Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* General persistent per-UID keyrings register
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Written by David Howells (dhowells@redhat.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/user_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/cred.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  * Create the persistent keyring register for the current user namespace.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  * Called with the namespace's sem locked for writing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) static int key_create_persistent_register(struct user_namespace *ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	struct key *reg = keyring_alloc(".persistent_register",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 					KUIDT_INIT(0), KGIDT_INIT(0),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 					current_cred(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 					((KEY_POS_ALL & ~KEY_POS_SETATTR) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 					 KEY_USR_VIEW | KEY_USR_READ),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 					KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	if (IS_ERR(reg))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 		return PTR_ERR(reg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	ns->persistent_keyring_register = reg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  * Create the persistent keyring for the specified user.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38)  * Called with the namespace's sem locked for writing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 				       struct keyring_index_key *index_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	struct key *persistent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	key_ref_t reg_ref, persistent_ref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	if (!ns->persistent_keyring_register) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		long err = key_create_persistent_register(ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 		if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 			return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 		reg_ref = make_key_ref(ns->persistent_keyring_register, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		persistent_ref = find_key_to_update(reg_ref, index_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		if (persistent_ref)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 			return persistent_ref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	persistent = keyring_alloc(index_key->description,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 				   uid, INVALID_GID, current_cred(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 				    KEY_USR_VIEW | KEY_USR_READ),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 				   KEY_ALLOC_NOT_IN_QUOTA, NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 				   ns->persistent_keyring_register);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	if (IS_ERR(persistent))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 		return ERR_CAST(persistent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	return make_key_ref(persistent, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70)  * Get the persistent keyring for a specific UID and link it to the nominated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)  * keyring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) static long key_get_persistent(struct user_namespace *ns, kuid_t uid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 			       key_ref_t dest_ref)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	struct keyring_index_key index_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	struct key *persistent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	key_ref_t reg_ref, persistent_ref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	char buf[32];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	/* Look in the register if it exists */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	memset(&index_key, 0, sizeof(index_key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	index_key.type = &key_type_keyring;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	index_key.description = buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	key_set_index_key(&index_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	if (ns->persistent_keyring_register) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		reg_ref = make_key_ref(ns->persistent_keyring_register, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		down_read(&ns->keyring_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		persistent_ref = find_key_to_update(reg_ref, &index_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		up_read(&ns->keyring_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		if (persistent_ref)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			goto found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	/* It wasn't in the register, so we'll need to create it.  We might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	 * also need to create the register.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	down_write(&ns->keyring_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	persistent_ref = key_create_persistent(ns, uid, &index_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	up_write(&ns->keyring_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	if (!IS_ERR(persistent_ref))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		goto found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	return PTR_ERR(persistent_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	if (ret == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		persistent = key_ref_to_ptr(persistent_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		ret = key_link(key_ref_to_ptr(dest_ref), persistent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		if (ret == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			key_set_timeout(persistent, persistent_keyring_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 			ret = persistent->serial;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	key_ref_put(persistent_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)  * Get the persistent keyring for a specific UID and link it to the nominated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  * keyring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) long keyctl_get_persistent(uid_t _uid, key_serial_t destid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	struct user_namespace *ns = current_user_ns();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	key_ref_t dest_ref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	kuid_t uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	/* -1 indicates the current user */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	if (_uid == (uid_t)-1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		uid = current_uid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		uid = make_kuid(ns, _uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		if (!uid_valid(uid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		/* You can only see your own persistent cache if you're not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		 * sufficiently privileged.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		if (!uid_eq(uid, current_uid()) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		    !uid_eq(uid, current_euid()) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		    !ns_capable(ns, CAP_SETUID))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 			return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	/* There must be a destination keyring */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	if (IS_ERR(dest_ref))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		return PTR_ERR(dest_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 		ret = -ENOTDIR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		goto out_put_dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	ret = key_get_persistent(ns, uid, dest_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) out_put_dest:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	key_ref_put(dest_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }