Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 114f740..957b9e3 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -1,48 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* Request a key from userspace
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
* See Documentation/security/keys/request-key.rst
*/
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/sched.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/keyctl.h>
#include <linux/slab.h>
+#include <net/net_namespace.h>
#include "internal.h"
+#include <keys/request_key_auth-type.h>
#define key_negative_timeout 60 /* default timeout on a negative key's existence */
+static struct key *check_cached_key(struct keyring_search_context *ctx)
+{
+#ifdef CONFIG_KEYS_REQUEST_CACHE
+ struct key *key = current->cached_requested_key;
+
+ if (key &&
+ ctx->match_data.cmp(key, &ctx->match_data) &&
+ !(key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED))))
+ return key_get(key);
+#endif
+ return NULL;
+}
+
+static void cache_requested_key(struct key *key)
+{
+#ifdef CONFIG_KEYS_REQUEST_CACHE
+ struct task_struct *t = current;
+
+ key_put(t->cached_requested_key);
+ t->cached_requested_key = key_get(key);
+ set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+#endif
+}
+
/**
* complete_request_key - Complete the construction of a key.
- * @cons: The key construction record.
+ * @authkey: The authorisation key.
* @error: The success or failute of the construction.
*
* Complete the attempt to construct a key. The key will be negated
* if an error is indicated. The authorisation key will be revoked
* unconditionally.
*/
-void complete_request_key(struct key_construction *cons, int error)
+void complete_request_key(struct key *authkey, int error)
{
- kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
+ struct request_key_auth *rka = get_request_key_auth(authkey);
+ struct key *key = rka->target_key;
+
+ kenter("%d{%d},%d", authkey->serial, key->serial, error);
if (error < 0)
- key_negate_and_link(cons->key, key_negative_timeout, NULL,
- cons->authkey);
+ key_negate_and_link(key, key_negative_timeout, NULL, authkey);
else
- key_revoke(cons->authkey);
-
- key_put(cons->key);
- key_put(cons->authkey);
- kfree(cons);
+ key_revoke(authkey);
}
EXPORT_SYMBOL(complete_request_key);
@@ -91,25 +112,23 @@
* Request userspace finish the construction of a key
* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
*/
-static int call_sbin_request_key(struct key_construction *cons,
- const char *op,
- void *aux)
+static int call_sbin_request_key(struct key *authkey, void *aux)
{
static char const request_key[] = "/sbin/request-key";
+ struct request_key_auth *rka = get_request_key_auth(authkey);
const struct cred *cred = current_cred();
key_serial_t prkey, sskey;
- struct key *key = cons->key, *authkey = cons->authkey, *keyring,
- *session;
+ struct key *key = rka->target_key, *keyring, *session, *user_session;
char *argv[9], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
char desc[20];
int ret, i;
- kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
+ kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op);
- ret = install_user_keyrings();
+ ret = look_up_user_keyrings(NULL, &user_session);
if (ret < 0)
- goto error_alloc;
+ goto error_us;
/* allocate a new session keyring */
sprintf(desc, "_req.%u", key->serial);
@@ -145,12 +164,10 @@
prkey = cred->process_keyring->serial;
sprintf(keyring_str[1], "%d", prkey);
- rcu_read_lock();
- session = rcu_dereference(cred->session_keyring);
+ session = cred->session_keyring;
if (!session)
- session = cred->user->session_keyring;
+ session = user_session;
sskey = session->serial;
- rcu_read_unlock();
sprintf(keyring_str[2], "%d", sskey);
@@ -163,7 +180,7 @@
/* set up the argument list */
i = 0;
argv[i++] = (char *)request_key;
- argv[i++] = (char *) op;
+ argv[i++] = (char *)rka->op;
argv[i++] = key_str;
argv[i++] = uid_str;
