[linux.git] / security / keys / proc.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* procfs files for key database enumeration
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#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		= key->index_key,
		.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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
973c9f4f	2	/* procfs files for key database enumeration
1da177e4 LT	3	*
	4	* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells ([email protected])
1da177e4 LT	6	*/
1da177e4 LT	7
1da177e4 LT	8	#include <linux/init.h>
1da177e4 LT	9	#include <linux/sched.h>
1da177e4 LT	10	#include <linux/fs.h>
	11	#include <linux/proc_fs.h>
	12	#include <linux/seq_file.h>
	13	#include <asm/errno.h>
	14	#include "internal.h"
	15
1da177e4 LT	16	static void proc_keys_start(struct seq_file p, loff_t *_pos);
	17	static void proc_keys_next(struct seq_file p, void v, loff_t _pos);
	18	static void proc_keys_stop(struct seq_file p, void v);
	19	static int proc_keys_show(struct seq_file m, void v);
	20
1996a109	21	static const struct seq_operations proc_keys_ops = {
1da177e4 LT	22	.start = proc_keys_start,
	23	.next = proc_keys_next,
	24	.stop = proc_keys_stop,
	25	.show = proc_keys_show,
	26	};
	27
1da177e4 LT	28	static void proc_key_users_start(struct seq_file p, loff_t *_pos);
	29	static void proc_key_users_next(struct seq_file p, void v, loff_t _pos);
	30	static void proc_key_users_stop(struct seq_file p, void v);
	31	static int proc_key_users_show(struct seq_file m, void v);
	32
1996a109	33	static const struct seq_operations proc_key_users_ops = {
1da177e4 LT	34	.start = proc_key_users_start,
	35	.next = proc_key_users_next,
	36	.stop = proc_key_users_stop,
	37	.show = proc_key_users_show,
	38	};
	39
1da177e4	40	/*
973c9f4f	41	* Declare the /proc files.
1da177e4 LT	42	*/
	43	static int __init key_proc_init(void)
	44	{
	45	struct proc_dir_entry *p;
	46
fddda2b7	47	p = proc_create_seq("keys", 0, NULL, &proc_keys_ops);
1da177e4 LT	48	if (!p)
1da177e4 LT	49	panic("Cannot create /proc/keys\n");
1da177e4	50
fddda2b7	51	p = proc_create_seq("key-users", 0, NULL, &proc_key_users_ops);
1da177e4 LT	52	if (!p)
	53	panic("Cannot create /proc/key-users\n");
	54
1da177e4	55	return 0;
a8b17ed0	56	}
1da177e4 LT	57
	58	__initcall(key_proc_init);
	59
1da177e4	60	/*
973c9f4f DH	61	* Implement "/proc/keys" to provide a list of the keys on the system that
973c9f4f DH	62	* grant View permission to the caller.
1da177e4	63	*/
9a56c2db	64	static struct rb_node key_serial_next(struct seq_file p, struct rb_node *n)
454804ab	65	{
9a56c2db	66	struct user_namespace *user_ns = seq_user_ns(p);
ad73a717 SH	67
ad73a717 SH	68	n = rb_next(n);
454804ab SH	69	while (n) {
454804ab SH	70	struct key *key = rb_entry(n, struct key, serial_node);
9a56c2db	71	if (kuid_has_mapping(user_ns, key->user->uid))
454804ab SH	72	break;
	73	n = rb_next(n);
	74	}
	75	return n;
	76	}
	77
9a56c2db	78	static struct key find_ge_key(struct seq_file p, key_serial_t id)
454804ab	79	{
9a56c2db	80	struct user_namespace *user_ns = seq_user_ns(p);
ad73a717 SH	81	struct rb_node *n = key_serial_tree.rb_node;
ad73a717 SH	82	struct key *minkey = NULL;
454804ab	83
ad73a717 SH	84	while (n) {
	85	struct key *key = rb_entry(n, struct key, serial_node);
	86	if (id < key->serial) {
	87	if (!minkey \|\| minkey->serial > key->serial)
	88	minkey = key;
	89	n = n->rb_left;
	90	} else if (id > key->serial) {
	91	n = n->rb_right;
	92	} else {
	93	minkey = key;
	94	break;
	95	}
	96	key = NULL;
	97	}
1da177e4	98
ad73a717 SH	99	if (!minkey)
	100	return NULL;
	101
	102	for (;;) {
