![Linus Torvalds](/assets/img/avatar_default.png)
Pull module signing support from Rusty Russell: "module signing is the highlight, but it's an all-over David Howells frenzy..." Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG. * 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits) X.509: Fix indefinite length element skip error handling X.509: Convert some printk calls to pr_devel asymmetric keys: fix printk format warning MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking MODSIGN: Make mrproper should remove generated files. MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs MODSIGN: Use the same digest for the autogen key sig as for the module sig MODSIGN: Sign modules during the build process MODSIGN: Provide a script for generating a key ID from an X.509 cert MODSIGN: Implement module signature checking MODSIGN: Provide module signing public keys to the kernel MODSIGN: Automatically generate module signing keys if missing MODSIGN: Provide Kconfig options MODSIGN: Provide gitignore and make clean rules for extra files MODSIGN: Add FIPS policy module: signature checking hook X.509: Add a crypto key parser for binary (DER) X.509 certificates MPILIB: Provide a function to read raw data into an MPI X.509: Add an ASN.1 decoder X.509: Add simple ASN.1 grammar compiler ...
1672 lines
40 KiB
C
1672 lines
40 KiB
C
/* Userspace key control 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/key.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 ret;
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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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* 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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*
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* If the description is NULL or an empty string, the key type is asked to
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* generate one from the payload.
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*
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* The keyring must be writable so that we can attach the key to it.
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*
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* If successful, the new key's serial number is returned, otherwise an error
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* code is returned.
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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 = NULL;
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if (_description) {
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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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if (!*description) {
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kfree(description);
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description = NULL;
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}
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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 | __GFP_NOWARN);
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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, KEY_LOOKUP_CREATE, 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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}
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/*
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* Search the process keyrings and keyring trees linked from those for a
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* matching key. Keyrings must have appropriate Search permission to be
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* searched.
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*
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* If a key is found, it will be attached to the destination keyring if there's
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* one specified and the serial number of the key will be returned.
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*
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* If no key is found, /sbin/request-key will be invoked if _callout_info is
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* non-NULL in an attempt to create a key. The _callout_info string will be
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* passed to /sbin/request-key to aid with completing the request. If the
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* _callout_info string is "" then it will be changed to "-".
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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, KEY_LOOKUP_CREATE,
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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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/* wait for the key to finish being constructed */
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ret = wait_for_key_construction(key, 1);
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if (ret < 0)
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goto error6;
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ret = key->serial;
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error6:
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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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}
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/*
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* Get the ID of the specified process keyring.
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*
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* The requested keyring must have search permission to be found.
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*
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* If successful, the ID of the requested keyring will be returned.
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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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unsigned long lflags;
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long ret;
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lflags = create ? KEY_LOOKUP_CREATE : 0;
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key_ref = lookup_user_key(id, lflags, 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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}
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/*
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* Join a (named) session keyring.
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*
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* Create and join an anonymous session keyring or join a named session
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* keyring, creating it if necessary. A named session keyring must have Search
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* permission for it to be joined. Session keyrings without this permit will
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* be skipped over.
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*
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* If successful, the ID of the joined session keyring will be returned.
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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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}
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/*
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* Update a key's data payload from the given data.
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*
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* The key must grant the caller Write permission and the key type must support
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* updating for this to work. A negative key can be positively instantiated
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* with this call.
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*
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* If successful, 0 will be returned. If the key type does not support
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* updating, then -EOPNOTSUPP will be returned.
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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, 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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}
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|
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/*
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* Revoke a key.
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*
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* The key must be grant the caller Write or Setattr permission for this to
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* work. The key type should give up its quota claim when revoked. The key
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* and any links to the key will be automatically garbage collected after a
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* certain amount of time (/proc/sys/kernel/keys/gc_delay).
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*
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* If successful, 0 is returned.
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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, KEY_WRITE);
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if (IS_ERR(key_ref)) {
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ret = PTR_ERR(key_ref);
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if (ret != -EACCES)
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goto error;
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key_ref = lookup_user_key(id, 0, KEY_SETATTR);
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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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}
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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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}
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|
|
/*
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* Invalidate a key.
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*
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* The key must be grant the caller Invalidate permission for this to work.
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* The key and any links to the key will be automatically garbage collected
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* immediately.
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*
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* If successful, 0 is returned.
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*/
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long keyctl_invalidate_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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kenter("%d", id);
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key_ref = lookup_user_key(id, 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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key_invalidate(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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kleave(" = %ld", ret);
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return ret;
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}
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|
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/*
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* Clear the specified keyring, creating an empty process keyring if one of the
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* special keyring IDs is used.
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*
|
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* The keyring must grant the caller Write permission for this to work. If
|
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* successful, 0 will be returned.