argv[i++] = gid_str;
@@ -191,7 +208,9 @@
key_put(keyring);
error_alloc:
- complete_request_key(cons, ret);
+ key_put(user_session);
+error_us:
+ complete_request_key(authkey, ret);
kleave(" = %d", ret);
return ret;
}
@@ -205,42 +224,31 @@
size_t callout_len, void *aux,
struct key *dest_keyring)
{
- struct key_construction *cons;
request_key_actor_t actor;
struct key *authkey;
int ret;
kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
- cons = kmalloc(sizeof(*cons), GFP_KERNEL);
- if (!cons)
- return -ENOMEM;
-
/* allocate an authorisation key */
- authkey = request_key_auth_new(key, callout_info, callout_len,
+ authkey = request_key_auth_new(key, "create", callout_info, callout_len,
dest_keyring);
- if (IS_ERR(authkey)) {
- kfree(cons);
- ret = PTR_ERR(authkey);
- authkey = NULL;
- } else {
- cons->authkey = key_get(authkey);
- cons->key = key_get(key);
+ if (IS_ERR(authkey))
+ return PTR_ERR(authkey);
- /* make the call */
- actor = call_sbin_request_key;
- if (key->type->request_key)
- actor = key->type->request_key;
+ /* Make the call */
+ actor = call_sbin_request_key;
+ if (key->type->request_key)
+ actor = key->type->request_key;
- ret = actor(cons, "create", aux);
+ ret = actor(authkey, aux);
- /* check that the actor called complete_request_key() prior to
- * returning an error */
- WARN_ON(ret < 0 &&
- !test_bit(KEY_FLAG_REVOKED, &authkey->flags));
- key_put(authkey);
- }
+ /* check that the actor called complete_request_key() prior to
+ * returning an error */
+ WARN_ON(ret < 0 &&
+ !test_bit(KEY_FLAG_INVALIDATED, &authkey->flags));
+ key_put(authkey);
kleave(" = %d", ret);
return ret;
}
@@ -275,7 +283,7 @@
if (cred->request_key_auth) {
authkey = cred->request_key_auth;
down_read(&authkey->sem);
- rka = authkey->payload.data[0];
+ rka = get_request_key_auth(authkey);
if (!test_bit(KEY_FLAG_REVOKED,
&authkey->flags))
dest_keyring =
@@ -287,32 +295,36 @@
}
}
+ /* fall through */
case KEY_REQKEY_DEFL_THREAD_KEYRING:
dest_keyring = key_get(cred->thread_keyring);
if (dest_keyring)
break;
+ /* fall through */
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
dest_keyring = key_get(cred->process_keyring);
if (dest_keyring)
break;
+ /* fall through */
case KEY_REQKEY_DEFL_SESSION_KEYRING:
- rcu_read_lock();
- dest_keyring = key_get(
- rcu_dereference(cred->session_keyring));
- rcu_read_unlock();
+ dest_keyring = key_get(cred->session_keyring);
if (dest_keyring)
break;
+ /* fall through */
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
- dest_keyring =
- key_get(cred->user->session_keyring);
+ ret = look_up_user_keyrings(NULL, &dest_keyring);
+ if (ret < 0)
+ return ret;
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
- dest_keyring = key_get(cred->user->uid_keyring);
+ ret = look_up_user_keyrings(&dest_keyring, NULL);
+ if (ret < 0)
+ return ret;
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
@@ -357,7 +369,7 @@
struct key_user *user,
struct key **_key)
{
- struct assoc_array_edit *edit;
+ struct assoc_array_edit *edit = NULL;
struct key *key;
key_perm_t perm;
key_ref_t key_ref;
@@ -386,6 +398,9 @@
set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
if (dest_keyring) {
+ ret = __key_link_lock(dest_keyring, &ctx->index_key);
+ if (ret < 0)
+ goto link_lock_failed;
ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit);
if (ret < 0)
goto link_prealloc_failed;
@@ -396,7 +411,9 @@
* waited for locks */
mutex_lock(&key_construction_mutex);
- key_ref = search_process_keyrings(ctx);
+ rcu_read_lock();
+ key_ref = search_process_keyrings_rcu(ctx);
+ rcu_read_unlock();
if (!IS_ERR(key_ref))
goto key_already_present;
@@ -437,6 +454,8 @@
return ret;
link_prealloc_failed:
+ __key_link_end(dest_keyring, &ctx->index_key, edit);
+link_lock_failed:
mutex_unlock(&user->cons_lock);
key_put(key);
kleave(" = %d [prelink]", ret);
@@ -511,16 +530,18 @@
* request_key_and_link - Request a key and cache it in a keyring.
