-/* keyctl.c: userspace keyctl operations
+/* Userspace key control operations
*
* Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
+#include <linux/key.h>
#include <linux/keyctl.h>
#include <linux/fs.h>
#include <linux/capability.h>
+#include <linux/string.h>
#include <linux/err.h>
+#include <linux/vmalloc.h>
+#include <linux/security.h>
#include <asm/uaccess.h>
#include "internal.h"
-/*****************************************************************************/
+static int key_get_type_from_user(char *type,
+ const char __user *_type,
+ unsigned len)
+{
+ int ret;
+
+ ret = strncpy_from_user(type, _type, len);
+ if (ret < 0)
+ return ret;
+ if (ret == 0 || ret >= len)
+ return -EINVAL;
+ if (type[0] == '.')
+ return -EPERM;
+ type[len - 1] = '\0';
+ return 0;
+}
+
/*
- * extract the description of a new key from userspace and either add it as a
- * new key to the specified keyring or update a matching key in that keyring
- * - the keyring must be writable
- * - returns the new key's serial number
- * - implements add_key()
+ * Extract the description of a new key from userspace and either add it as a
+ * new key to the specified keyring or update a matching key in that keyring.
+ *
+ * The keyring must be writable so that we can attach the key to it.
+ *
+ * If successful, the new key's serial number is returned, otherwise an error
+ * code is returned.
*/
-asmlinkage long sys_add_key(const char __user *_type,
- const char __user *_description,
- const void __user *_payload,
- size_t plen,
- key_serial_t ringid)
+SYSCALL_DEFINE5(add_key, const char __user *, _type,
+ const char __user *, _description,
+ const void __user *, _payload,
+ size_t, plen,
+ key_serial_t, ringid)
{
key_ref_t keyring_ref, key_ref;
char type[32], *description;
void *payload;
- long dlen, ret;
+ long ret;
+ bool vm;
ret = -EINVAL;
- if (plen > 32767)
+ if (plen > 1024 * 1024 - 1)
goto error;
/* draw all the data into kernel space */
- ret = strncpy_from_user(type, _type, sizeof(type) - 1);
+ ret = key_get_type_from_user(type, _type, sizeof(type));
if (ret < 0)
goto error;
- type[31] = '\0';
- ret = -EPERM;
- if (type[0] == '.')
- goto error;
-
- ret = -EFAULT;
- dlen = strnlen_user(_description, PAGE_SIZE - 1);
- if (dlen <= 0)
- goto error;
-
- ret = -EINVAL;
- if (dlen > PAGE_SIZE - 1)
- goto error;
-
- ret = -ENOMEM;
- description = kmalloc(dlen + 1, GFP_KERNEL);
- if (!description)
+ description = strndup_user(_description, PAGE_SIZE);
+ if (IS_ERR(description)) {
+ ret = PTR_ERR(description);
goto error;
-
- ret = -EFAULT;
- if (copy_from_user(description, _description, dlen + 1) != 0)
- goto error2;
+ }
/* pull the payload in if one was supplied */
payload = NULL;
+ vm = false;
if (_payload) {
ret = -ENOMEM;
- payload = kmalloc(plen, GFP_KERNEL);
- if (!payload)
- goto error2;
+ payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN);
+ if (!payload) {
+ if (plen <= PAGE_SIZE)
+ goto error2;
+ vm = true;
+ payload = vmalloc(plen);
+ if (!payload)
+ goto error2;
+ }
ret = -EFAULT;
if (copy_from_user(payload, _payload, plen) != 0)
}
/* find the target keyring (which must be writable) */
- keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
+ keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
goto error3;
/* create or update the requested key and add it to the target
* keyring */
key_ref = key_create_or_update(keyring_ref, type, description,
- payload, plen, 0);
+ payload, plen, KEY_PERM_UNDEF,
+ KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key_ref)) {
ret = key_ref_to_ptr(key_ref)->serial;
key_ref_put(key_ref);
key_ref_put(keyring_ref);
error3:
- kfree(payload);
+ if (!vm)
+ kfree(payload);
+ else
+ vfree(payload);
error2:
kfree(description);
error:
return ret;
+}
-} /* end sys_add_key() */
-
-/*****************************************************************************/
/*
- * search the process keyrings for a matching key
- * - nested keyrings may also be searched if they have Search permission
- * - if a key is found, it will be attached to the destination keyring if
- * there's one specified
- * - /sbin/request-key will be invoked if _callout_info is non-NULL
- * - the _callout_info string will be passed to /sbin/request-key
- * - if the _callout_info string is empty, it will be rendered as "-"
- * - implements request_key()
+ * Search the process keyrings and keyring trees linked from those for a
+ * matching key. Keyrings must have appropriate Search permission to be
+ * searched.
