![Vegard Nossum](/assets/img/avatar_default.png)
Plug this leak. Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <stable@kernel.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1306 lines
30 KiB
C
1306 lines
30 KiB
C
/* keyctl.c: userspace keyctl operations
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*
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* Copyright (C) 2004-5 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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/syscalls.h>
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#include <linux/keyctl.h>
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#include <linux/fs.h>
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#include <linux/capability.h>
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#include <linux/string.h>
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#include <linux/err.h>
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#include <linux/vmalloc.h>
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#include <linux/security.h>
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#include <asm/uaccess.h>
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#include "internal.h"
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static int key_get_type_from_user(char *type,
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const char __user *_type,
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unsigned len)
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{
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int ret;
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ret = strncpy_from_user(type, _type, len);
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if (ret < 0)
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return -EFAULT;
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if (ret == 0 || ret >= len)
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return -EINVAL;
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if (type[0] == '.')
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return -EPERM;
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type[len - 1] = '\0';
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return 0;
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}
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/*****************************************************************************/
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/*
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* extract the description of a new key from userspace and either add it as a
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* new key to the specified keyring or update a matching key in that keyring
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* - the keyring must be writable
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* - returns the new key's serial number
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* - implements add_key()
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*/
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SYSCALL_DEFINE5(add_key, const char __user *, _type,
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const char __user *, _description,
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const void __user *, _payload,
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size_t, plen,
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key_serial_t, ringid)
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{
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key_ref_t keyring_ref, key_ref;
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char type[32], *description;
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void *payload;
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long ret;
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bool vm;
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ret = -EINVAL;
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if (plen > 1024 * 1024 - 1)
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goto error;
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/* draw all the data into kernel space */
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ret = key_get_type_from_user(type, _type, sizeof(type));
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if (ret < 0)
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goto error;
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description = strndup_user(_description, PAGE_SIZE);
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if (IS_ERR(description)) {
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ret = PTR_ERR(description);
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goto error;
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}
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/* pull the payload in if one was supplied */
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payload = NULL;
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vm = false;
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if (_payload) {
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ret = -ENOMEM;
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payload = kmalloc(plen, GFP_KERNEL);
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if (!payload) {
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if (plen <= PAGE_SIZE)
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goto error2;
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vm = true;
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payload = vmalloc(plen);
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if (!payload)
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goto error2;
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}
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ret = -EFAULT;
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if (copy_from_user(payload, _payload, plen) != 0)
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goto error3;
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}
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/* find the target keyring (which must be writable) */
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keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
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if (IS_ERR(keyring_ref)) {
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ret = PTR_ERR(keyring_ref);
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goto error3;
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}
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/* create or update the requested key and add it to the target
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* keyring */
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key_ref = key_create_or_update(keyring_ref, type, description,
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payload, plen, KEY_PERM_UNDEF,
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KEY_ALLOC_IN_QUOTA);
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if (!IS_ERR(key_ref)) {
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ret = key_ref_to_ptr(key_ref)->serial;
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key_ref_put(key_ref);
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}
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else {
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ret = PTR_ERR(key_ref);
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}
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key_ref_put(keyring_ref);
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error3:
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if (!vm)
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kfree(payload);
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else
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vfree(payload);
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error2:
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kfree(description);
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error:
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return ret;
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} /* end sys_add_key() */
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/*****************************************************************************/
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/*
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* search the process keyrings for a matching key
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* - nested keyrings may also be searched if they have Search permission
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* - if a key is found, it will be attached to the destination keyring if
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* there's one specified
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* - /sbin/request-key will be invoked if _callout_info is non-NULL
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* - the _callout_info string will be passed to /sbin/request-key
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* - if the _callout_info string is empty, it will be rendered as "-"
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* - implements request_key()
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*/
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SYSCALL_DEFINE4(request_key, const char __user *, _type,
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const char __user *, _description,
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const char __user *, _callout_info,
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key_serial_t, destringid)
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{
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struct key_type *ktype;
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struct key *key;
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key_ref_t dest_ref;
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size_t callout_len;
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char type[32], *description, *callout_info;
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long ret;
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/* pull the type into kernel space */
