[mirror_ubuntu-eoan-kernel.git] / security / keys / proc.c

/* procfs files for key database enumeration
 *
 * Copyright (C) 2004 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/init.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/errno.h>
#include "internal.h"

static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
static void proc_keys_stop(struct seq_file *p, void *v);
static int proc_keys_show(struct seq_file *m, void *v);

static const struct seq_operations proc_keys_ops = {
	.start	= proc_keys_start,
	.next	= proc_keys_next,
	.stop	= proc_keys_stop,
	.show	= proc_keys_show,
};

static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
static void proc_key_users_stop(struct seq_file *p, void *v);
static int proc_key_users_show(struct seq_file *m, void *v);

static const struct seq_operations proc_key_users_ops = {
	.start	= proc_key_users_start,
	.next	= proc_key_users_next,
	.stop	= proc_key_users_stop,
	.show	= proc_key_users_show,
};

/*
 * Declare the /proc files.
 */
static int __init key_proc_init(void)
{
	struct proc_dir_entry *p;

	p = proc_create_seq("keys", 0, NULL, &proc_keys_ops);
	if (!p)
		panic("Cannot create /proc/keys\n");

	p = proc_create_seq("key-users", 0, NULL, &proc_key_users_ops);
	if (!p)
		panic("Cannot create /proc/key-users\n");

	return 0;
}

__initcall(key_proc_init);

/*
 * Implement "/proc/keys" to provide a list of the keys on the system that
 * grant View permission to the caller.
 */
static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n)
{
	struct user_namespace *user_ns = seq_user_ns(p);

	n = rb_next(n);
	while (n) {
		struct key *key = rb_entry(n, struct key, serial_node);
		if (kuid_has_mapping(user_ns, key->user->uid))
			break;
		n = rb_next(n);
	}
	return n;
}

static struct key *find_ge_key(struct seq_file *p, key_serial_t id)
{
	struct user_namespace *user_ns = seq_user_ns(p);
	struct rb_node *n = key_serial_tree.rb_node;
	struct key *minkey = NULL;

	while (n) {
		struct key *key = rb_entry(n, struct key, serial_node);
		if (id < key->serial) {
			if (!minkey || minkey->serial > key->serial)
				minkey = key;
			n = n->rb_left;
		} else if (id > key->serial) {
			n = n->rb_right;
		} else {
			minkey = key;
			break;
		}
		key = NULL;
	}

	if (!minkey)
		return NULL;

	for (;;) {
		if (kuid_has_mapping(user_ns, minkey->user->uid))
			return minkey;
		n = rb_next(&minkey->serial_node);
		if (!n)
			return NULL;
		minkey = rb_entry(n, struct key, serial_node);
	}
}

static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
	__acquires(key_serial_lock)
{
	key_serial_t pos = *_pos;
	struct key *key;

	spin_lock(&key_serial_lock);

	if (*_pos > INT_MAX)
		return NULL;
	key = find_ge_key(p, pos);
	if (!key)
		return NULL;
	*_pos = key->serial;
	return &key->serial_node;
}

static inline key_serial_t key_node_serial(struct rb_node *n)
{
	struct key *key = rb_entry(n, struct key, serial_node);
	return key->serial;
}

static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
{
	struct rb_node *n;

	n = key_serial_next(p, v);
	if (n)
		*_pos = key_node_serial(n);
	return n;
}

static void proc_keys_stop(struct seq_file *p, void *v)
	__releases(key_serial_lock)
{
	spin_unlock(&key_serial_lock);
}

static int proc_keys_show(struct seq_file *m, void *v)
{
	struct rb_node *_p = v;
	struct key *key = rb_entry(_p, struct key, serial_node);
	unsigned long flags;
	key_ref_t key_ref, skey_ref;
	time64_t now, expiry;
	char xbuf[16];
	short state;
	u64 timo;
	int rc;

	struct keyring_search_context ctx = {
		.index_key.type		= key->type,
		.index_key.description	= key->description,
		.cred			= m->file->f_cred,
		.match_data.cmp		= lookup_user_key_possessed,
		.match_data.raw_data	= key,
		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
		.flags			= KEYRING_SEARCH_NO_STATE_CHECK,
	};

	key_ref = make_key_ref(key, 0);

	/* determine if the key is possessed by this process (a test we can
	 * skip if the key does not indicate the possessor can view it
	 */
	if (key->perm & KEY_POS_VIEW) {
		skey_ref = search_my_process_keyrings(&ctx);
		if (!IS_ERR(skey_ref)) {
			key_ref_put(skey_ref);
			key_ref = make_key_ref(key, 1);
		}
	}