+ *
+ * If a key is found, it will be attached to the destination keyring if there's
+ * one specified and the serial number of the key will be returned.
+ *
+ * If no key is found, /sbin/request-key will be invoked if _callout_info is
+ * non-NULL in an attempt to create a key. The _callout_info string will be
+ * passed to /sbin/request-key to aid with completing the request. If the
+ * _callout_info string is "" then it will be changed to "-".
*/
-asmlinkage long sys_request_key(const char __user *_type,
- const char __user *_description,
- const char __user *_callout_info,
- key_serial_t destringid)
+SYSCALL_DEFINE4(request_key, const char __user *, _type,
+ const char __user *, _description,
+ const char __user *, _callout_info,
+ key_serial_t, destringid)
{
struct key_type *ktype;
struct key *key;
key_ref_t dest_ref;
+ size_t callout_len;
char type[32], *description, *callout_info;
- long dlen, ret;
+ long ret;
/* pull the type into kernel space */
- ret = strncpy_from_user(type, _type, sizeof(type) - 1);
+ ret = key_get_type_from_user(type, _type, sizeof(type));
if (ret < 0)
goto error;
- type[31] = '\0';
-
- ret = -EPERM;
- if (type[0] == '.')
- goto error;
/* pull the description into kernel space */
- ret = -EFAULT;
- dlen = strnlen_user(_description, PAGE_SIZE - 1);
- if (dlen <= 0)
- goto error;
-
- ret = -EINVAL;
- if (dlen > PAGE_SIZE - 1)
- goto error;
-
- ret = -ENOMEM;
- description = kmalloc(dlen + 1, GFP_KERNEL);
- if (!description)
+ description = strndup_user(_description, PAGE_SIZE);
+ if (IS_ERR(description)) {
+ ret = PTR_ERR(description);
goto error;
-
- ret = -EFAULT;
- if (copy_from_user(description, _description, dlen + 1) != 0)
- goto error2;
+ }
/* pull the callout info into kernel space */
callout_info = NULL;
+ callout_len = 0;
if (_callout_info) {
- ret = -EFAULT;
- dlen = strnlen_user(_callout_info, PAGE_SIZE - 1);
- if (dlen <= 0)
- goto error2;
-
- ret = -EINVAL;
- if (dlen > PAGE_SIZE - 1)
+ callout_info = strndup_user(_callout_info, PAGE_SIZE);
+ if (IS_ERR(callout_info)) {
+ ret = PTR_ERR(callout_info);
goto error2;
-
- ret = -ENOMEM;
- callout_info = kmalloc(dlen + 1, GFP_KERNEL);
- if (!callout_info)
- goto error2;
-
- ret = -EFAULT;
- if (copy_from_user(callout_info, _callout_info, dlen + 1) != 0)
- goto error3;
+ }
+ callout_len = strlen(callout_info);
}
/* get the destination keyring if specified */
dest_ref = NULL;
if (destringid) {
- dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE);
+ dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
+ KEY_WRITE);
if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref);
goto error3;
/* do the search */
key = request_key_and_link(ktype, description, callout_info,
- key_ref_to_ptr(dest_ref));
+ callout_len, NULL, key_ref_to_ptr(dest_ref),
+ KEY_ALLOC_IN_QUOTA);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error5;
}
+ /* wait for the key to finish being constructed */
+ ret = wait_for_key_construction(key, 1);
+ if (ret < 0)
+ goto error6;
+
ret = key->serial;
+error6:
key_put(key);
- error5:
+error5:
key_type_put(ktype);
- error4:
+error4:
key_ref_put(dest_ref);
- error3:
+error3:
kfree(callout_info);
- error2:
+error2:
kfree(description);
- error:
+error:
return ret;
+}
-} /* end sys_request_key() */
-
-/*****************************************************************************/
/*
- * get the ID of the specified process keyring
- * - the keyring must have search permission to be found
- * - implements keyctl(KEYCTL_GET_KEYRING_ID)
+ * Get the ID of the specified process keyring.