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ret = key_get_type_from_user(type, _type, sizeof(type));
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if (ret < 0)
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goto error;
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/* pull the description into kernel space */
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description = strndup_user(_description, PAGE_SIZE);
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if (IS_ERR(description)) {
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ret = PTR_ERR(description);
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goto error;
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}
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/* pull the callout info into kernel space */
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callout_info = NULL;
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callout_len = 0;
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if (_callout_info) {
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callout_info = strndup_user(_callout_info, PAGE_SIZE);
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if (IS_ERR(callout_info)) {
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ret = PTR_ERR(callout_info);
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goto error2;
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}
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callout_len = strlen(callout_info);
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}
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/* get the destination keyring if specified */
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dest_ref = NULL;
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if (destringid) {
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dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE);
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if (IS_ERR(dest_ref)) {
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ret = PTR_ERR(dest_ref);
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goto error3;
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}
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}
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/* find the key type */
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ktype = key_type_lookup(type);
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if (IS_ERR(ktype)) {
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ret = PTR_ERR(ktype);
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goto error4;
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}
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/* do the search */
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key = request_key_and_link(ktype, description, callout_info,
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callout_len, NULL, key_ref_to_ptr(dest_ref),
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KEY_ALLOC_IN_QUOTA);
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if (IS_ERR(key)) {
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ret = PTR_ERR(key);
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goto error5;
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}
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ret = key->serial;
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key_put(key);
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error5:
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key_type_put(ktype);
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error4:
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key_ref_put(dest_ref);
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error3:
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kfree(callout_info);
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error2:
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kfree(description);
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error:
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return ret;
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} /* end sys_request_key() */
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/*****************************************************************************/
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/*
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* get the ID of the specified process keyring
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* - the keyring must have search permission to be found
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* - implements keyctl(KEYCTL_GET_KEYRING_ID)
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*/
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long keyctl_get_keyring_ID(key_serial_t id, int create)
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{
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key_ref_t key_ref;
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long ret;
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key_ref = lookup_user_key(id, create, 0, KEY_SEARCH);
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if (IS_ERR(key_ref)) {
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ret = PTR_ERR(key_ref);
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goto error;
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}
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ret = key_ref_to_ptr(key_ref)->serial;
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key_ref_put(key_ref);
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error:
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return ret;
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} /* end keyctl_get_keyring_ID() */
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/*****************************************************************************/
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/*
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* join the session keyring
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* - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING)
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*/
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long keyctl_join_session_keyring(const char __user *_name)
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{
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char *name;
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long ret;
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/* fetch the name from userspace */
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name = NULL;
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if (_name) {
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name = strndup_user(_name, PAGE_SIZE);
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if (IS_ERR(name)) {
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ret = PTR_ERR(name);
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goto error;
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}
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}
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/* join the session */
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ret = join_session_keyring(name);
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kfree(name);
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error:
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return ret;
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} /* end keyctl_join_session_keyring() */
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/*****************************************************************************/
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/*
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* update a key's data payload
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* - the key must be writable
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* - implements keyctl(KEYCTL_UPDATE)
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*/
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long keyctl_update_key(key_serial_t id,
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const void __user *_payload,
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size_t plen)
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{
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key_ref_t key_ref;
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void *payload;
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long ret;
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ret = -EINVAL;
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if (plen > PAGE_SIZE)
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goto error;
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/* pull the payload in if one was supplied */
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payload = NULL;
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if (_payload) {
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ret = -ENOMEM;
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payload = kmalloc(plen, GFP_KERNEL);
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if (!payload)
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goto error;
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ret = -EFAULT;
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if (copy_from_user(payload, _payload, plen) != 0)
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goto error2;
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}
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/* find the target key (which must be writable) */
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key_ref = lookup_user_key(id, 0, 0, KEY_WRITE);
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if (IS_ERR(key_ref)) {
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ret = PTR_ERR(key_ref);
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goto error2;
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}
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/* update the key */
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ret = key_update(key_ref, payload, plen);
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key_ref_put(key_ref);
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error2:
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kfree(payload);
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error:
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return ret;
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} /* end keyctl_update_key() */
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/*****************************************************************************/
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/*
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* revoke a key
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* - the key must be writable
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* - implements keyctl(KEYCTL_REVOKE)
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*/
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long keyctl_revoke_key(key_serial_t id)
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{
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key_ref_t key_ref;
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long ret;
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key_ref = lookup_user_key(id, 0, 0, KEY_WRITE);
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if (IS_ERR(key_ref)) {
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ret = PTR_ERR(key_ref);
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goto error;
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}
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key_revoke(key_ref_to_ptr(key_ref));
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ret = 0;
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key_ref_put(key_ref);
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error:
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return ret;
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} /* end keyctl_revoke_key() */
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/*****************************************************************************/
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/*
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* clear the specified process keyring
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* - the keyring must be writable
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* - implements keyctl(KEYCTL_CLEAR)
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*/
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long keyctl_keyring_clear(key_serial_t ringid)
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{
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key_ref_t keyring_ref;
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long ret;
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keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
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if (IS_ERR(keyring_ref)) {
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ret = PTR_ERR(keyring_ref);
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goto error;
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}
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ret = keyring_clear(key_ref_to_ptr(keyring_ref));
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key_ref_put(keyring_ref);
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error:
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return ret;
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} /* end keyctl_keyring_clear() */
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/*****************************************************************************/
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/*
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* link a key into a keyring
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* - the keyring must be writable
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* - the key must be linkable
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* - implements keyctl(KEYCTL_LINK)
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*/
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long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
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{
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key_ref_t keyring_ref, key_ref;
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long ret;
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keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
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if (IS_ERR(keyring_ref)) {
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ret = PTR_ERR(keyring_ref);
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goto error;
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}
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key_ref = lookup_user_key(id, 1, 0, KEY_LINK);
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if (IS_ERR(key_ref)) {
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ret = PTR_ERR(key_ref);
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goto error2;
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}
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ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
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key_ref_put(key_ref);
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error2:
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key_ref_put(keyring_ref);
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error:
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return ret;
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} /* end keyctl_keyring_link() */
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/*****************************************************************************/
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/*
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* unlink the first attachment of a key from a keyring
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* - the keyring must be writable
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* - we don't need any permissions on the key
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* - implements keyctl(KEYCTL_UNLINK)
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*/
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long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
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{
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key_ref_t keyring_ref, key_ref;
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long ret;
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keyring_ref = lookup_user_key(ringid, 0, 0, KEY_WRITE);
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if (IS_ERR(keyring_ref)) {
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ret = PTR_ERR(keyring_ref);
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goto error;
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}
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key_ref = lookup_user_key(id, 0, 0, 0);
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if (IS_ERR(key_ref)) {
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ret = PTR_ERR(key_ref);
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goto error2;
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}
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ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
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key_ref_put(key_ref);
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error2:
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key_ref_put(keyring_ref);
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error:
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return ret;
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|
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} /* end keyctl_keyring_unlink() */
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|
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/*****************************************************************************/
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/*
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* describe a user key
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* - the key must have view permission
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* - if there's a buffer, we place up to buflen bytes of data into it
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* - unless there's an error, we return the amount of description available,
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* irrespective of how much we may have copied
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* - the description is formatted thus:
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* type;uid;gid;perm;description<NUL>
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* - implements keyctl(KEYCTL_DESCRIBE)
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*/
|
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long keyctl_describe_key(key_serial_t keyid,
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char __user *buffer,
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size_t buflen)
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|
{
|
|
struct key *key, *instkey;
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key_ref_t key_ref;
|
|
char *tmpbuf;
|
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long ret;
|
|
|
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key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW);
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if (IS_ERR(key_ref)) {
|
|
/* viewing a key under construction is permitted if we have the
|
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* authorisation token handy */
|
|
if (PTR_ERR(key_ref) == -EACCES) {
|
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instkey = key_get_instantiation_authkey(keyid);
|
|
if (!IS_ERR(instkey)) {
|
|
key_put(instkey);
|
|
key_ref = lookup_user_key(keyid,
|
|
0, 1, 0);
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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,
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|
"%s;%d;%d;%08x;%s",
|
|
key_ref_to_ptr(key_ref)->type->name,
|
|
key_ref_to_ptr(key_ref)->uid,
|
|
key_ref_to_ptr(key_ref)->gid,
|
|
key_ref_to_ptr(key_ref)->perm,
|
|
key_ref_to_ptr(key_ref)->description ?