* @type: The type of key we want.
* @description: The searchable description of the key.
+ * @domain_tag: The domain in which the key operates.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
* @dest_keyring: Where to cache the key.
* @flags: Flags to key_alloc().
*
- * A key matching the specified criteria is searched for in the process's
- * keyrings and returned with its usage count incremented if found. Otherwise,
- * if callout_info is not NULL, a key will be allocated and some service
- * (probably in userspace) will be asked to instantiate it.
+ * A key matching the specified criteria (type, description, domain_tag) is
+ * searched for in the process's keyrings and returned with its usage count
+ * incremented if found. Otherwise, if callout_info is not NULL, a key will be
+ * allocated and some service (probably in userspace) will be asked to
+ * instantiate it.
*
* If successfully found or created, the key will be linked to the destination
* keyring if one is provided.
@@ -536,6 +557,7 @@
*/
struct key *request_key_and_link(struct key_type *type,
const char *description,
+ struct key_tag *domain_tag,
const void *callout_info,
size_t callout_len,
void *aux,
@@ -544,13 +566,16 @@
{
struct keyring_search_context ctx = {
.index_key.type = type,
+ .index_key.domain_tag = domain_tag,
.index_key.description = description,
+ .index_key.desc_len = strlen(description),
.cred = current_cred(),
.match_data.cmp = key_default_cmp,
.match_data.raw_data = description,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
.flags = (KEYRING_SEARCH_DO_STATE_CHECK |
- KEYRING_SEARCH_SKIP_EXPIRED),
+ KEYRING_SEARCH_SKIP_EXPIRED |
+ KEYRING_SEARCH_RECURSE),
};
struct key *key;
key_ref_t key_ref;
@@ -568,10 +593,26 @@
}
}
+ key = check_cached_key(&ctx);
+ if (key)
+ goto error_free;
+
/* search all the process keyrings for a key */
- key_ref = search_process_keyrings(&ctx);
+ rcu_read_lock();
+ key_ref = search_process_keyrings_rcu(&ctx);
+ rcu_read_unlock();
if (!IS_ERR(key_ref)) {
+ if (dest_keyring) {
+ ret = key_task_permission(key_ref, current_cred(),
+ KEY_NEED_LINK);
+ if (ret < 0) {
+ key_ref_put(key_ref);
+ key = ERR_PTR(ret);
+ goto error_free;
+ }
+ }
+
key = key_ref_to_ptr(key_ref);
if (dest_keyring) {
ret = key_link(dest_keyring, key);
@@ -581,6 +622,9 @@
goto error_free;
}
}
+
+ /* Only cache the key on immediate success */
+ cache_requested_key(key);
} else if (PTR_ERR(key_ref) != -EAGAIN) {
key = ERR_CAST(key_ref);
} else {
@@ -629,9 +673,10 @@
EXPORT_SYMBOL(wait_for_key_construction);
/**
- * request_key - Request a key and wait for construction
+ * request_key_tag - Request a key and wait for construction
* @type: Type of key.
* @description: The searchable description of the key.
+ * @domain_tag: The domain in which the key operates.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
*
* As for request_key_and_link() except that it does not add the returned key
@@ -642,9 +687,10 @@
* Furthermore, it then works as wait_for_key_construction() to wait for the
* completion of keys undergoing construction with a non-interruptible wait.
*/
-struct key *request_key(struct key_type *type,
- const char *description,
- const char *callout_info)
+struct key *request_key_tag(struct key_type *type,
+ const char *description,
+ struct key_tag *domain_tag,
+ const char *callout_info)
{
struct key *key;
size_t callout_len = 0;
@@ -652,7 +698,8 @@
if (callout_info)
callout_len = strlen(callout_info);
- key = request_key_and_link(type, description, callout_info, callout_len,
+ key = request_key_and_link(type, description, domain_tag,
+ callout_info, callout_len,
NULL, NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key)) {
ret = wait_for_key_construction(key, false);
@@ -663,12 +710,13 @@
}
return key;
}
-EXPORT_SYMBOL(request_key);
+EXPORT_SYMBOL(request_key_tag);
/**
* request_key_with_auxdata - Request a key with auxiliary data for the upcaller
* @type: The type of key we want.