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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, KEY_LOOKUP_CREATE, KEY_WRITE);
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if (IS_ERR(keyring_ref)) {
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ret = PTR_ERR(keyring_ref);
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|
|
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/* Root is permitted to invalidate certain special keyrings */
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if (capable(CAP_SYS_ADMIN)) {
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keyring_ref = lookup_user_key(ringid, 0, 0);
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if (IS_ERR(keyring_ref))
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goto error;
|
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if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
|
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&key_ref_to_ptr(keyring_ref)->flags))
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goto clear;
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goto error_put;
|
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}
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|
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goto error;
|
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}
|
|
|
|
clear:
|
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ret = keyring_clear(key_ref_to_ptr(keyring_ref));
|
|
error_put:
|
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key_ref_put(keyring_ref);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Create a link from a keyring to a key if there's no matching key in the
|
|
* keyring, otherwise replace the link to the matching key with a link to the
|
|
* new key.
|
|
*
|
|
* The key must grant the caller Link permission and the the keyring must grant
|
|
* the caller Write permission. Furthermore, if an additional link is created,
|
|
* the keyring's quota will be extended.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
|
|
{
|
|
key_ref_t keyring_ref, key_ref;
|
|
long ret;
|
|
|
|
keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
|
|
if (IS_ERR(keyring_ref)) {
|
|
ret = PTR_ERR(keyring_ref);
|
|
goto error;
|
|
}
|
|
|
|
key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
|
|
if (IS_ERR(key_ref)) {
|
|
ret = PTR_ERR(key_ref);
|
|
goto error2;
|
|
}
|
|
|
|
ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
|
|
|
|
key_ref_put(key_ref);
|
|
error2:
|
|
key_ref_put(keyring_ref);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Unlink a key from a keyring.
|
|
*
|
|
* The keyring must grant the caller Write permission for this to work; the key
|
|
* itself need not grant the caller anything. If the last link to a key is
|
|
* removed then that key will be scheduled for destruction.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
|
|
{
|
|
key_ref_t keyring_ref, key_ref;
|
|
long ret;
|
|
|
|
keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
|
|
if (IS_ERR(keyring_ref)) {
|
|
ret = PTR_ERR(keyring_ref);
|
|
goto error;
|
|
}
|
|
|
|
key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
|
|
if (IS_ERR(key_ref)) {
|
|
ret = PTR_ERR(key_ref);
|
|
goto error2;
|
|
}
|
|
|
|
ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
|
|
|
|
key_ref_put(key_ref);
|
|
error2:
|
|
key_ref_put(keyring_ref);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Return a description of a key to userspace.
|
|
*
|
|
* The key must grant the caller View permission for this to work.
|
|
*
|
|
* If there's a buffer, we place up to buflen bytes of data into it formatted
|
|
* in the following way:
|
|
*
|
|
* type;uid;gid;perm;description<NUL>
|
|
*
|
|
* If successful, we return the amount of description available, irrespective
|
|
* of how much we may have copied into the buffer.
|
|
*/
|
|
long keyctl_describe_key(key_serial_t keyid,
|
|
char __user *buffer,
|
|
size_t buflen)
|
|
{
|
|
struct key *key, *instkey;
|
|
key_ref_t key_ref;
|
|
char *tmpbuf;
|
|
long ret;
|
|
|
|
key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
|
|
if (IS_ERR(key_ref)) {
|
|
/* viewing a key under construction is permitted if we have the
|
|
* authorisation token handy */
|
|
if (PTR_ERR(key_ref) == -EACCES) {
|
|
instkey = key_get_instantiation_authkey(keyid);
|
|
if (!IS_ERR(instkey)) {
|
|
key_put(instkey);
|
|
key_ref = lookup_user_key(keyid,
|
|
KEY_LOOKUP_PARTIAL,
|
|
0);
|
|
if (!IS_ERR(key_ref))
|
|
goto okay;
|
|
}
|
|
}
|
|
|
|
ret = PTR_ERR(key_ref);
|
|
goto error;
|
|
}
|
|
|
|
okay:
|
|
/* calculate how much description we're going to return */
|
|
ret = -ENOMEM;
|
|
tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!tmpbuf)
|
|
goto error2;
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
|
|
ret = snprintf(tmpbuf, PAGE_SIZE - 1,
|
|
"%s;%d;%d;%08x;%s",
|
|
key->type->name,
|
|
from_kuid_munged(current_user_ns(), key->uid),
|
|
from_kgid_munged(current_user_ns(), key->gid),
|
|
key->perm,
|
|
key->description ?: "");
|
|
|
|
/* include a NUL char at the end of the data */
|
|
if (ret > PAGE_SIZE - 1)
|
|
ret = PAGE_SIZE - 1;
|
|
tmpbuf[ret] = 0;
|
|
ret++;
|
|
|
|
/* consider returning the data */
|
|
if (buffer && buflen > 0) {
|
|
if (buflen > ret)
|
|
buflen = ret;
|
|
|
|
if (copy_to_user(buffer, tmpbuf, buflen) != 0)
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
kfree(tmpbuf);
|
|
error2:
|
|
key_ref_put(key_ref);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Search the specified keyring and any keyrings it links to for a matching
|
|
* key. Only keyrings that grant the caller Search permission will be searched
|
|
* (this includes the starting keyring). Only keys with Search permission can
|
|
* be found.
|
|
*
|
|
* If successful, the found key will be linked to the destination keyring if
|
|
* supplied and the key has Link permission, and the found key ID will be
|
|
* returned.
|
|
*/
|
|
long keyctl_keyring_search(key_serial_t ringid,
|
|
const char __user *_type,
|
|
const char __user *_description,
|
|
key_serial_t destringid)
|
|
{
|
|
struct key_type *ktype;
|
|
key_ref_t keyring_ref, key_ref, dest_ref;
|
|
char type[32], *description;
|
|
long ret;
|
|
|
|
/* pull the type and description into kernel space */
|
|
ret = key_get_type_from_user(type, _type, sizeof(type));
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
description = strndup_user(_description, PAGE_SIZE);
|
|
if (IS_ERR(description)) {
|
|
ret = PTR_ERR(description);
|
|
goto error;
|
|
}
|
|
|
|
/* get the keyring at which to begin the search */
|
|
keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
|
|
if (IS_ERR(keyring_ref)) {
|
|
ret = PTR_ERR(keyring_ref);
|
|
goto error2;
|
|
}
|
|
|
|
/* get the destination keyring if specified */
|
|
dest_ref = NULL;
|
|
if (destringid) {
|
|
dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
|
|
KEY_WRITE);
|
|
if (IS_ERR(dest_ref)) {
|
|
ret = PTR_ERR(dest_ref);
|
|
goto error3;
|
|
}
|
|
}
|
|
|
|
/* find the key type */
|
|
ktype = key_type_lookup(type);
|
|
if (IS_ERR(ktype)) {
|
|
ret = PTR_ERR(ktype);
|
|
goto error4;
|
|
}
|
|
|
|
/* do the search */
|
|
key_ref = keyring_search(keyring_ref, ktype, description);
|
|
if (IS_ERR(key_ref)) {
|
|
ret = PTR_ERR(key_ref);
|
|
|
|
/* treat lack or presence of a negative key the same */
|
|
if (ret == -EAGAIN)
|
|
ret = -ENOKEY;
|
|
goto error5;
|
|
}
|
|
|
|
/* link the resulting key to the destination keyring if we can */
|
|
if (dest_ref) {
|
|
ret = key_permission(key_ref, KEY_LINK);
|
|
if (ret < 0)
|
|
goto error6;
|
|
|
|
ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
|
|
if (ret < 0)
|
|
goto error6;
|
|
}
|
|
|
|
ret = key_ref_to_ptr(key_ref)->serial;
|
|
|
|
error6:
|
|
key_ref_put(key_ref);
|
|
error5:
|
|
key_type_put(ktype);
|
|
error4:
|
|
key_ref_put(dest_ref);
|
|
error3:
|
|
key_ref_put(keyring_ref);
|
|
error2:
|
|
kfree(description);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Read a key's payload.
|
|
*
|
|
* The key must either grant the caller Read permission, or it must grant the
|
|
* caller Search permission when searched for from the process keyrings.
|
|
*
|
|
* If successful, we place up to buflen bytes of data into the buffer, if one
|
|
* is provided, and return the amount of data that is available in the key,
|
|
* irrespective of how much we copied into the buffer.
|
|
*/
|
|
long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
|
|
{
|
|
struct key *key;
|
|
key_ref_t key_ref;
|
|
long ret;
|
|
|
|
/* find the key first */
|
|
key_ref = lookup_user_key(keyid, 0, 0);
|
|
if (IS_ERR(key_ref)) {
|
|
ret = -ENOKEY;
|
|
goto error;
|
|
}
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
|
|
/* see if we can read it directly */
|
|
ret = key_permission(key_ref, KEY_READ);
|
|
if (ret == 0)
|
|
goto can_read_key;
|
|
if (ret != -EACCES)
|
|
goto error;
|
|
|
|
/* we can't; see if it's searchable from this process's keyrings
|
|
* - we automatically take account of the fact that it may be
|
|
* dangling off an instantiation key
|
|
*/
|
|
if (!is_key_possessed(key_ref)) {
|
|
ret = -EACCES;
|
|
goto error2;
|
|
}
|
|
|
|
/* the key is probably readable - now try to read it */
|
|
can_read_key:
|
|
ret = key_validate(key);
|
|
if (ret == 0) {
|
|
ret = -EOPNOTSUPP;
|
|
if (key->type->read) {
|
|
/* read the data with the semaphore held (since we
|
|
* might sleep) */
|
|
down_read(&key->sem);
|
|
ret = key->type->read(key, buffer, buflen);
|
|
up_read(&key->sem);
|
|
}
|
|
}
|
|
|
|
error2:
|
|
key_put(key);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Change the ownership of a key
|
|
*
|
|
* The key must grant the caller Setattr permission for this to work, though
|
|
* the key need not be fully instantiated yet. For the UID to be changed, or
|
|
* for the GID to be changed to a group the caller is not a member of, the
|
|
* caller must have sysadmin capability. If either uid or gid is -1 then that
|
|
* attribute is not changed.