9a56c2db	103	if (kuid_has_mapping(user_ns, minkey->user->uid))
ad73a717 SH	104	return minkey;
	105	n = rb_next(&minkey->serial_node);
	106	if (!n)
	107	return NULL;
	108	minkey = rb_entry(n, struct key, serial_node);
	109	}
1da177e4 LT	110	}
	111
	112	static void proc_keys_start(struct seq_file p, loff_t *_pos)
86abcf9c	113	__acquires(key_serial_lock)
1da177e4	114	{
ad73a717 SH	115	key_serial_t pos = *_pos;
ad73a717 SH	116	struct key *key;
1da177e4 LT	117
	118	spin_lock(&key_serial_lock);
	119
ad73a717 SH	120	if (*_pos > INT_MAX)
ad73a717 SH	121	return NULL;
9a56c2db	122	key = find_ge_key(p, pos);
ad73a717 SH	123	if (!key)
	124	return NULL;
	125	*_pos = key->serial;
	126	return &key->serial_node;
	127	}
1da177e4	128
ad73a717 SH	129	static inline key_serial_t key_node_serial(struct rb_node *n)
	130	{
	131	struct key *key = rb_entry(n, struct key, serial_node);
	132	return key->serial;
1da177e4 LT	133	}
	134
	135	static void proc_keys_next(struct seq_file p, void v, loff_t _pos)
	136	{
ad73a717	137	struct rb_node *n;
1da177e4	138
9a56c2db	139	n = key_serial_next(p, v);
ad73a717 SH	140	if (n)
	141	*_pos = key_node_serial(n);
	142	return n;
1da177e4 LT	143	}
	144
	145	static void proc_keys_stop(struct seq_file p, void v)
86abcf9c	146	__releases(key_serial_lock)
1da177e4 LT	147	{
	148	spin_unlock(&key_serial_lock);
	149	}
	150
	151	static int proc_keys_show(struct seq_file m, void v)
	152	{
	153	struct rb_node *_p = v;
	154	struct key *key = rb_entry(_p, struct key, serial_node);
ab5c69f0	155	unsigned long flags;
927942aa	156	key_ref_t key_ref, skey_ref;
074d5898	157	time64_t now, expiry;
03dab869	158	char xbuf[16];
363b02da	159	short state;
074d5898	160	u64 timo;
06ec7be5 ML	161	int rc;
06ec7be5 ML	162
4bdf0bc3	163	struct keyring_search_context ctx = {
ede0fa98	164	.index_key = key->index_key,
4aa68e07	165	.cred = m->file->f_cred,
46291959 DH	166	.match_data.cmp = lookup_user_key_possessed,
	167	.match_data.raw_data = key,
	168	.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
	169	.flags = KEYRING_SEARCH_NO_STATE_CHECK,
4bdf0bc3 DH	170	};
4bdf0bc3 DH	171
927942aa DH	172	key_ref = make_key_ref(key, 0);
	173
	174	/* determine if the key is possessed by this process (a test we can
	175	* skip if the key does not indicate the possessor can view it
	176	*/
	177	if (key->perm & KEY_POS_VIEW) {
4bdf0bc3	178	skey_ref = search_my_process_keyrings(&ctx);
927942aa DH	179	if (!IS_ERR(skey_ref)) {
	180	key_ref_put(skey_ref);
	181	key_ref = make_key_ref(key, 1);
	182	}
	183	}
	184
4aa68e07	185	/* check whether the current task is allowed to view the key */
f5895943	186	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
06ec7be5 ML	187	if (rc < 0)
06ec7be5 ML	188	return 0;
1da177e4	189
074d5898	190	now = ktime_get_real_seconds();
1da177e4	191
76d8aeab	192	rcu_read_lock();
1da177e4 LT	193
1da177e4 LT	194	/* come up with a suitable timeout value */
ab5c69f0 EB	195	expiry = READ_ONCE(key->expiry);
ab5c69f0 EB	196	if (expiry == 0) {
1da177e4	197	memcpy(xbuf, "perm", 5);
074d5898	198	} else if (now >= expiry) {
1da177e4	199	memcpy(xbuf, "expd", 5);
7b1b9164	200	} else {
074d5898	201	timo = expiry - now;
1da177e4 LT	202
1da177e4 LT	203	if (timo < 60)
074d5898	204	sprintf(xbuf, "%llus", timo);
1da177e4	205	else if (timo < 60*60)
074d5898	206	sprintf(xbuf, "%llum", div_u64(timo, 60));
1da177e4	207	else if (timo < 606024)
074d5898	208	sprintf(xbuf, "%lluh", div_u64(timo, 60 * 60));
1da177e4	209	else if (timo < 606024*7)
074d5898	210	sprintf(xbuf, "%llud", div_u64(timo, 60 * 60 * 24));
1da177e4	211	else
074d5898	212	sprintf(xbuf, "%lluw", div_u64(timo, 60 * 60 * 24 * 7));
1da177e4 LT	213	}
1da177e4 LT	214