* @description: The searchable description of the key.
+ * @domain_tag: The domain in which the key operates.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
@@ -681,6 +729,7 @@
*/
struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
+ struct key_tag *domain_tag,
const void *callout_info,
size_t callout_len,
void *aux)
@@ -688,7 +737,8 @@
struct key *key;
int ret;
- key = request_key_and_link(type, description, callout_info, callout_len,
+ key = request_key_and_link(type, description, domain_tag,
+ callout_info, callout_len,
aux, NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key)) {
ret = wait_for_key_construction(key, false);
@@ -701,52 +751,55 @@
}
EXPORT_SYMBOL(request_key_with_auxdata);
-/*
- * request_key_async - Request a key (allow async construction)
- * @type: Type of key.
- * @description: The searchable description of the key.
- * @callout_info: The data to pass to the instantiation upcall (or NULL).
- * @callout_len: The length of callout_info.
+/**
+ * request_key_rcu - Request key from RCU-read-locked context
+ * @type: The type of key we want.
+ * @description: The name of the key we want.
+ * @domain_tag: The domain in which the key operates.
*
- * As for request_key_and_link() except that it does not add the returned key
- * to a keyring if found, new keys are always allocated in the user's quota and
- * no auxiliary data can be passed.
+ * Request a key from a context that we may not sleep in (such as RCU-mode
+ * pathwalk). Keys under construction are ignored.
*
- * The caller should call wait_for_key_construction() to wait for the
- * completion of the returned key if it is still undergoing construction.
+ * Return a pointer to the found key if successful, -ENOKEY if we couldn't find
+ * a key or some other error if the key found was unsuitable or inaccessible.
*/
-struct key *request_key_async(struct key_type *type,
- const char *description,
- const void *callout_info,
- size_t callout_len)
+struct key *request_key_rcu(struct key_type *type,
+ const char *description,
+ struct key_tag *domain_tag)
{
- return request_key_and_link(type, description, callout_info,
- callout_len, NULL, NULL,
- KEY_ALLOC_IN_QUOTA);
-}
-EXPORT_SYMBOL(request_key_async);
+ struct keyring_search_context ctx = {
+ .index_key.type = type,
+ .index_key.domain_tag = domain_tag,
+ .index_key.description = description,
+ .index_key.desc_len = strlen(description),
+ .cred = current_cred(),
+ .match_data.cmp = key_default_cmp,
+ .match_data.raw_data = description,
+ .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+ .flags = (KEYRING_SEARCH_DO_STATE_CHECK |
+ KEYRING_SEARCH_SKIP_EXPIRED),
+ };
+ struct key *key;
+ key_ref_t key_ref;
-/*
- * request a key with auxiliary data for the upcaller (allow async construction)
- * @type: Type of key.
- * @description: The searchable description of the key.
- * @callout_info: The data to pass to the instantiation upcall (or NULL).
- * @callout_len: The length of callout_info.
- * @aux: Auxiliary data for the upcall.
- *
- * As for request_key_and_link() except that it does not add the returned key
- * to a keyring if found and new keys are always allocated in the user's quota.
- *
- * The caller should call wait_for_key_construction() to wait for the
- * completion of the returned key if it is still undergoing construction.
- */
-struct key *request_key_async_with_auxdata(struct key_type *type,
- const char *description,
- const void *callout_info,
- size_t callout_len,
- void *aux)
-{
- return request_key_and_link(type, description, callout_info,
- callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA);
+ kenter("%s,%s", type->name, description);
+
+ key = check_cached_key(&ctx);
+ if (key)
+ return key;
+
+ /* search all the process keyrings for a key */
+ key_ref = search_process_keyrings_rcu(&ctx);
+ if (IS_ERR(key_ref)) {
+ key = ERR_CAST(key_ref);
+ if (PTR_ERR(key_ref) == -EAGAIN)
+ key = ERR_PTR(-ENOKEY);
+ } else {
+ key = key_ref_to_ptr(key_ref);
+ cache_requested_key(key);
+ }
+
+ kleave(" = %p", key);
+ return key;
}
-EXPORT_SYMBOL(request_key_async_with_auxdata);
+EXPORT_SYMBOL(request_key_rcu);