|
|
*
|
|
* If the UID is to be changed, the new user must have sufficient quota to
|
|
* accept the key. The quota deduction will be removed from the old user to
|
|
* the new user should the attribute be changed.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
|
|
{
|
|
struct key_user *newowner, *zapowner = NULL;
|
|
struct key *key;
|
|
key_ref_t key_ref;
|
|
long ret;
|
|
kuid_t uid;
|
|
kgid_t gid;
|
|
|
|
uid = make_kuid(current_user_ns(), user);
|
|
gid = make_kgid(current_user_ns(), group);
|
|
ret = -EINVAL;
|
|
if ((user != (uid_t) -1) && !uid_valid(uid))
|
|
goto error;
|
|
if ((group != (gid_t) -1) && !gid_valid(gid))
|
|
goto error;
|
|
|
|
ret = 0;
|
|
if (user == (uid_t) -1 && group == (gid_t) -1)
|
|
goto error;
|
|
|
|
key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
|
|
KEY_SETATTR);
|
|
if (IS_ERR(key_ref)) {
|
|
ret = PTR_ERR(key_ref);
|
|
goto error;
|
|
}
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
|
|
/* make the changes with the locks held to prevent chown/chown races */
|
|
ret = -EACCES;
|
|
down_write(&key->sem);
|
|
|
|
if (!capable(CAP_SYS_ADMIN)) {
|
|
/* only the sysadmin can chown a key to some other UID */
|
|
if (user != (uid_t) -1 && !uid_eq(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 (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid))
|
|
goto error_put;
|
|
}
|
|
|
|
/* change the UID */
|
|
if (user != (uid_t) -1 && !uid_eq(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_eq(uid, GLOBAL_ROOT_UID) ?
|
|
key_quota_root_maxkeys : key_quota_maxkeys;
|
|
unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ?
|
|
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 (group != (gid_t) -1)
|
|
key->gid = gid;
|
|
|
|
ret = 0;
|
|
|
|
error_put:
|
|
up_write(&key->sem);
|
|
key_put(key);
|
|
if (zapowner)
|
|
key_user_put(zapowner);
|
|
error:
|
|
return ret;
|
|
|
|
quota_overrun:
|
|
spin_unlock(&newowner->lock);
|
|
zapowner = newowner;
|
|
ret = -EDQUOT;
|
|
goto error_put;
|
|
}
|
|
|
|
/*
|
|
* Change the permission mask on a key.
|
|
*
|
|
* The key must grant the caller Setattr permission for this to work, though
|
|
* the key need not be fully instantiated yet. If the caller does not have
|
|
* sysadmin capability, it may only change the permission on keys that it owns.
|
|
*/
|
|
long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
|
|
{
|
|
struct key *key;
|
|
key_ref_t key_ref;
|
|
long ret;
|
|
|
|
ret = -EINVAL;
|
|
if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
|
|
goto error;
|
|
|
|
key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
|
|
KEY_SETATTR);
|
|
if (IS_ERR(key_ref)) {
|
|
ret = PTR_ERR(key_ref);
|
|
goto error;
|
|
}
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
|
|
/* make the changes with the locks held to prevent chown/chmod races */
|
|
ret = -EACCES;
|
|
down_write(&key->sem);
|
|
|
|
/* if we're not the sysadmin, we can only change a key that we own */
|
|
if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) {
|
|
key->perm = perm;
|
|
ret = 0;
|
|
}
|
|
|
|
up_write(&key->sem);
|
|
key_put(key);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Get the destination keyring for instantiation and check that the caller has
|
|
* Write permission on it.
|
|
*/
|
|
static long get_instantiation_keyring(key_serial_t ringid,
|
|
struct request_key_auth *rka,
|
|
struct key **_dest_keyring)
|
|
{
|
|
key_ref_t dkref;
|
|
|
|
*_dest_keyring = NULL;
|
|
|
|
/* just return a NULL pointer if we weren't asked to make a link */
|
|
if (ringid == 0)
|
|
return 0;
|
|
|
|
/* if a specific keyring is nominated by ID, then use that */
|
|
if (ringid > 0) {
|
|
dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
|
|
if (IS_ERR(dkref))
|
|
return PTR_ERR(dkref);
|
|
*_dest_keyring = key_ref_to_ptr(dkref);
|
|
return 0;
|
|
}
|
|
|
|
if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
|
|
return -EINVAL;
|
|
|
|
/* otherwise specify the destination keyring recorded in the
|
|
* authorisation key (any KEY_SPEC_*_KEYRING) */
|
|
if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
|
|
*_dest_keyring = key_get(rka->dest_keyring);
|
|
return 0;
|
|
}
|
|
|
|
return -ENOKEY;
|
|
}
|
|
|
|
/*
|
|
* Change the request_key authorisation key on the current process.