	/* check whether the current task is allowed to view the key */
	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
	if (rc < 0)
		return 0;

	now = ktime_get_real_seconds();

	rcu_read_lock();

	/* come up with a suitable timeout value */
	expiry = READ_ONCE(key->expiry);
	if (expiry == 0) {
		memcpy(xbuf, "perm", 5);
	} else if (now >= expiry) {
		memcpy(xbuf, "expd", 5);
	} else {
		timo = expiry - now;

		if (timo < 60)
			sprintf(xbuf, "%llus", timo);
		else if (timo < 60*60)
			sprintf(xbuf, "%llum", div_u64(timo, 60));
		else if (timo < 60*60*24)
			sprintf(xbuf, "%lluh", div_u64(timo, 60 * 60));
		else if (timo < 60*60*24*7)
			sprintf(xbuf, "%llud", div_u64(timo, 60 * 60 * 24));
		else
			sprintf(xbuf, "%lluw", div_u64(timo, 60 * 60 * 24 * 7));
	}

	state = key_read_state(key);

#define showflag(FLAGS, LETTER, FLAG) \
	((FLAGS & (1 << FLAG)) ? LETTER : '-')

	flags = READ_ONCE(key->flags);
	seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
		   key->serial,
		   state != KEY_IS_UNINSTANTIATED ? 'I' : '-',
		   showflag(flags, 'R', KEY_FLAG_REVOKED),
		   showflag(flags, 'D', KEY_FLAG_DEAD),
		   showflag(flags, 'Q', KEY_FLAG_IN_QUOTA),
		   showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT),
		   state < 0 ? 'N' : '-',
		   showflag(flags, 'i', KEY_FLAG_INVALIDATED),
		   refcount_read(&key->usage),
		   xbuf,
		   key->perm,
		   from_kuid_munged(seq_user_ns(m), key->uid),
		   from_kgid_munged(seq_user_ns(m), key->gid),
		   key->type->name);

#undef showflag

	if (key->type->describe)
		key->type->describe(key, m);
	seq_putc(m, '\n');

	rcu_read_unlock();
	return 0;
}

static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n)
{
	while (n) {
		struct key_user *user = rb_entry(n, struct key_user, node);
		if (kuid_has_mapping(user_ns, user->uid))
			break;
		n = rb_next(n);
	}
	return n;
}

static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n)
{
	return __key_user_next(user_ns, rb_next(n));
}

static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r)
{
	struct rb_node *n = rb_first(r);
	return __key_user_next(user_ns, n);
}

static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
	__acquires(key_user_lock)
{
	struct rb_node *_p;
	loff_t pos = *_pos;

	spin_lock(&key_user_lock);

	_p = key_user_first(seq_user_ns(p), &key_user_tree);
	while (pos > 0 && _p) {
		pos--;
		_p = key_user_next(seq_user_ns(p), _p);
	}

	return _p;
}

static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
{
	(*_pos)++;
	return key_user_next(seq_user_ns(p), (struct rb_node *)v);
}

static void proc_key_users_stop(struct seq_file *p, void *v)
	__releases(key_user_lock)
{
	spin_unlock(&key_user_lock);
}

static int proc_key_users_show(struct seq_file *m, void *v)
{
	struct rb_node *_p = v;
	struct key_user *user = rb_entry(_p, struct key_user, node);
	unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
		key_quota_root_maxkeys : key_quota_maxkeys;
	unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
		key_quota_root_maxbytes : key_quota_maxbytes;

	seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
		   from_kuid_munged(seq_user_ns(m), user->uid),
		   refcount_read(&user->usage),
		   atomic_read(&user->nkeys),
		   atomic_read(&user->nikeys),
		   user->qnkeys,
		   maxkeys,
		   user->qnbytes,
		   maxbytes);

	return 0;
}
Commit	Line	Data
973c9f4f	1	/* procfs files for key database enumeration
1da177e4 LT	2	*
	3	* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/init.h>
	14	#include <linux/sched.h>
1da177e4 LT	15	#include <linux/fs.h>
	16	#include <linux/proc_fs.h>
	17	#include <linux/seq_file.h>
	18	#include <asm/errno.h>
	19	#include "internal.h"
	20
1da177e4 LT	21	static void proc_keys_start(struct seq_file p, loff_t *_pos);
	22	static void proc_keys_next(struct seq_file p, void v, loff_t _pos);
	23	static void proc_keys_stop(struct seq_file p, void v);
	24	static int proc_keys_show(struct seq_file m, void v);
	25
1996a109	26	static const struct seq_operations proc_keys_ops = {
1da177e4 LT	27	.start = proc_keys_start,
	28	.next = proc_keys_next,
	29	.stop = proc_keys_stop,
	30	.show = proc_keys_show,
	31	};
	32
1da177e4 LT	33	static void proc_key_users_start(struct seq_file p, loff_t *_pos);
	34	static void proc_key_users_next(struct seq_file p, void v, loff_t _pos);
	35	static void proc_key_users_stop(struct seq_file p, void v);
	36	static int proc_key_users_show(struct seq_file m, void v);
	37
1996a109	38	static const struct seq_operations proc_key_users_ops = {
1da177e4 LT	39	.start = proc_key_users_start,
	40	.next = proc_key_users_next,
	41	.stop = proc_key_users_stop,
	42	.show = proc_key_users_show,
	43	};
	44
1da177e4	45	/*
973c9f4f	46	* Declare the /proc files.
1da177e4 LT	47	*/
	48	static int __init key_proc_init(void)
	49	{
	50	struct proc_dir_entry *p;
	51
fddda2b7	52	p = proc_create_seq("keys", 0, NULL, &proc_keys_ops);
1da177e4 LT	53	if (!p)
1da177e4 LT	54	panic("Cannot create /proc/keys\n");
1da177e4	55
fddda2b7	56	p = proc_create_seq("key-users", 0, NULL, &proc_key_users_ops);
1da177e4 LT	57	if (!p)
	58	panic("Cannot create /proc/key-users\n");
	59
1da177e4	60	return 0;
a8b17ed0	61	}
1da177e4 LT	62
	63	__initcall(key_proc_init);
	64
1da177e4	65	/*
973c9f4f DH	66	* Implement "/proc/keys" to provide a list of the keys on the system that
973c9f4f DH	67	* grant View permission to the caller.
1da177e4	68	*/
9a56c2db	69	static struct rb_node key_serial_next(struct seq_file p, struct rb_node *n)
454804ab	70	{
9a56c2db	71	struct user_namespace *user_ns = seq_user_ns(p);
ad73a717 SH	72
ad73a717 SH	73	n = rb_next(n);
454804ab SH	74	while (n) {
454804ab SH	75	struct key *key = rb_entry(n, struct key, serial_node);
9a56c2db	76	if (kuid_has_mapping(user_ns, key->user->uid))
454804ab SH	77	break;
	78	n = rb_next(n);
	79	}
	80	return n;
	81	}
	82
9a56c2db	83	static struct key find_ge_key(struct seq_file p, key_serial_t id)
454804ab	84	{
9a56c2db	85	struct user_namespace *user_ns = seq_user_ns(p);
ad73a717 SH	86	struct rb_node *n = key_serial_tree.rb_node;
ad73a717 SH	87	struct key *minkey = NULL;
454804ab	88
ad73a717 SH	89	while (n) {
	90	struct key *key = rb_entry(n, struct key, serial_node);
	91	if (id < key->serial) {
	92	if (!minkey \|\| minkey->serial > key->serial)
	93	minkey = key;
	94	n = n->rb_left;
	95	} else if (id > key->serial) {
	96	n = n->rb_right;
	97	} else {
	98	minkey = key;
	99	break;
	100	}
	101	key = NULL;
	102	}
1da177e4	103
ad73a717 SH	104	if (!minkey)
	105	return NULL;
	106
	107	for (;;) {
9a56c2db	108	if (kuid_has_mapping(user_ns, minkey->user->uid))
ad73a717 SH	109	return minkey;
	110	n = rb_next(&minkey->serial_node);
	111	if (!n)
	112	return NULL;
	113	minkey = rb_entry(n, struct key, serial_node);
	114	}
1da177e4 LT	115	}
	116
	117	static void proc_keys_start(struct seq_file p, loff_t *_pos)