+ *
+ * The requested keyring must have search permission to be found.
+ *
+ * If successful, the ID of the requested keyring will be returned.
*/
long keyctl_get_keyring_ID(key_serial_t id, int create)
{
key_ref_t key_ref;
+ unsigned long lflags;
long ret;
- key_ref = lookup_user_key(NULL, id, create, 0, KEY_SEARCH);
+ lflags = create ? KEY_LOOKUP_CREATE : 0;
+ key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
ret = key_ref_to_ptr(key_ref)->serial;
key_ref_put(key_ref);
- error:
+error:
return ret;
+}
-} /* end keyctl_get_keyring_ID() */
-
-/*****************************************************************************/
/*
- * join the session keyring
- * - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING)
+ * Join a (named) session keyring.
+ *
+ * Create and join an anonymous session keyring or join a named session
+ * keyring, creating it if necessary. A named session keyring must have Search
+ * permission for it to be joined. Session keyrings without this permit will
+ * be skipped over.
+ *
+ * If successful, the ID of the joined session keyring will be returned.
*/
long keyctl_join_session_keyring(const char __user *_name)
{
char *name;
- long nlen, ret;
+ long ret;
/* fetch the name from userspace */
name = NULL;
if (_name) {
- ret = -EFAULT;
- nlen = strnlen_user(_name, PAGE_SIZE - 1);
- if (nlen <= 0)
- goto error;
-
- ret = -EINVAL;
- if (nlen > PAGE_SIZE - 1)
- goto error;
-
- ret = -ENOMEM;
- name = kmalloc(nlen + 1, GFP_KERNEL);
- if (!name)
+ name = strndup_user(_name, PAGE_SIZE);
+ if (IS_ERR(name)) {
+ ret = PTR_ERR(name);
goto error;
-
- ret = -EFAULT;
- if (copy_from_user(name, _name, nlen + 1) != 0)
- goto error2;
+ }
}
/* join the session */
ret = join_session_keyring(name);
-
- error2:
kfree(name);
- error:
- return ret;
-} /* end keyctl_join_session_keyring() */
+error:
+ return ret;
+}
-/*****************************************************************************/
/*
- * update a key's data payload
- * - the key must be writable
- * - implements keyctl(KEYCTL_UPDATE)
+ * Update a key's data payload from the given data.
+ *
+ * The key must grant the caller Write permission and the key type must support
+ * updating for this to work. A negative key can be positively instantiated
+ * with this call.
+ *
+ * If successful, 0 will be returned. If the key type does not support
+ * updating, then -EOPNOTSUPP will be returned.
*/
long keyctl_update_key(key_serial_t id,
const void __user *_payload,
}
/* find the target key (which must be writable) */
- key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE);
+ key_ref = lookup_user_key(id, 0, KEY_WRITE);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error2;
ret = key_update(key_ref, payload, plen);
key_ref_put(key_ref);
- error2:
+error2:
kfree(payload);
- error:
+error:
return ret;
+}
-} /* end keyctl_update_key() */
-
-/*****************************************************************************/
/*
- * revoke a key
- * - the key must be writable
- * - implements keyctl(KEYCTL_REVOKE)
+ * Revoke a key.
+ *
+ * The key must be grant the caller Write or Setattr permission for this to
+ * work. The key type should give up its quota claim when revoked. The key
+ * and any links to the key will be automatically garbage collected after a
+ * certain amount of time (/proc/sys/kernel/keys/gc_delay).
+ *
+ * If successful, 0 is returned.
*/
long keyctl_revoke_key(key_serial_t id)
{
key_ref_t key_ref;
long ret;
- key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE);
+ key_ref = lookup_user_key(id, 0, KEY_WRITE);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
- goto error;
+ if (ret != -EACCES)
+ goto error;
+ key_ref = lookup_user_key(id, 0, KEY_SETATTR);
+ if (IS_ERR(key_ref)) {
+ ret = PTR_ERR(key_ref);
+ goto error;
+ }
}
key_revoke(key_ref_to_ptr(key_ref));
ret = 0;
key_ref_put(key_ref);
- error:
+error:
return ret;
+}
-} /* end keyctl_revoke_key() */
+/*
+ * Invalidate a key.
+ *
+ * The key must be grant the caller Invalidate permission for this to work.
+ * The key and any links to the key will be automatically garbage collected
+ * immediately.
+ *
+ * If successful, 0 is returned.
+ */
+long keyctl_invalidate_key(key_serial_t id)
+{
+ key_ref_t key_ref;
+ long ret;
+
+ kenter("%d", id);
+
+ key_ref = lookup_user_key(id, 0, KEY_SEARCH);
+ if (IS_ERR(key_ref)) {
+ ret = PTR_ERR(key_ref);
+ goto error;
+ }
+
+ key_invalidate(key_ref_to_ptr(key_ref));
+ ret = 0;
+
+ key_ref_put(key_ref);
+error:
+ kleave(" = %ld", ret);
+ return ret;
+}
-/*****************************************************************************/
/*
- * clear the specified process keyring
- * - the keyring must be writable
- * - implements keyctl(KEYCTL_CLEAR)
+ * Clear the specified keyring, creating an empty process keyring if one of the
+ * special keyring IDs is used.
+ *
+ * The keyring must grant the caller Write permission for this to work. If
+ * successful, 0 will be returned.
*/
long keyctl_keyring_clear(key_serial_t ringid)
{
key_ref_t keyring_ref;
long ret;
- keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
+ keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
+
+ /* Root is permitted to invalidate certain special keyrings */
+ if (capable(CAP_SYS_ADMIN)) {
+ keyring_ref = lookup_user_key(ringid, 0, 0);
+ if (IS_ERR(keyring_ref))
+ goto error;
+ if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
+ &key_ref_to_ptr(keyring_ref)->flags))
+ goto clear;
+ goto error_put;
+ }
+
goto error;
}
+clear:
ret = keyring_clear(key_ref_to_ptr(keyring_ref));
-
+error_put:
key_ref_put(keyring_ref);
- error:
+error:
return ret;
+}
-} /* end keyctl_keyring_clear() */
-
-/*****************************************************************************/
/*
- * link a key into a keyring
- * - the keyring must be writable
- * - the key must be linkable
- * - implements keyctl(KEYCTL_LINK)
+ * 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(NULL, ringid, 1, 0, KEY_WRITE);
+ 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(NULL, id, 1, 0, KEY_LINK);
+ 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:
+error2:
key_ref_put(keyring_ref);
- error:
+error:
return ret;
+}
-} /* end keyctl_keyring_link() */
-
-/*****************************************************************************/
/*
- * unlink the first attachment of a key from a keyring
- * - the keyring must be writable
- * - we don't need any permissions on the key
- * - implements keyctl(KEYCTL_UNLINK)
+ * 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(NULL, ringid, 0, 0, KEY_WRITE);
+ 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(NULL, id, 0, 0, 0);
+ 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:
+error2:
key_ref_put(keyring_ref);
- error:
+error:
return ret;
+}
-} /* end keyctl_keyring_unlink() */
-
-/*****************************************************************************/
/*
- * describe a user key
- * - the key must have view permission
- * - if there's a buffer, we place up to buflen bytes of data into it
- * - unless there's an error, we return the amount of description available,
- * irrespective of how much we may have copied
- * - the description is formatted thus:
+ * 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>
- * - implements keyctl(KEYCTL_DESCRIBE)
+ *
+ * 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,
char *tmpbuf;
long ret;
- key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW);
+ 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 */
instkey = key_get_instantiation_authkey(keyid);
if (!IS_ERR(instkey)) {
key_put(instkey);
- key_ref = lookup_user_key(NULL, keyid,
- 0, 1, 0);
+ key_ref = lookup_user_key(keyid,
+ KEY_LOOKUP_PARTIAL,
+ 0);
if (!IS_ERR(key_ref))
goto okay;
}
ret = snprintf(tmpbuf, PAGE_SIZE - 1,
"%s;%d;%d;%08x;%s",
- key_ref_to_ptr(key_ref)->type->name,
- key_ref_to_ptr(key_ref)->uid,
- key_ref_to_ptr(key_ref)->gid,
- key_ref_to_ptr(key_ref)->perm,
- key_ref_to_ptr(key_ref)->description ?
