074d589895
The 'struct key' will use 'time_t' which we try to remove in the kernel, since 'time_t' is not year 2038 safe on 32bit systems. Also the 'struct keyring_search_context' will use 'timespec' type to record current time, which is also not year 2038 safe on 32bit systems. Thus this patch replaces 'time_t' with 'time64_t' which is year 2038 safe for 'struct key', and replace 'timespec' with 'time64_t' for the 'struct keyring_search_context', since we only look at the the seconds part of 'timespec' variable. Moreover we also change the codes where using the 'time_t' and 'timespec', and we can get current time by ktime_get_real_seconds() instead of current_kernel_time(), and use 'TIME64_MAX' macro to initialize the 'time64_t' type variable. Especially in proc.c file, we have replaced 'unsigned long' and 'timespec' type with 'u64' and 'time64_t' type to save the timeout value, which means user will get one 'u64' type timeout value by issuing proc_keys_show() function. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com>
110 lines
2.9 KiB
C
110 lines
2.9 KiB
C
/* Key permission checking
|
|
*
|
|
* Copyright (C) 2005 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.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/security.h>
|
|
#include "internal.h"
|
|
|
|
/**
|
|
* key_task_permission - Check a key can be used
|
|
* @key_ref: The key to check.
|
|
* @cred: The credentials to use.
|
|
* @perm: The permissions to check for.
|
|
*
|
|
* Check to see whether permission is granted to use a key in the desired way,
|
|
* but permit the security modules to override.
|
|
*
|
|
* The caller must hold either a ref on cred or must hold the RCU readlock.
|
|
*
|
|
* Returns 0 if successful, -EACCES if access is denied based on the
|
|
* permissions bits or the LSM check.
|
|
*/
|
|
int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
|
|
unsigned perm)
|
|
{
|
|
struct key *key;
|
|
key_perm_t kperm;
|
|
int ret;
|
|
|
|
key = key_ref_to_ptr(key_ref);
|
|
|
|
/* use the second 8-bits of permissions for keys the caller owns */
|
|
if (uid_eq(key->uid, cred->fsuid)) {
|
|
kperm = key->perm >> 16;
|
|
goto use_these_perms;
|
|
}
|
|
|
|
/* use the third 8-bits of permissions for keys the caller has a group
|
|
* membership in common with */
|
|
if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) {
|
|
if (gid_eq(key->gid, cred->fsgid)) {
|
|
kperm = key->perm >> 8;
|
|
goto use_these_perms;
|
|
}
|
|
|
|
ret = groups_search(cred->group_info, key->gid);
|
|
if (ret) {
|
|
kperm = key->perm >> 8;
|
|
goto use_these_perms;
|
|
}
|
|
}
|
|
|
|
/* otherwise use the least-significant 8-bits */
|
|
kperm = key->perm;
|
|
|
|
use_these_perms:
|
|
|
|
/* use the top 8-bits of permissions for keys the caller possesses
|
|
* - possessor permissions are additive with other permissions
|
|
*/
|
|
if (is_key_possessed(key_ref))
|
|
kperm |= key->perm >> 24;
|
|
|
|
kperm = kperm & perm & KEY_NEED_ALL;
|
|
|
|
if (kperm != perm)
|
|
return -EACCES;
|
|
|
|
/* let LSM be the final arbiter */
|
|
return security_key_permission(key_ref, cred, perm);
|
|
}
|
|
EXPORT_SYMBOL(key_task_permission);
|
|
|
|
/**
|
|
* key_validate - Validate a key.
|
|
* @key: The key to be validated.
|
|
*
|
|
* Check that a key is valid, returning 0 if the key is okay, -ENOKEY if the
|
|
* key is invalidated, -EKEYREVOKED if the key's type has been removed or if
|
|
* the key has been revoked or -EKEYEXPIRED if the key has expired.
|
|
*/
|
|
int key_validate(const struct key *key)
|
|
{
|
|
unsigned long flags = READ_ONCE(key->flags);
|
|
time64_t expiry = READ_ONCE(key->expiry);
|
|
|
|
if (flags & (1 << KEY_FLAG_INVALIDATED))
|
|
return -ENOKEY;
|
|
|
|
/* check it's still accessible */
|
|
if (flags & ((1 << KEY_FLAG_REVOKED) |
|
|
(1 << KEY_FLAG_DEAD)))
|
|
return -EKEYREVOKED;
|
|
|
|
/* check it hasn't expired */
|
|
if (expiry) {
|
|
if (ktime_get_real_seconds() >= expiry)
|
|
return -EKEYEXPIRED;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(key_validate);
|