|
|
*/
|
|
static int keyctl_change_reqkey_auth(struct key *key)
|
|
{
|
|
struct cred *new;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
key_put(new->request_key_auth);
|
|
new->request_key_auth = key_get(key);
|
|
|
|
return commit_creds(new);
|
|
}
|
|
|
|
/*
|
|
* Copy the iovec data from userspace
|
|
*/
|
|
static long copy_from_user_iovec(void *buffer, const struct iovec *iov,
|
|
unsigned ioc)
|
|
{
|
|
for (; ioc > 0; ioc--) {
|
|
if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0)
|
|
return -EFAULT;
|
|
buffer += iov->iov_len;
|
|
iov++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Instantiate a key with the specified payload and link the key into the
|
|
* destination keyring if one is given.
|
|
*
|
|
* The caller must have the appropriate instantiation permit set for this to
|
|
* work (see keyctl_assume_authority). No other permissions are required.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_instantiate_key_common(key_serial_t id,
|
|
const struct iovec *payload_iov,
|
|
unsigned ioc,
|
|
size_t plen,
|
|
key_serial_t ringid)
|
|
{
|
|
const struct cred *cred = current_cred();
|
|
struct request_key_auth *rka;
|
|
struct key *instkey, *dest_keyring;
|
|
void *payload;
|
|
long ret;
|
|
bool vm = false;
|
|
|
|
kenter("%d,,%zu,%d", id, plen, ringid);
|
|
|
|
ret = -EINVAL;
|
|
if (plen > 1024 * 1024 - 1)
|
|
goto error;
|
|
|
|
/* the appropriate instantiation authorisation key must have been
|
|
* assumed before calling this */
|
|
ret = -EPERM;
|
|
instkey = cred->request_key_auth;
|
|
if (!instkey)
|
|
goto error;
|
|
|
|
rka = instkey->payload.data;
|
|
if (rka->target_key->serial != id)
|
|
goto error;
|
|
|
|
/* pull the payload in if one was supplied */
|
|
payload = NULL;
|
|
|
|
if (payload_iov) {
|
|
ret = -ENOMEM;
|
|
payload = kmalloc(plen, GFP_KERNEL);
|
|
if (!payload) {
|
|
if (plen <= PAGE_SIZE)
|
|
goto error;
|
|
vm = true;
|
|
payload = vmalloc(plen);
|
|
if (!payload)
|
|
goto error;
|
|
}
|
|
|
|
ret = copy_from_user_iovec(payload, payload_iov, ioc);
|
|
if (ret < 0)
|
|
goto error2;
|
|
}
|
|
|
|
/* find the destination keyring amongst those belonging to the
|
|
* requesting task */
|
|
ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
|
|
if (ret < 0)
|
|
goto error2;
|
|
|
|
/* instantiate the key and link it into a keyring */
|
|
ret = key_instantiate_and_link(rka->target_key, payload, plen,
|
|
dest_keyring, instkey);
|
|
|
|
key_put(dest_keyring);
|
|
|
|
/* discard the assumed authority if it's just been disabled by
|
|
* instantiation of the key */
|
|
if (ret == 0)
|
|
keyctl_change_reqkey_auth(NULL);
|
|
|
|
error2:
|
|
if (!vm)
|
|
kfree(payload);
|
|
else
|
|
vfree(payload);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Instantiate a key with the specified payload and link the key into the
|
|
* destination keyring if one is given.
|
|
*
|
|
* The caller must have the appropriate instantiation permit set for this to
|
|
* work (see keyctl_assume_authority). No other permissions are required.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_instantiate_key(key_serial_t id,
|
|
const void __user *_payload,
|
|
size_t plen,
|
|
key_serial_t ringid)
|
|
{
|
|
if (_payload && plen) {
|
|
struct iovec iov[1] = {
|
|
[0].iov_base = (void __user *)_payload,
|
|
[0].iov_len = plen
|
|
};
|
|
|
|
return keyctl_instantiate_key_common(id, iov, 1, plen, ringid);
|
|
}
|
|
|
|
return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
|
|
}
|
|
|
|
/*
|
|
* Instantiate a key with the specified multipart payload and link the key into
|
|
* the destination keyring if one is given.
|
|
*
|
|
* The caller must have the appropriate instantiation permit set for this to
|
|
* work (see keyctl_assume_authority). No other permissions are required.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_instantiate_key_iov(key_serial_t id,
|
|
const struct iovec __user *_payload_iov,
|
|
unsigned ioc,
|
|
key_serial_t ringid)
|
|
{
|
|
struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
|
|
long ret;
|
|
|
|
if (!_payload_iov || !ioc)
|
|
goto no_payload;
|
|
|
|
ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
|
|
ARRAY_SIZE(iovstack), iovstack, &iov);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
goto no_payload_free;
|
|
|
|
ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
|
|
|
|
if (iov != iovstack)
|
|
kfree(iov);
|
|
return ret;
|
|
|
|
no_payload_free:
|
|
if (iov != iovstack)
|
|
kfree(iov);
|
|
no_payload:
|
|
return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
|
|
}
|
|
|
|
/*
|
|
* Negatively instantiate the key with the given timeout (in seconds) and link
|
|
* the key into the destination keyring if one is given.