- key_ref_to_ptr(key_ref)->description : ""
- );
+ key->type->name,
+ key->uid,
+ key->gid,
+ key->perm,
+ key->description ?: "");
/* include a NUL char at the end of the data */
if (ret > PAGE_SIZE - 1)
}
kfree(tmpbuf);
- error2:
+error2:
key_ref_put(key_ref);
- error:
+error:
return ret;
+}
-} /* end keyctl_describe_key() */
-
-/*****************************************************************************/
/*
- * search the specified keyring for a matching key
- * - the start keyring must be searchable
- * - nested keyrings may also be searched if they are searchable
- * - only keys with search permission may be found
- * - if a key is found, it will be attached to the destination keyring if
- * there's one specified
- * - implements keyctl(KEYCTL_SEARCH)
+ * 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,
struct key_type *ktype;
key_ref_t keyring_ref, key_ref, dest_ref;
char type[32], *description;
- long dlen, ret;
+ long ret;
/* pull the type and description into kernel space */
- ret = strncpy_from_user(type, _type, sizeof(type) - 1);
+ ret = key_get_type_from_user(type, _type, sizeof(type));
if (ret < 0)
goto error;
- type[31] = '\0';
-
- ret = -EFAULT;
- dlen = strnlen_user(_description, PAGE_SIZE - 1);
- if (dlen <= 0)
- goto error;
- ret = -EINVAL;
- if (dlen > PAGE_SIZE - 1)
+ description = strndup_user(_description, PAGE_SIZE);
+ if (IS_ERR(description)) {
+ ret = PTR_ERR(description);
goto error;
-
- ret = -ENOMEM;
- description = kmalloc(dlen + 1, GFP_KERNEL);
- if (!description)
- goto error;
-
- ret = -EFAULT;
- if (copy_from_user(description, _description, dlen + 1) != 0)
- goto error2;
+ }
/* get the keyring at which to begin the search */
- keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_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(NULL, destringid, 1, 0, KEY_WRITE);
+ dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
+ KEY_WRITE);
if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref);
goto error3;
ret = key_ref_to_ptr(key_ref)->serial;
- error6:
+error6:
key_ref_put(key_ref);
- error5:
+error5:
key_type_put(ktype);
- error4:
+error4:
key_ref_put(dest_ref);
- error3:
+error3:
key_ref_put(keyring_ref);
- error2:
+error2:
kfree(description);
- error:
+error:
return ret;
+}
-} /* end keyctl_keyring_search() */
-
-/*****************************************************************************/
/*
- * read a user key's payload
- * - the keyring must be readable or the key must be searchable from the
- * process's keyrings
- * - if there's a buffer, we place up to buflen bytes of data into it
- * - unless there's an error, we return the amount of data in the key,
- * irrespective of how much we may have copied
- * - implements keyctl(KEYCTL_READ)
+ * 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)
{
long ret;
/* find the key first */
- key_ref = lookup_user_key(NULL, keyid, 0, 0, 0);
+ key_ref = lookup_user_key(keyid, 0, 0);
if (IS_ERR(key_ref)) {
ret = -ENOKEY;
goto error;
}
/* the key is probably readable - now try to read it */
- can_read_key:
+can_read_key:
ret = key_validate(key);
if (ret == 0) {
ret = -EOPNOTSUPP;
}
}
- error2:
+error2:
key_put(key);
- error:
+error:
return ret;
+}
-} /* end keyctl_read_key() */
-
-/*****************************************************************************/
/*
- * change the ownership of a key
- * - the keyring owned by the changer
- * - if the uid or gid is -1, then that parameter is not changed
- * - implements keyctl(KEYCTL_CHOWN)
+ * 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 uid, gid_t gid)
{
+ struct key_user *newowner, *zapowner = NULL;
struct key *key;
key_ref_t key_ref;
long ret;
if (uid == (uid_t) -1 && gid == (gid_t) -1)
goto error;
- key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR);
+ 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;
if (!capable(CAP_SYS_ADMIN)) {
/* only the sysadmin can chown a key to some other UID */
if (uid != (uid_t) -1 && key->uid != uid)
- goto no_access;
+ goto error_put;
/* only the sysadmin can set the key's GID to a group other
* than one of those that the current process subscribes to */
if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid))
- goto no_access;
+ goto error_put;
}
- /* change the UID (have to update the quotas) */
+ /* change the UID */
if (uid != (uid_t) -1 && uid != key->uid) {
- /* don't support UID changing yet */
- ret = -EOPNOTSUPP;
- goto no_access;
+ ret = -ENOMEM;
+ newowner = key_user_lookup(uid, current_user_ns());
+ if (!newowner)
+ goto error_put;
+
+ /* transfer the quota burden to the new user */
+ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
+ unsigned maxkeys = (uid == 0) ?
