_PTR(ret);
|
|
}
|
|
}
|
|
return key;
|
|
}
|
|
EXPORT_SYMBOL(request_key_tag);
|
|
|
|
/**
|
|
* request_key_with_auxdata - Request a key with auxiliary data for the upcaller
|
|
* @type: The type of key we want.
|
|
* @description: The searchable description of the key.
|
|
* @domain_tag: The domain in which the key operates.
|
|
* @callout_info: The data to pass to the instantiation upcall (or NULL).
|
|
* @callout_len: The length of callout_info.
|
|
* @aux: Auxiliary data for the upcall.
|
|
*
|
|
* As for request_key_and_link() except that it does not add the returned key
|
|
* to a keyring if found and new keys are always allocated in the user's quota.
|
|
*
|
|
* Furthermore, it then works as wait_for_key_construction() to wait for the
|
|
* completion of keys undergoing construction with a non-interruptible wait.
|
|
*/
|
|
struct key *request_key_with_auxdata(struct key_type *type,
|
|
const char *description,
|
|
struct key_tag *domain_tag,
|
|
const void *callout_info,
|
|
size_t callout_len,
|
|
void *aux)
|
|
{
|
|
struct key *key;
|
|
int ret;
|
|
|
|
key = request_key_and_link(type, description, domain_tag,
|
|
callout_info, callout_len,
|
|
aux, NULL, KEY_ALLOC_IN_QUOTA);
|
|
if (!IS_ERR(key)) {
|
|
ret = wait_for_key_construction(key, false);
|
|
if (ret < 0) {
|
|
key_put(key);
|
|
return ERR_PTR(ret);
|
|
}
|
|
}
|
|
return key;
|
|
}
|
|
EXPORT_SYMBOL(request_key_with_auxdata);
|
|
|
|
/**
|
|
* request_key_rcu - Request key from RCU-read-locked context
|
|
* @type: The type of key we want.
|
|
* @description: The name of the key we want.
|
|
* @domain_tag: The domain in which the key operates.
|
|
*
|
|
* Request a key from a context that we may not sleep in (such as RCU-mode
|
|
* pathwalk). Keys under construction are ignored.
|
|
*
|
|
* Return a pointer to the found key if successful, -ENOKEY if we couldn't find
|
|
* a key or some other error if the key found was unsuitable or inaccessible.
|
|
*/
|
|
struct key *request_key_rcu(struct key_type *type,
|
|
const char *description,
|
|
struct key_tag *domain_tag)
|
|
{
|
|
struct keyring_search_context ctx = {
|
|
.index_key.type = type,
|
|
.index_key.domain_tag = domain_tag,
|
|
.index_key.description = description,
|
|
.index_key.desc_len = strlen(description),
|
|
.cred = current_cred(),
|
|
.match_data.cmp = key_default_cmp,
|
|
.match_data.raw_data = description,
|
|
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
|
|
.flags = (KEYRING_SEARCH_DO_STATE_CHECK |
|
|
KEYRING_SEARCH_SKIP_EXPIRED),
|
|
};
|
|
struct key *key;
|
|
key_ref_t key_ref;
|
|
|
|
kenter("%s,%s", type->name, description);
|
|
|
|
key = check_cached_key(&ctx);
|
|
if (key)
|
|
return key;
|
|
|
|
/* search all the process keyrings for a key */
|
|
key_ref = search_process_keyrings_rcu(&ctx);
|
|
if (IS_ERR(key_ref)) {
|
|
key = ERR_CAST(key_ref);
|
|
if (PTR_ERR(key_ref) == -EAGAIN)
|
|
key = ERR_PTR(-ENOKEY);
|
|
} else {
|
|
key = key_ref_to_ptr(key_ref);
|
|
cache_requested_key(key);
|
|
}
|
|
|
|
kleave(" = %p", key);
|
|
return key;
|
|
}
|
|
EXPORT_SYMBOL(request_key_rcu);
|