|
|
key_ref_to_ptr(key_ref)->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;
|
|
|
|
} /* end keyctl_describe_key() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* search the specified keyring for a matching key
|
|
* - the start keyring must be searchable
|
|
* - nested keyrings may also be searched if they are searchable
|
|
* - only keys with search permission may be found
|
|
* - if a key is found, it will be attached to the destination keyring if
|
|
* there's one specified
|
|
* - implements keyctl(KEYCTL_SEARCH)
|
|
*/
|
|
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, 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, 1, 0, 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;
|
|
|
|
} /* end keyctl_keyring_search() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* read a user key's payload
|
|
* - the keyring must be readable or the key must be searchable from the
|
|
* process's keyrings
|
|
* - if there's a buffer, we place up to buflen bytes of data into it
|
|
* - unless there's an error, we return the amount of data in the key,
|
|
* irrespective of how much we may have copied
|
|
* - implements keyctl(KEYCTL_READ)
|
|
*/
|
|
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, 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;
|
|
|
|
} /* end keyctl_read_key() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* change the ownership of a key
|
|
* - the keyring owned by the changer
|
|
* - if the uid or gid is -1, then that parameter is not changed
|
|
* - implements keyctl(KEYCTL_CHOWN)
|
|
*/
|
|
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, 1, 1, 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);
|
|
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;
|
|
|
|
} /* end keyctl_chown_key() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* change the permission mask on a key
|
|
* - the keyring owned by the changer
|
|
* - implements keyctl(KEYCTL_SETPERM)
|
|
*/
|
|
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, 1, 1, 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;
|
|
|
|
} /* end keyctl_setperm_key() */
|
|
|
|
/*
|
|
* get the destination keyring for instantiation
|
|
*/
|
|
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, 1, 0, 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 = 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);
|
|
}
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* instantiate the key with the specified payload, and, if one is given, link
|
|
* the key into the keyring
|
|
*/
|
|
long keyctl_instantiate_key(key_serial_t id,
|
|
const void __user *_payload,
|
|
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) {
|
|
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 = -EFAULT;
|
|
if (copy_from_user(payload, _payload, plen) != 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;
|
|
|
|
} /* end keyctl_instantiate_key() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* negatively instantiate the key with the given timeout (in seconds), and, if
|
|
* one is given, link the key into the keyring
|
|
*/
|
|
long keyctl_negate_key(key_serial_t id, unsigned timeout, 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,%d", id, timeout, ringid);
|
|
|
|
/* 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_negate_and_link(rka->target_key, timeout,
|
|
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;
|
|
|
|
} /* end keyctl_negate_key() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* set the default keyring in which request_key() will cache keys
|
|
* - return the old setting
|
|
*/
|
|
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 -EINVAL;
|
|
|
|
} /* end keyctl_set_reqkey_keyring() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* set or clear the timeout for a key
|
|
*/
|
|
long keyctl_set_timeout(key_serial_t id, unsigned timeout)
|
|
{
|
|
struct timespec now;
|
|
struct key *key;
|
|
key_ref_t key_ref;
|
|
time_t expiry;
|
|
long ret;
|
|
|
|
key_ref = lookup_user_key(id, 1, 1, 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 races */
|
|
down_write(&key->sem);
|
|
|
|
expiry = 0;
|
|
if (timeout > 0) {
|
|
now = current_kernel_time();
|
|
expiry = now.tv_sec + timeout;
|
|
}
|
|
|
|
key->expiry = expiry;
|
|
|
|
up_write(&key->sem);
|
|
key_put(key);
|
|
|
|
ret = 0;
|
|
error:
|
|
return ret;
|
|
|
|
} /* end keyctl_set_timeout() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* assume the authority to instantiate the specified 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;
|
|
|
|
} /* end keyctl_assume_authority() */
|
|
|
|
/*
|
|
* get the security label of a key
|
|
* - the key must grant us view permission
|
|
* - if there's a buffer, we place up to buflen bytes of data into it
|
|
* - unless there's an error, we return the amount of information available,
|
|
* irrespective of how much we may have copied (including the terminal NUL)
|
|
* - implements keyctl(KEYCTL_GET_SECURITY)
|
|
*/
|
|
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, 0, 1, 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(key_ref);
|
|
key_put(instkey);
|
|
|
|
key_ref = lookup_user_key(keyid, 0, 1, 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;
|
|
}
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* 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);
|
|
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
} /* end sys_keyctl() */
|