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Diffstat (limited to 'security/keys/request_key.c')
-rw-r--r--security/keys/request_key.c221
1 files changed, 168 insertions, 53 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 9705b1aeba5..dfcd983af1f 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -1,6 +1,6 @@
/* request_key.c: request a key from userspace
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -13,6 +13,7 @@
#include <linux/sched.h>
#include <linux/kmod.h>
#include <linux/err.h>
+#include <linux/keyctl.h>
#include "internal.h"
struct key_construction {
@@ -27,18 +28,26 @@ DECLARE_WAIT_QUEUE_HEAD(request_key_conswq);
/*
* request userspace finish the construction of a key
* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring> <info>"
- * - if callout_info is an empty string, it'll be rendered as a "-" instead
*/
static int call_request_key(struct key *key,
const char *op,
const char *callout_info)
{
struct task_struct *tsk = current;
- unsigned long flags;
key_serial_t prkey, sskey;
+ struct key *session_keyring, *rkakey;
char *argv[10], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
- int i;
+ int ret, i;
+
+ kenter("{%d},%s,%s", key->serial, op, callout_info);
+
+ /* generate a new session keyring with an auth key in it */
+ session_keyring = request_key_auth_new(key, &rkakey);
+ if (IS_ERR(session_keyring)) {
+ ret = PTR_ERR(session_keyring);
+ goto error;
+ }
/* record the UID and GID */
sprintf(uid_str, "%d", current->fsuid);
@@ -55,17 +64,17 @@ static int call_request_key(struct key *key,
if (tsk->signal->process_keyring)
prkey = tsk->signal->process_keyring->serial;
- sskey = 0;
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- if (tsk->signal->session_keyring)
- sskey = tsk->signal->session_keyring->serial;
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-
+ sprintf(keyring_str[1], "%d", prkey);
- if (!sskey)
+ if (tsk->signal->session_keyring) {
+ rcu_read_lock();
+ sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
+ rcu_read_unlock();
+ }
+ else {
sskey = tsk->user->session_keyring->serial;
+ }
- sprintf(keyring_str[1], "%d", prkey);
sprintf(keyring_str[2], "%d", sskey);
/* set up a minimal environment */
@@ -84,11 +93,20 @@ static int call_request_key(struct key *key,
argv[i++] = keyring_str[0];
argv[i++] = keyring_str[1];
argv[i++] = keyring_str[2];
- argv[i++] = callout_info[0] ? (char *) callout_info : "-";
+ argv[i++] = (char *) callout_info;
argv[i] = NULL;
/* do it */
- return call_usermodehelper(argv[0], argv, envp, 1);
+ ret = call_usermodehelper_keys(argv[0], argv, envp, session_keyring, 1);
+
+ /* dispose of the special keys */
+ key_revoke(rkakey);
+ key_put(rkakey);
+ key_put(session_keyring);
+
+ error:
+ kleave(" = %d", ret);
+ return ret;
} /* end call_request_key() */
@@ -105,7 +123,9 @@ static struct key *__request_key_construction(struct key_type *type,
struct key_construction cons;
struct timespec now;
struct key *key;
- int ret, negative;
+ int ret, negated;
+
+ kenter("%s,%s,%s", type->name, description, callout_info);
/* create a key and add it to the queue */
key = key_alloc(type, description,
@@ -113,9 +133,7 @@ static struct key *__request_key_construction(struct key_type *type,
if (IS_ERR(key))
goto alloc_failed;
- write_lock(&key->lock);
- key->flags |= KEY_FLAG_USER_CONSTRUCT;
- write_unlock(&key->lock);
+ set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
cons.key = key;
list_add_tail(&cons.link, &key->user->consq);
@@ -130,7 +148,7 @@ static struct key *__request_key_construction(struct key_type *type,
/* if the key wasn't instantiated, then we want to give an error */
ret = -ENOKEY;
- if (!(key->flags & KEY_FLAG_INSTANTIATED))
+ if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