+ key_quota_root_maxkeys : key_quota_maxkeys;
+ unsigned maxbytes = (uid == 0) ?
+ key_quota_root_maxbytes : key_quota_maxbytes;
+
+ spin_lock(&newowner->lock);
+ if (newowner->qnkeys + 1 >= maxkeys ||
+ newowner->qnbytes + key->quotalen >= maxbytes ||
+ newowner->qnbytes + key->quotalen <
+ newowner->qnbytes)
+ goto quota_overrun;
+
+ newowner->qnkeys++;
+ newowner->qnbytes += key->quotalen;
+ spin_unlock(&newowner->lock);
+
+ spin_lock(&key->user->lock);
+ key->user->qnkeys--;
+ key->user->qnbytes -= key->quotalen;
+ spin_unlock(&key->user->lock);
+ }
+
+ atomic_dec(&key->user->nkeys);
+ atomic_inc(&newowner->nkeys);
+
+ if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
+ atomic_dec(&key->user->nikeys);
+ atomic_inc(&newowner->nikeys);
+ }
+
+ zapowner = key->user;
+ key->user = newowner;
+ key->uid = uid;
}
/* change the GID */
ret = 0;
- no_access:
+error_put:
up_write(&key->sem);
key_put(key);
- error:
+ if (zapowner)
+ key_user_put(zapowner);
+error:
return ret;
-} /* end keyctl_chown_key() */
+quota_overrun:
+ spin_unlock(&newowner->lock);
+ zapowner = newowner;
+ ret = -EDQUOT;
+ goto error_put;
+}
-/*****************************************************************************/
/*
- * change the permission mask on a key
- * - the keyring owned by the changer
- * - implements keyctl(KEYCTL_SETPERM)
+ * 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)
{
if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
goto error;
- key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR);
+ 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;
down_write(&key->sem);
/* if we're not the sysadmin, we can only change a key that we own */
- if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) {
+ if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) {
key->perm = perm;
ret = 0;
}
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;
-} /* end keyctl_setperm_key() */
+ /* 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;
+}
-/*****************************************************************************/
/*
- * instantiate the key with the specified payload, and, if one is given, link
- * the key into the keyring
+ * Change the request_key authorisation key on the current process.