86abcf9c	118	__acquires(key_serial_lock)
1da177e4	119	{
ad73a717 SH	120	key_serial_t pos = *_pos;
ad73a717 SH	121	struct key *key;
1da177e4 LT	122
	123	spin_lock(&key_serial_lock);
	124
ad73a717 SH	125	if (*_pos > INT_MAX)
ad73a717 SH	126	return NULL;
9a56c2db	127	key = find_ge_key(p, pos);
ad73a717 SH	128	if (!key)
	129	return NULL;
	130	*_pos = key->serial;
	131	return &key->serial_node;
	132	}
1da177e4	133
ad73a717 SH	134	static inline key_serial_t key_node_serial(struct rb_node *n)
	135	{
	136	struct key *key = rb_entry(n, struct key, serial_node);
	137	return key->serial;
1da177e4 LT	138	}
	139
	140	static void proc_keys_next(struct seq_file p, void v, loff_t _pos)
	141	{
ad73a717	142	struct rb_node *n;
1da177e4	143
9a56c2db	144	n = key_serial_next(p, v);
ad73a717 SH	145	if (n)
	146	*_pos = key_node_serial(n);
	147	return n;
1da177e4 LT	148	}
	149
	150	static void proc_keys_stop(struct seq_file p, void v)
86abcf9c	151	__releases(key_serial_lock)
1da177e4 LT	152	{
	153	spin_unlock(&key_serial_lock);
	154	}
	155
	156	static int proc_keys_show(struct seq_file m, void v)
	157	{
	158	struct rb_node *_p = v;
	159	struct key *key = rb_entry(_p, struct key, serial_node);
ab5c69f0	160	unsigned long flags;
927942aa	161	key_ref_t key_ref, skey_ref;
074d5898	162	time64_t now, expiry;
03dab869	163	char xbuf[16];
363b02da	164	short state;
074d5898	165	u64 timo;
06ec7be5 ML	166	int rc;
06ec7be5 ML	167
4bdf0bc3 DH	168	struct keyring_search_context ctx = {
	169	.index_key.type = key->type,
	170	.index_key.description = key->description,
4aa68e07	171	.cred = m->file->f_cred,
46291959 DH	172	.match_data.cmp = lookup_user_key_possessed,
	173	.match_data.raw_data = key,
	174	.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
	175	.flags = KEYRING_SEARCH_NO_STATE_CHECK,
4bdf0bc3 DH	176	};
4bdf0bc3 DH	177
927942aa DH	178	key_ref = make_key_ref(key, 0);
	179
	180	/* determine if the key is possessed by this process (a test we can
	181	* skip if the key does not indicate the possessor can view it
	182	*/
	183	if (key->perm & KEY_POS_VIEW) {
4bdf0bc3	184	skey_ref = search_my_process_keyrings(&ctx);
927942aa DH	185	if (!IS_ERR(skey_ref)) {
	186	key_ref_put(skey_ref);
	187	key_ref = make_key_ref(key, 1);
	188	}
	189	}
	190
4aa68e07	191	/* check whether the current task is allowed to view the key */
f5895943	192	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
06ec7be5 ML	193	if (rc < 0)
06ec7be5 ML	194	return 0;
1da177e4	195
074d5898	196	now = ktime_get_real_seconds();
1da177e4	197
76d8aeab	198	rcu_read_lock();
1da177e4 LT	199
1da177e4 LT	200	/* come up with a suitable timeout value */
ab5c69f0 EB	201	expiry = READ_ONCE(key->expiry);
ab5c69f0 EB	202	if (expiry == 0) {
1da177e4	203	memcpy(xbuf, "perm", 5);
074d5898	204	} else if (now >= expiry) {
1da177e4	205	memcpy(xbuf, "expd", 5);
7b1b9164	206	} else {
074d5898	207	timo = expiry - now;
1da177e4 LT	208
1da177e4 LT	209	if (timo < 60)
074d5898	210	sprintf(xbuf, "%llus", timo);
1da177e4	211	else if (timo < 60*60)
074d5898	212	sprintf(xbuf, "%llum", div_u64(timo, 60));
1da177e4	213	else if (timo < 606024)
074d5898	214	sprintf(xbuf, "%lluh", div_u64(timo, 60 * 60));
1da177e4	215	else if (timo < 606024*7)
074d5898	216	sprintf(xbuf, "%llud", div_u64(timo, 60 * 60 * 24));
1da177e4	217	else
074d5898	218	sprintf(xbuf, "%lluw", div_u64(timo, 60 * 60 * 24 * 7));
1da177e4 LT	219	}
1da177e4 LT	220
363b02da DH	221	state = key_read_state(key);
363b02da DH	222
ab5c69f0 EB	223	#define showflag(FLAGS, LETTER, FLAG) \