goto request_failed;
down_write(&key_construction_sem);
@@ -139,12 +157,13 @@ static struct key *__request_key_construction(struct key_type *type,
/* also give an error if the key was negatively instantiated */
check_not_negative:
- if (key->flags & KEY_FLAG_NEGATIVE) {
+ if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
key_put(key);
key = ERR_PTR(-ENOKEY);
}
out:
+ kleave(" = %p", key);
return key;
request_failed:
@@ -152,24 +171,23 @@ static struct key *__request_key_construction(struct key_type *type,
* - remove from construction queue
* - mark the key as dead
*/
- negative = 0;
+ negated = 0;
down_write(&key_construction_sem);
list_del(&cons.link);
- write_lock(&key->lock);
- key->flags &= ~KEY_FLAG_USER_CONSTRUCT;
-
/* check it didn't get instantiated between the check and the down */
- if (!(key->flags & KEY_FLAG_INSTANTIATED)) {
- key->flags |= KEY_FLAG_INSTANTIATED | KEY_FLAG_NEGATIVE;
- negative = 1;
+ if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
+ set_bit(KEY_FLAG_NEGATIVE, &key->flags);
+ set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
+ negated = 1;
}
- write_unlock(&key->lock);
+ clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
+
up_write(&key_construction_sem);
- if (!negative)
+ if (!negated)
goto check_not_negative; /* surprisingly, the key got
* instantiated */
@@ -178,13 +196,12 @@ static struct key *__request_key_construction(struct key_type *type,
key->expiry = now.tv_sec + key_negative_timeout;
if (current->signal->session_keyring) {
- unsigned long flags;
struct key *keyring;
- spin_lock_irqsave(&current->sighand->siglock, flags);
- keyring = current->signal->session_keyring;
+ rcu_read_lock();
+ keyring = rcu_dereference(current->signal->session_keyring);
atomic_inc(&keyring->usage);
- spin_unlock_irqrestore(&current->sighand->siglock, flags);
+ rcu_read_unlock();
key_link(keyring, key);
key_put(keyring);
@@ -220,6 +237,9 @@ static struct key *request_key_construction(struct key_type *type,
DECLARE_WAITQUEUE(myself, current);
+ kenter("%s,%s,{%d},%s",
+ type->name, description, user->uid, callout_info);
+
/* see if there's such a key under construction already */
down_write(&key_construction_sem);
@@ -236,6 +256,7 @@ static struct key *request_key_construction(struct key_type *type,
/* see about getting userspace to construct the key */
key = __request_key_construction(type, description, callout_info);
error:
+ kleave(" = %p", key);
return key;
/* someone else has the same key under construction
@@ -249,8 +270,10 @@ static struct key *request_key_construction(struct key_type *type,
add_wait_queue(&request_key_conswq, &myself);
for (;;) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- if (!(ckey->flags & KEY_FLAG_USER_CONSTRUCT))
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!test_bit(KEY_FLAG_USER_CONSTRUCT, &ckey->flags))
+ break;
+ if (signal_pending(current))
break;
schedule();
}
@@ -271,21 +294,83 @@ static struct key *request_key_construction(struct key_type *type,
/*****************************************************************************/
/*
+ * link a freshly minted key to an appropriate destination keyring
+ */
+static void request_key_link(struct key *key, struct key *dest_keyring)
+{
+ struct task_struct *tsk = current;
+ struct key *drop = NULL;
+
+ kenter("{%d},%p", key->serial, dest_keyring);
+
+ /* find the appropriate keyring */
+ if (!dest_keyring) {
+ switch (tsk->jit_keyring) {
+ case KEY_REQKEY_DEFL_DEFAULT:
+ case KEY_REQKEY_DEFL_THREAD_KEYRING:
+ dest_keyring = tsk->thread_keyring;
+ if (dest_keyring)
+ break;
+
+ case KEY_REQKEY_DEFL_PROCESS_KEYRING:
+ dest_keyring = tsk->signal->process_keyring;
+ if (dest_keyring)
+ break;
+
+ case KEY_REQKEY_DEFL_SESSION_KEYRING:
+ rcu_read_lock();
+ dest_keyring = key_get(
+ rcu_dereference(tsk->signal->session_keyring));
+ rcu_read_unlock();
+ drop = dest_keyring;
+
+ if (dest_keyring)
+ break;
+
+ case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
+ dest_keyring = current->user->session_keyring;
+ break;
+
+ case KEY_REQKEY_DEFL_USER_KEYRING:
+ dest_keyring = current->user->uid_keyring;
+ break;
+
+ case KEY_REQKEY_DEFL_GROUP_KEYRING:
+ default:
+ BUG();
+ }
+ }
+
+ /* and attach the key to it */
+ key_link(dest_keyring, key);
+
+ key_put(drop);
+
+ kleave("");
+
+} /* end request_key_link() */
+
+/*****************************************************************************/
+/*
* request a key
* - search the process's keyrings
* - check the list of keys being created or updated
- * - call out to userspace for a key if requested (supplementary info can be
- * passed)
+ * - call out to userspace for a key if supplementary info was provided
+ * - cache the key in an appropriate keyring
*/
-struct key *request_key(struct key_type *type,
- const char *description,
- const char *callout_info)
+struct key *request_key_and_link(struct key_type *type,
+ const char *description,
+ const char *callout_info,
+ struct key *dest_keyring)
{
struct key_user *user;
struct key *key;
+ kenter("%s,%s,%s,%p",
+ type->name, description, callout_info, dest_keyring);
+
/* search all the process keyrings for a key */
- key = search_process_keyrings_aux(type, description, type->match);
+ key = search_process_keyrings(type, description, type->match, current);
if (PTR_ERR(key) == -EAGAIN) {
/* the search failed, but the keyrings were searchable, so we
@@ -296,12 +381,13 @@ struct key *request_key(struct key_type *type,
/* - get hold of the user's construction queue */
user = key_user_lookup(current->fsuid);
- if (!user) {
- key = ERR_PTR(-ENOMEM);
- goto error;
- }
+ if (!user)
+ goto nomem;
+
+ do {
+ if (signal_pending(current))
+ goto interrupted;
- for (;;) {
/* ask userspace (returns NULL if it waited on a key
* being constructed) */
key = request_key_construction(type, description,
@@ -311,18 +397,46 @@ struct key *request_key(struct key_type *type,
/* someone else made the key we want, so we need to
* search again as it might now be available to us */
- key = search_process_keyrings_aux(type, description,
- type->match);
- if (PTR_ERR(key) != -EAGAIN)
- break;
- }
+ key = search_process_keyrings(type, description,
+ type->match, current);
+
+ } while (PTR_ERR(key) == -EAGAIN);
key_user_put(user);
+
+ /* link the new key into the appropriate keyring */
+ if (!PTR_ERR(key))
+ request_key_link(key, dest_keyring);
}
- error:
+error:
+ kleave(" = %p", key);
return key;
+nomem:
+ key = ERR_PTR(-ENOMEM);
+ goto error;
+
+interrupted:
+ key_user_put(user);
+ key = ERR_PTR(-EINTR);
+ goto error;
+
+} /* end request_key_and_link() */
+
+/*****************************************************************************/
+/*
+ * request a key
+ * - search the process's keyrings
+ * - check the list of keys being created or updated
+ * - call out to userspace for a key if supplementary info was provided
+ */
+struct key *request_key(struct key_type *type,
+ const char *description,
+ const char *callout_info)
+{
+ return request_key_and_link(type, description, callout_info, NULL);
+
} /* end request_key() */
EXPORT_SYMBOL(request_key);
@@ -339,7 +453,8 @@ int key_validate(struct key *key)
if (key) {
/* check it's still accessible */
ret = -EKEYREVOKED;
- if (key->flags & (KEY_FLAG_REVOKED | KEY_FLAG_DEAD))
+ if (test_bit(KEY_FLAG_REVOKED, &key->flags) ||
+ test_bit(KEY_FLAG_DEAD, &key->flags))
goto error;
/* check it hasn't expired */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-17 01:36:50 +0000