*/
-long keyctl_instantiate_key(key_serial_t id,
- const void __user *_payload,
- size_t plen,
- key_serial_t ringid)
+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;
- key_ref_t keyring_ref;
+ struct key *instkey, *dest_keyring;
void *payload;
long ret;
+ bool vm = false;
+
+ kenter("%d,,%zu,%d", id, plen, ringid);
ret = -EINVAL;
- if (plen > 32767)
+ if (plen > 1024 * 1024 - 1)
goto error;
/* the appropriate instantiation authorisation key must have been
* assumed before calling this */
ret = -EPERM;
- instkey = current->request_key_auth;
+ instkey = cred->request_key_auth;
if (!instkey)
goto error;
/* pull the payload in if one was supplied */
payload = NULL;
- if (_payload) {
+ if (payload_iov) {
ret = -ENOMEM;
payload = kmalloc(plen, GFP_KERNEL);
- if (!payload)
- goto error;
+ if (!payload) {
+ if (plen <= PAGE_SIZE)
+ goto error;
+ vm = true;
+ payload = vmalloc(plen);
+ if (!payload)
+ goto error;
+ }
- ret = -EFAULT;
- if (copy_from_user(payload, _payload, plen) != 0)
+ 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 */
- keyring_ref = NULL;
- if (ringid) {
- keyring_ref = lookup_user_key(rka->context, ringid, 1, 0,
- KEY_WRITE);
- if (IS_ERR(keyring_ref)) {
- ret = PTR_ERR(keyring_ref);
- goto error2;
- }
- }
+ 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,
- key_ref_to_ptr(keyring_ref), instkey);
+ dest_keyring, instkey);
- key_ref_put(keyring_ref);
+ key_put(dest_keyring);
/* discard the assumed authority if it's just been disabled by
* instantiation of the key */
- if (ret == 0) {
- key_put(current->request_key_auth);
- current->request_key_auth = NULL;
- }
+ if (ret == 0)
+ keyctl_change_reqkey_auth(NULL);
error2:
- kfree(payload);
+ if (!vm)
+ kfree(payload);
+ else
+ vfree(payload);
error:
return ret;
+}
-} /* end keyctl_instantiate_key() */
+/*
+ * 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);
+}
-/*****************************************************************************/
/*
- * negatively instantiate the key with the given timeout (in seconds), and, if
- * one is given, link the key into the keyring
+ * 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 == 0 || ioc == 0)
+ goto no_payload;
+
+ ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
+ ARRAY_SIZE(iovstack), iovstack, &iov, 1);
+ 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;
- key_ref_t keyring_ref;
+ 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 = current->request_key_auth;
+ instkey = cred->request_key_auth;
if (!instkey)
goto error;
/* find the destination keyring if present (which must also be
* writable) */
- keyring_ref = NULL;
- if (ringid) {
- keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
- if (IS_ERR(keyring_ref)) {
- ret = PTR_ERR(keyring_ref);
- goto error;
- }
- }
+ ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
+ if (ret < 0)
+ goto error;
/* instantiate the key and link it into a keyring */
- ret = key_negate_and_link(rka->target_key, timeout,
- key_ref_to_ptr(keyring_ref), instkey);
+ ret = key_reject_and_link(rka->target_key, timeout, error,
+ dest_keyring, instkey);
- key_ref_put(keyring_ref);
+ key_put(dest_keyring);
/* discard the assumed authority if it's just been disabled by
* instantiation of the key */
- if (ret == 0) {
- key_put(current->request_key_auth);
- current->request_key_auth = NULL;
- }
+ if (ret == 0)
+ keyctl_change_reqkey_auth(NULL);
error:
return ret;
+}
-} /* end keyctl_negate_key() */
-
-/*****************************************************************************/
/*
- * set the default keyring in which request_key() will cache keys
- * - return the old setting
+ * 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)
{
- int ret;
+ 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(current);
+ ret = install_thread_keyring_to_cred(new);
if (ret < 0)
- return ret;
+ goto error;
goto set;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
- ret = install_process_keyring(current);
- if (ret < 0)
- return ret;
+ 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:
- set:
- current->jit_keyring = reqkey_defl;
+ case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+ goto set;
case KEY_REQKEY_DEFL_NO_CHANGE:
- return current->jit_keyring;
-
case KEY_REQKEY_DEFL_GROUP_KEYRING:
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto error;
}
-} /* end keyctl_set_reqkey_keyring() */
+set:
+ new->jit_keyring = reqkey_defl;
+ commit_creds(new);
+ return old_setting;
+error:
+ abort_creds(new);
+ return ret;
+}
-/*****************************************************************************/
/*
- * set or clear the timeout for a key
+ * 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 timespec now;
- struct key *key;
+ struct key *key, *instkey;
key_ref_t key_ref;
- time_t expiry;
long ret;
- key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR);
+ 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);
-
- /* make the changes with the locks held to prevent races */
- down_write(&key->sem);
-
- expiry = 0;
- if (timeout > 0) {
- now = current_kernel_time();
- expiry = now.tv_sec + timeout;
- }
-
- key->expiry = expiry;
-
- up_write(&key->sem);
+ key_set_timeout(key, timeout);
key_put(key);
ret = 0;
error:
return ret;
+}
-} /* end keyctl_set_timeout() */
-
-/*****************************************************************************/
/*
- * assume the authority to instantiate the specified key
+ * 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)
{
/* we divest ourselves of authority if given an ID of 0 */
if (id == 0) {
- key_put(current->request_key_auth);
- current->request_key_auth = NULL;
- ret = 0;
+ ret = keyctl_change_reqkey_auth(NULL);
goto error;
}
goto error;
}
- key_put(current->request_key_auth);
- current->request_key_auth = authkey;
- ret = authkey->serial;
+ ret = keyctl_change_reqkey_auth(authkey);
+ if (ret < 0)
+ goto error;
+ key_put(authkey);
+ ret = authkey->serial;
error:
return ret;
+}
-} /* end keyctl_assume_authority() */
+/*
+ * Get 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;
+}
-/*****************************************************************************/
/*
- * the key control system call
+ * 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.
*/
-asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
- unsigned long arg4, unsigned long arg5)
+long keyctl_session_to_parent(void)
+{
+#ifdef TIF_NOTIFY_RESUME
+ struct task_struct *me, *parent;
+ const struct cred *mycred, *pcred;
+ struct cred *cred, *oldcred;
+ key_ref_t keyring_r;
+ int ret;
+
+ keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
+ if (IS_ERR(keyring_r))
+ return PTR_ERR(keyring_r);
+
+ /* 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 */
+ ret = -ENOMEM;
+ cred = cred_alloc_blank();
+ if (!cred)
+ goto error_keyring;
+
+ cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
+ keyring_r = NULL;
+
+ me = current;
+ rcu_read_lock();
+ write_lock_irq(&tasklist_lock);
+
+ parent = me->real_parent;
+ ret = -EPERM;
+
+ /* the parent mustn't be init and mustn't be a kernel thread */
+ if (parent->pid <= 1 || !parent->mm)
+ goto not_permitted;
+
+ /* the parent must be single threaded */
+ if (!thread_group_empty(parent))
+ goto not_permitted;
+
+ /* 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)
+ goto already_same;
+
+ /* the parent must have the same effective ownership and mustn't be
+ * SUID/SGID */
+ if (pcred->uid != mycred->euid ||
+ pcred->euid != mycred->euid ||
+ pcred->suid != mycred->euid ||
+ pcred->gid != mycred->egid ||
+ pcred->egid != mycred->egid ||
+ pcred->sgid != mycred->egid)
+ goto not_permitted;
+
+ /* the keyrings must have the same UID */
+ if ((pcred->tgcred->session_keyring &&
+ pcred->tgcred->session_keyring->uid != mycred->euid) ||
+ mycred->tgcred->session_keyring->uid != mycred->euid)
+ goto not_permitted;
+
+ /* if there's an already pending keyring replacement, then we replace
+ * that */
+ oldcred = parent->replacement_session_keyring;
+
+ /* the replacement session keyring is applied just prior to userspace
+ * restarting */
+ parent->replacement_session_keyring = cred;
+ cred = NULL;
+ set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
+
+ write_unlock_irq(&tasklist_lock);
+ rcu_read_unlock();
+ if (oldcred)
+ put_cred(oldcred);
+ return 0;
+
+already_same:
+ ret = 0;
+not_permitted:
+ write_unlock_irq(&tasklist_lock);
+ rcu_read_unlock();
+ put_cred(cred);
+ return ret;
+
+error_keyring:
+ key_ref_put(keyring_r);
+ return ret;
+
+#else /* !TIF_NOTIFY_RESUME */
+ /*
+ * To be removed when TIF_NOTIFY_RESUME has been implemented on
+ * m68k/xtensa
+ */
+#warning TIF_NOTIFY_RESUME not implemented
+ return -EOPNOTSUPP;
+#endif /* !TIF_NOTIFY_RESUME */
+}
+
+/*
+ * 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:
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;
}
-
-} /* end sys_keyctl() */
+}