|
|
*
|
|
* The caller must have the appropriate instantiation permit set for this to
|
|
* work (see keyctl_assume_authority). No other permissions are required.
|
|
*
|
|
* The key and any links to the key will be automatically garbage collected
|
|
* after the timeout expires.
|
|
*
|
|
* Negative keys are used to rate limit repeated request_key() calls by causing
|
|
* them to return -ENOKEY until the negative key expires.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
|
|
{
|
|
return keyctl_reject_key(id, timeout, ENOKEY, ringid);
|
|
}
|
|
|
|
/*
|
|
* Negatively instantiate the key with the given timeout (in seconds) and error
|
|
* code and link the key into the destination keyring if one is given.
|
|
*
|
|
* The caller must have the appropriate instantiation permit set for this to
|
|
* work (see keyctl_assume_authority). No other permissions are required.
|
|
*
|
|
* The key and any links to the key will be automatically garbage collected
|
|
* after the timeout expires.
|
|
*
|
|
* Negative keys are used to rate limit repeated request_key() calls by causing
|
|
* them to return the specified error code until the negative key expires.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
|
|
key_serial_t ringid)
|
|
{
|
|
const struct cred *cred = current_cred();
|
|
struct request_key_auth *rka;
|
|
struct key *instkey, *dest_keyring;
|
|
long ret;
|
|
|
|
kenter("%d,%u,%u,%d", id, timeout, error, ringid);
|
|
|
|
/* must be a valid error code and mustn't be a kernel special */
|
|
if (error <= 0 ||
|
|
error >= MAX_ERRNO ||
|
|
error == ERESTARTSYS ||
|
|
error == ERESTARTNOINTR ||
|
|
error == ERESTARTNOHAND ||
|
|
error == ERESTART_RESTARTBLOCK)
|
|
return -EINVAL;
|
|
|
|
/* the appropriate instantiation authorisation key must have been
|
|
* assumed before calling this */
|
|
ret = -EPERM;
|
|
instkey = cred->request_key_auth;
|
|
if (!instkey)
|
|
goto error;
|
|
|
|
rka = instkey->payload.data;
|
|
if (rka->target_key->serial != id)
|
|
goto error;
|
|
|
|
/* find the destination keyring if present (which must also be
|
|
* writable) */
|
|
ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
/* instantiate the key and link it into a keyring */
|
|
ret = key_reject_and_link(rka->target_key, timeout, error,
|
|
dest_keyring, instkey);
|
|
|
|
key_put(dest_keyring);
|
|
|
|
/* discard the assumed authority if it's just been disabled by
|
|
* instantiation of the key */
|
|
if (ret == 0)
|
|
keyctl_change_reqkey_auth(NULL);
|
|
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Read or set the default keyring in which request_key() will cache keys and
|
|
* return the old setting.
|
|
*
|
|
* If a process keyring is specified then this will be created if it doesn't
|
|
* yet exist. The old setting will be returned if successful.
|
|
*/
|
|
long keyctl_set_reqkey_keyring(int reqkey_defl)
|
|
{
|
|
struct cred *new;
|
|
int ret, old_setting;
|
|
|
|
old_setting = current_cred_xxx(jit_keyring);
|
|
|
|
if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
|
|
return old_setting;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
switch (reqkey_defl) {
|
|
case KEY_REQKEY_DEFL_THREAD_KEYRING:
|
|
ret = install_thread_keyring_to_cred(new);
|
|
if (ret < 0)
|
|
goto error;
|
|
goto set;
|
|
|
|
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
|
|
ret = install_process_keyring_to_cred(new);
|
|
if (ret < 0) {
|
|
if (ret != -EEXIST)
|
|
goto error;
|
|
ret = 0;
|
|
}
|
|
goto set;
|
|
|
|
case KEY_REQKEY_DEFL_DEFAULT:
|
|
case KEY_REQKEY_DEFL_SESSION_KEYRING:
|
|
case KEY_REQKEY_DEFL_USER_KEYRING:
|
|
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
|
|
case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
|
|
goto set;
|
|
|
|
case KEY_REQKEY_DEFL_NO_CHANGE:
|
|
case KEY_REQKEY_DEFL_GROUP_KEYRING:
|
|
default:
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
set:
|
|
new->jit_keyring = reqkey_defl;
|
|
commit_creds(new);
|
|
return old_setting;
|
|
error:
|
|
abort_creds(new);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Set or clear the timeout on a key.
|
|
*
|
|
* Either the key must grant the caller Setattr permission or else the caller
|
|
* must hold an instantiation authorisation token for the key.
|
|
*
|
|
* The timeout is either 0 to clear the timeout, or a number of seconds from
|
|
* the current time. The key and any links to the key will be automatically
|
|
* garbage collected after the timeout expires.
|
|
*
|
|
* If successful, 0 is returned.
|
|
*/
|
|
long keyctl_set_timeout(key_serial_t id, unsigned timeout)
|
|
{
|
|
struct key *key, *instkey;
|
|
key_ref_t key_ref;
|
|
long ret;
|
|
|
|
key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
|
|
KEY_SETATTR);
|
|
if (IS_ERR(key_ref)) {
|
|
/* setting the timeout on a key under construction is permitted
|
|
* if we have the authorisation token handy */
|
|
if (PTR_ERR(key_ref) == -EACCES) {
|
|
instkey = key_get_instantiation_authkey(id);
|
|
if (!IS_ERR(instkey)) {
|
|
key_put(instkey);
|
|
key_ref = lookup_user_key(id,
|
|
KEY_LOOKUP_PARTIAL,
|
|
0);
|
|
if (!IS_ERR(key_ref))
|
|
goto okay;
|
|
}
|
|
}
|
|
|
|
ret = PTR_ERR(key_ref);
|
|
goto error;
|
|
}
|
|
|
|
okay:
|
|
key = key_ref_to_ptr(key_ref);
|
|
key_set_timeout(key, timeout);
|
|
key_put(key);
|
|
|
|
ret = 0;
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Assume (or clear) the authority to instantiate the specified key.
|
|
*
|
|
* This sets the authoritative token currently in force for key instantiation.
|
|
* This must be done for a key to be instantiated. It has the effect of making
|
|
* available all the keys from the caller of the request_key() that created a
|
|
* key to request_key() calls made by the caller of this function.
|
|
*
|
|
* The caller must have the instantiation key in their process keyrings with a
|
|
* Search permission grant available to the caller.
|
|
*
|
|
* If the ID given is 0, then the setting will be cleared and 0 returned.
|
|
*
|
|
* If the ID given has a matching an authorisation key, then that key will be
|
|
* set and its ID will be returned. The authorisation key can be read to get
|
|
* the callout information passed to request_key().
|
|
*/
|
|
long keyctl_assume_authority(key_serial_t id)
|
|
{
|
|
struct key *authkey;
|
|
long ret;
|
|
|
|
/* special key IDs aren't permitted */
|
|
ret = -EINVAL;
|
|
if (id < 0)
|
|
goto error;
|
|
|
|
/* we divest ourselves of authority if given an ID of 0 */
|
|
if (id == 0) {
|
|
ret = keyctl_change_reqkey_auth(NULL);
|
|
goto error;
|
|
}
|
|
|
|
/* attempt to assume the authority temporarily granted to us whilst we
|
|
* instantiate the specified key
|
|
* - the authorisation key must be in the current task's keyrings
|
|
* somewhere
|
|
*/
|
|
authkey = key_get_instantiation_authkey(id);
|
|
if (IS_ERR(authkey)) {
|
|
ret = PTR_ERR(authkey);
|
|
goto error;
|
|
}
|
|
|
|
ret = keyctl_change_reqkey_auth(authkey);
|
|
if (ret < 0)
|
|
goto error;
|
|
key_put(authkey);
|
|
|
|
ret = authkey->serial;
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Get a key's the LSM security label.
|
|
*
|
|
* The key must grant the caller View permission for this to work.
|
|
*
|
|
* If there's a buffer, then up to buflen bytes of data will be placed into it.
|
|
*
|
|
* If successful, the amount of information available will be returned,
|
|
* irrespective of how much was copied (including the terminal NUL).
|
|
*/
|
|
long keyctl_get_security(key_serial_t keyid,
|
|
char __user *buffer,
|
|
size_t buflen)
|
|
{
|
|
struct key *key, *instkey;
|
|
key_ref_t key_ref;
|
|
char *context;
|
|
long ret;
|
|
|
|
key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
|
|
if (IS_ERR(key_ref)) {
|
|
if (PTR_ERR(key_ref) != -EACCES)
|
|
return PTR_ERR(key_ref);
|
|
|
|
/* viewing a key under construction is also permitted if we
|
|
* have the authorisation token handy */
|
|
instkey = key_get_instantiation_authkey(keyid);
|
|
if (IS_ERR(instkey))
|
|
return PTR_ERR(instkey);
|
|
key_put(instkey);
|
|
|
|
key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
|
|
if (IS_ERR(key_ref))
|
|
return PTR_ERR(key_ref);
|
|
}
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
ret = security_key_getsecurity(key, &context);
|
|
if (ret == 0) {
|
|
/* if no information was returned, give userspace an empty
|
|
* string */
|
|
ret = 1;
|
|
if (buffer && buflen > 0 &&
|
|
copy_to_user(buffer, "", 1) != 0)
|
|
ret = -EFAULT;
|
|
} else if (ret > 0) {
|
|
/* return as much data as there's room for */
|
|
if (buffer && buflen > 0) {
|
|
if (buflen > ret)
|
|
buflen = ret;
|
|
|
|
if (copy_to_user(buffer, context, buflen) != 0)
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
kfree(context);
|
|
}
|
|
|
|
key_ref_put(key_ref);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Attempt to install the calling process's session keyring on the process's
|
|
* parent process.
|
|
*
|
|
* The keyring must exist and must grant the caller LINK permission, and the
|
|
* parent process must be single-threaded and must have the same effective
|
|
* ownership as this process and mustn't be SUID/SGID.
|
|
*
|
|
* The keyring will be emplaced on the parent when it next resumes userspace.
|
|
*
|
|
* If successful, 0 will be returned.
|
|
*/
|
|
long keyctl_session_to_parent(void)
|
|
{
|
|
struct task_struct *me, *parent;
|
|
const struct cred *mycred, *pcred;
|
|
struct callback_head *newwork, *oldwork;
|
|
key_ref_t keyring_r;
|
|
struct cred *cred;
|
|
int ret;
|
|
|
|
keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
|
|
if (IS_ERR(keyring_r))
|
|
return PTR_ERR(keyring_r);
|
|
|
|
ret = -ENOMEM;
|
|
|
|
/* our parent is going to need a new cred struct, a new tgcred struct
|
|
* and new security data, so we allocate them here to prevent ENOMEM in
|
|
* our parent */
|
|
cred = cred_alloc_blank();
|
|
if (!cred)
|
|
goto error_keyring;
|
|
newwork = &cred->rcu;
|
|
|
|
cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
|
|
init_task_work(newwork, key_change_session_keyring);
|
|
|
|
me = current;
|
|
rcu_read_lock();
|
|
write_lock_irq(&tasklist_lock);
|
|
|
|
ret = -EPERM;
|
|
oldwork = NULL;
|
|
parent = me->real_parent;
|
|
|
|
/* the parent mustn't be init and mustn't be a kernel thread */
|
|
if (parent->pid <= 1 || !parent->mm)
|
|
goto unlock;
|
|
|
|
/* the parent must be single threaded */
|
|
if (!thread_group_empty(parent))
|
|
goto unlock;
|
|
|
|
/* the parent and the child must have different session keyrings or
|
|
* there's no point */
|
|
mycred = current_cred();
|
|
pcred = __task_cred(parent);
|
|
if (mycred == pcred ||
|
|
mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) {
|
|
ret = 0;
|
|
goto unlock;
|
|
}
|
|
|
|
/* the parent must have the same effective ownership and mustn't be
|
|
* SUID/SGID */
|
|
if (!uid_eq(pcred->uid, mycred->euid) ||
|
|
!uid_eq(pcred->euid, mycred->euid) ||
|
|
!uid_eq(pcred->suid, mycred->euid) ||
|
|
!gid_eq(pcred->gid, mycred->egid) ||
|
|
!gid_eq(pcred->egid, mycred->egid) ||
|
|
!gid_eq(pcred->sgid, mycred->egid))
|
|
goto unlock;
|
|
|
|
/* the keyrings must have the same UID */
|
|
if ((pcred->tgcred->session_keyring &&
|
|
!uid_eq(pcred->tgcred->session_keyring->uid, mycred->euid)) ||
|
|
!uid_eq(mycred->tgcred->session_keyring->uid, mycred->euid))
|
|
goto unlock;
|
|
|
|
/* cancel an already pending keyring replacement */
|
|
oldwork = task_work_cancel(parent, key_change_session_keyring);
|
|
|
|
/* the replacement session keyring is applied just prior to userspace
|
|
* restarting */
|
|
ret = task_work_add(parent, newwork, true);
|
|
if (!ret)
|
|
newwork = NULL;
|
|
unlock:
|
|
write_unlock_irq(&tasklist_lock);
|
|
rcu_read_unlock();
|
|
if (oldwork)
|
|
put_cred(container_of(oldwork, struct cred, rcu));
|
|
if (newwork)
|
|
put_cred(cred);
|
|
return ret;
|
|
|
|
error_keyring:
|
|
key_ref_put(keyring_r);
|
|
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);
|
|
|
|
case KEYCTL_SESSION_TO_PARENT:
|
|
return keyctl_session_to_parent();
|
|
|
|
case KEYCTL_REJECT:
|
|
return keyctl_reject_key((key_serial_t) arg2,
|
|
(unsigned) arg3,
|
|
(unsigned) arg4,
|
|
(key_serial_t) arg5);
|
|
|
|
case KEYCTL_INSTANTIATE_IOV:
|
|
return keyctl_instantiate_key_iov(
|
|
(key_serial_t) arg2,
|
|
(const struct iovec __user *) arg3,
|
|
(unsigned) arg4,
|
|
(key_serial_t) arg5);
|
|
|
|
case KEYCTL_INVALIDATE:
|
|
return keyctl_invalidate_key((key_serial_t) arg2);
|
|
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|