ab5c69f0 EB	224	((FLAGS & (1 << FLAG)) ? LETTER : '-')
76d8aeab	225
ab5c69f0	226	flags = READ_ONCE(key->flags);
fd75815f	227	seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
1da177e4	228	key->serial,
363b02da	229	state != KEY_IS_UNINSTANTIATED ? 'I' : '-',
ab5c69f0 EB	230	showflag(flags, 'R', KEY_FLAG_REVOKED),
	231	showflag(flags, 'D', KEY_FLAG_DEAD),
	232	showflag(flags, 'Q', KEY_FLAG_IN_QUOTA),
	233	showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT),
363b02da	234	state < 0 ? 'N' : '-',
ab5c69f0	235	showflag(flags, 'i', KEY_FLAG_INVALIDATED),
fff29291	236	refcount_read(&key->usage),
1da177e4 LT	237	xbuf,
1da177e4 LT	238	key->perm,
9a56c2db EB	239	from_kuid_munged(seq_user_ns(m), key->uid),
9a56c2db EB	240	from_kgid_munged(seq_user_ns(m), key->gid),
1da177e4 LT	241	key->type->name);
1da177e4 LT	242
76d8aeab DH	243	#undef showflag
76d8aeab DH	244
1da177e4 LT	245	if (key->type->describe)
	246	key->type->describe(key, m);
	247	seq_putc(m, '\n');
	248
76d8aeab	249	rcu_read_unlock();
1da177e4	250	return 0;
1da177e4 LT	251	}
1da177e4 LT	252
9a56c2db	253	static struct rb_node __key_user_next(struct user_namespace user_ns, struct rb_node *n)
454804ab SH	254	{
	255	while (n) {
	256	struct key_user *user = rb_entry(n, struct key_user, node);
9a56c2db	257	if (kuid_has_mapping(user_ns, user->uid))
454804ab SH	258	break;
	259	n = rb_next(n);
	260	}
	261	return n;
	262	}
	263
9a56c2db	264	static struct rb_node key_user_next(struct user_namespace user_ns, struct rb_node *n)
454804ab	265	{
9a56c2db	266	return __key_user_next(user_ns, rb_next(n));
454804ab SH	267	}
454804ab SH	268
9a56c2db	269	static struct rb_node key_user_first(struct user_namespace user_ns, struct rb_root *r)
454804ab SH	270	{
454804ab SH	271	struct rb_node *n = rb_first(r);
9a56c2db	272	return __key_user_next(user_ns, n);
454804ab	273	}
7b1b9164	274
1da177e4	275	static void proc_key_users_start(struct seq_file p, loff_t *_pos)
86abcf9c	276	__acquires(key_user_lock)
1da177e4 LT	277	{
	278	struct rb_node *_p;
	279	loff_t pos = *_pos;
	280
	281	spin_lock(&key_user_lock);
	282
9a56c2db	283	_p = key_user_first(seq_user_ns(p), &key_user_tree);
1da177e4 LT	284	while (pos > 0 && _p) {
1da177e4 LT	285	pos--;
9a56c2db	286	_p = key_user_next(seq_user_ns(p), _p);
1da177e4 LT	287	}
	288
	289	return _p;
1da177e4 LT	290	}
	291
	292	static void proc_key_users_next(struct seq_file p, void v, loff_t _pos)
	293	{
	294	(*_pos)++;
9a56c2db	295	return key_user_next(seq_user_ns(p), (struct rb_node *)v);
1da177e4 LT	296	}
	297
	298	static void proc_key_users_stop(struct seq_file p, void v)
86abcf9c	299	__releases(key_user_lock)
1da177e4 LT	300	{
	301	spin_unlock(&key_user_lock);
	302	}
	303
	304	static int proc_key_users_show(struct seq_file m, void v)
	305	{
	306	struct rb_node *_p = v;
	307	struct key_user *user = rb_entry(_p, struct key_user, node);
9a56c2db	308	unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
0b77f5bf	309	key_quota_root_maxkeys : key_quota_maxkeys;
9a56c2db	310	unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
0b77f5bf	311	key_quota_root_maxbytes : key_quota_maxbytes;
1da177e4 LT	312
1da177e4 LT	313	seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
9a56c2db	314	from_kuid_munged(seq_user_ns(m), user->uid),
ddb99e11	315	refcount_read(&user->usage),
1da177e4 LT	316	atomic_read(&user->nkeys),
	317	atomic_read(&user->nikeys),
	318	user->qnkeys,
0b77f5bf	319	maxkeys,
1da177e4	320	user->qnbytes,
0b77f5bf	321	maxbytes);
1da177e4 LT	322
1da177e4 LT	323	return 0;
1da177e4	324	}