#include <linux/keyctl.h>
#include <linux/fs.h>
#include <linux/err.h>
+#include <linux/mutex.h>
#include <asm/uaccess.h>
#include "internal.h"
/* session keyring create vs join semaphore */
-static DECLARE_MUTEX(key_session_sem);
+static DEFINE_MUTEX(key_session_mutex);
/* the root user's tracking struct */
struct key_user root_key_user = {
.type = &key_type_keyring,
.user = &root_key_user,
.sem = __RWSEM_INITIALIZER(root_user_keyring.sem),
- .perm = KEY_POS_ALL | KEY_USR_ALL,
+ .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
.flags = 1 << KEY_FLAG_INSTANTIATED,
.description = "_uid.0",
#ifdef KEY_DEBUGGING
.type = &key_type_keyring,
.user = &root_key_user,
.sem = __RWSEM_INITIALIZER(root_session_keyring.sem),
- .perm = KEY_POS_ALL | KEY_USR_ALL,
+ .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
.flags = 1 << KEY_FLAG_INSTANTIATED,
.description = "_uid_ses.0",
#ifdef KEY_DEBUGGING
*/
int install_process_keyring(struct task_struct *tsk)
{
- unsigned long flags;
struct key *keyring;
char buf[20];
int ret;
+ might_sleep();
+
if (!tsk->signal->process_keyring) {
sprintf(buf, "_pid.%u", tsk->tgid);
}
/* attach keyring */
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
+ spin_lock_irq(&tsk->sighand->siglock);
if (!tsk->signal->process_keyring) {
tsk->signal->process_keyring = keyring;
keyring = NULL;
}
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+ spin_unlock_irq(&tsk->sighand->siglock);
key_put(keyring);
}
static int install_session_keyring(struct task_struct *tsk,
struct key *keyring)
{
- unsigned long flags;
struct key *old;
char buf[20];
- int ret;
+
+ might_sleep();
/* create an empty session keyring */
if (!keyring) {
sprintf(buf, "_ses.%u", tsk->tgid);
keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
- }
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
}
else {
atomic_inc(&keyring->usage);
}
/* install the keyring */
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- old = rcu_dereference(tsk->signal->session_keyring);
+ spin_lock_irq(&tsk->sighand->siglock);
+ old = tsk->signal->session_keyring;
rcu_assign_pointer(tsk->signal->session_keyring, keyring);
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+ spin_unlock_irq(&tsk->sighand->siglock);
- ret = 0;
+ /* we're using RCU on the pointer, but there's no point synchronising
+ * on it if it didn't previously point to anything */
+ if (old) {
+ synchronize_rcu();
+ key_put(old);
+ }
- /* we're using RCU on the pointer */
- synchronize_rcu();
- key_put(old);
-error:
- return ret;
+ return 0;
} /* end install_session_keyring() */
int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
{
key_check(tsk->thread_keyring);
+ key_check(tsk->request_key_auth);
/* no thread keyring yet */
tsk->thread_keyring = NULL;
+
+ /* copy the request_key() authorisation for this thread */
+ key_get(tsk->request_key_auth);
+
return 0;
} /* end copy_keys() */
/*****************************************************************************/
/*
- * dispose of keys upon thread exit
+ * dispose of per-thread keys upon thread exit
*/
void exit_keys(struct task_struct *tsk)
{
key_put(tsk->thread_keyring);
+ key_put(tsk->request_key_auth);
} /* end exit_keys() */
*/
int exec_keys(struct task_struct *tsk)
{
- unsigned long flags;
struct key *old;
/* newly exec'd tasks don't get a thread keyring */
key_put(old);
/* discard the process keyring from a newly exec'd task */
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
+ spin_lock_irq(&tsk->sighand->siglock);
old = tsk->signal->process_keyring;
tsk->signal->process_keyring = NULL;
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+ spin_unlock_irq(&tsk->sighand->siglock);
key_put(old);
struct task_struct *context)
{
struct request_key_auth *rka;
- key_ref_t key_ref, ret, err, instkey_ref;
+ key_ref_t key_ref, ret, err;
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
* searchable, but we failed to find a key or we found a negative key;
err = key_ref;
break;
}
-
- /* if this process has a session keyring and that has an
- * instantiation authorisation key in the bottom level, then we
- * also search the keyrings of the process mentioned there */
- if (context != current)
- goto no_key;
-
- rcu_read_lock();
- instkey_ref = __keyring_search_one(
- make_key_ref(rcu_dereference(
- context->signal->session_keyring),
- 1),
- &key_type_request_key_auth, NULL, 0);
- rcu_read_unlock();
-
- if (IS_ERR(instkey_ref))
- goto no_key;
-
- rka = key_ref_to_ptr(instkey_ref)->payload.data;
-
- key_ref = search_process_keyrings(type, description, match,
- rka->context);
- key_ref_put(instkey_ref);
-
+ }
+ /* or search the user-session keyring */
+ else {
+ key_ref = keyring_search_aux(
+ make_key_ref(context->user->session_keyring, 1),
+ context, type, description, match);
if (!IS_ERR(key_ref))
goto found;
break;
}
}
- /* or search the user-session keyring */
- else {
- key_ref = keyring_search_aux(
- make_key_ref(context->user->session_keyring, 1),
- context, type, description, match);
+
+ /* if this process has an instantiation authorisation key, then we also
+ * search the keyrings of the process mentioned there
+ * - we don't permit access to request_key auth keys via this method
+ */
+ if (context->request_key_auth &&
+ context == current &&
+ type != &key_type_request_key_auth &&
+ key_validate(context->request_key_auth) == 0
+ ) {
+ rka = context->request_key_auth->payload.data;
+
+ key_ref = search_process_keyrings(type, description, match,
+ rka->context);
+
if (!IS_ERR(key_ref))
goto found;
}
}
-
-no_key:
/* no key - decide on the error we're going to go for */
key_ref = ret ? ret : err;
key = ERR_PTR(-EINVAL);
goto error;
+ case KEY_SPEC_REQKEY_AUTH_KEY:
+ key = context->request_key_auth;
+ if (!key)
+ goto error;
+
+ atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
+ break;
+
default:
key_ref = ERR_PTR(-EINVAL);
if (id < 1)
goto invalid_key;
/* check the permissions */
- ret = -EACCES;
-
- if (!key_task_permission(key_ref, context, perm))
+ ret = key_task_permission(key_ref, context, perm);
+ if (ret < 0)
goto invalid_key;
error:
}
/* allow the user to join or create a named keyring */
- down(&key_session_sem);
+ mutex_lock(&key_session_mutex);
/* look for an existing keyring of this name */
keyring = find_keyring_by_name(name, 0);
key_put(keyring);
error2:
- up(&key_session_sem);
+ mutex_unlock(&key_session_mutex);
error:
return ret;
git.openpandora.org / pandora-kernel.git / blobdiff