363b02da DH	215	state = key_read_state(key);
363b02da DH	216
ab5c69f0 EB	217	#define showflag(FLAGS, LETTER, FLAG) \
ab5c69f0 EB	218	((FLAGS & (1 << FLAG)) ? LETTER : '-')
76d8aeab	219
ab5c69f0	220	flags = READ_ONCE(key->flags);
fd75815f	221	seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
1da177e4	222	key->serial,
363b02da	223	state != KEY_IS_UNINSTANTIATED ? 'I' : '-',
ab5c69f0 EB	224	showflag(flags, 'R', KEY_FLAG_REVOKED),
	225	showflag(flags, 'D', KEY_FLAG_DEAD),
	226	showflag(flags, 'Q', KEY_FLAG_IN_QUOTA),
	227	showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT),
363b02da	228	state < 0 ? 'N' : '-',
ab5c69f0	229	showflag(flags, 'i', KEY_FLAG_INVALIDATED),
fff29291	230	refcount_read(&key->usage),
1da177e4 LT	231	xbuf,
1da177e4 LT	232	key->perm,
9a56c2db EB	233	from_kuid_munged(seq_user_ns(m), key->uid),
9a56c2db EB	234	from_kgid_munged(seq_user_ns(m), key->gid),
1da177e4 LT	235	key->type->name);
1da177e4 LT	236
76d8aeab DH	237	#undef showflag
76d8aeab DH	238
1da177e4 LT	239	if (key->type->describe)
	240	key->type->describe(key, m);
	241	seq_putc(m, '\n');
	242
76d8aeab	243	rcu_read_unlock();
1da177e4	244	return 0;
1da177e4 LT	245	}
1da177e4 LT	246
9a56c2db	247	static struct rb_node __key_user_next(struct user_namespace user_ns, struct rb_node *n)
454804ab SH	248	{
	249	while (n) {
	250	struct key_user *user = rb_entry(n, struct key_user, node);
9a56c2db	251	if (kuid_has_mapping(user_ns, user->uid))
454804ab SH	252	break;
	253	n = rb_next(n);
	254	}
	255	return n;
	256	}
	257
9a56c2db	258	static struct rb_node key_user_next(struct user_namespace user_ns, struct rb_node *n)
454804ab	259	{
9a56c2db	260	return __key_user_next(user_ns, rb_next(n));
454804ab SH	261	}
454804ab SH	262
9a56c2db	263	static struct rb_node key_user_first(struct user_namespace user_ns, struct rb_root *r)
454804ab SH	264	{
454804ab SH	265	struct rb_node *n = rb_first(r);
9a56c2db	266	return __key_user_next(user_ns, n);
454804ab	267	}
7b1b9164	268
1da177e4	269	static void proc_key_users_start(struct seq_file p, loff_t *_pos)
86abcf9c	270	__acquires(key_user_lock)
1da177e4 LT	271	{
	272	struct rb_node *_p;
	273	loff_t pos = *_pos;
	274
	275	spin_lock(&key_user_lock);
	276
9a56c2db	277	_p = key_user_first(seq_user_ns(p), &key_user_tree);
1da177e4 LT	278	while (pos > 0 && _p) {
1da177e4 LT	279	pos--;
9a56c2db	280	_p = key_user_next(seq_user_ns(p), _p);
1da177e4 LT	281	}
	282
	283	return _p;
1da177e4 LT	284	}
	285
	286	static void proc_key_users_next(struct seq_file p, void v, loff_t _pos)
	287	{
	288	(*_pos)++;
9a56c2db	289	return key_user_next(seq_user_ns(p), (struct rb_node *)v);
1da177e4 LT	290	}
	291
	292	static void proc_key_users_stop(struct seq_file p, void v)
86abcf9c	293	__releases(key_user_lock)
1da177e4 LT	294	{
	295	spin_unlock(&key_user_lock);
	296	}
	297
	298	static int proc_key_users_show(struct seq_file m, void v)
	299	{
	300	struct rb_node *_p = v;
	301	struct key_user *user = rb_entry(_p, struct key_user, node);
9a56c2db	302	unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
0b77f5bf	303	key_quota_root_maxkeys : key_quota_maxkeys;
9a56c2db	304	unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
0b77f5bf	305	key_quota_root_maxbytes : key_quota_maxbytes;
1da177e4 LT	306
1da177e4 LT	307	seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
9a56c2db	308	from_kuid_munged(seq_user_ns(m), user->uid),
ddb99e11	309	refcount_read(&user->usage),
1da177e4 LT	310	atomic_read(&user->nkeys),
	311	atomic_read(&user->nikeys),
	312	user->qnkeys,
0b77f5bf	313	maxkeys,
1da177e4	314	user->qnbytes,
0b77f5bf	315	maxbytes);
1da177e4 LT	316
1da177e4 LT	317	return 0;
1da177e4	318	}