2011-01-21 00:38:33 +08:00
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/* procfs files for key database enumeration
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2005-04-17 06:20:36 +08:00
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <asm/errno.h>
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#include "internal.h"
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static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
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static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
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static void proc_keys_stop(struct seq_file *p, void *v);
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static int proc_keys_show(struct seq_file *m, void *v);
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2008-01-23 07:02:58 +08:00
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static const struct seq_operations proc_keys_ops = {
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2005-04-17 06:20:36 +08:00
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.start = proc_keys_start,
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.next = proc_keys_next,
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.stop = proc_keys_stop,
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.show = proc_keys_show,
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};
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static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
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static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
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static void proc_key_users_stop(struct seq_file *p, void *v);
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static int proc_key_users_show(struct seq_file *m, void *v);
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2008-01-23 07:02:58 +08:00
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static const struct seq_operations proc_key_users_ops = {
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2005-04-17 06:20:36 +08:00
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.start = proc_key_users_start,
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.next = proc_key_users_next,
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.stop = proc_key_users_stop,
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.show = proc_key_users_show,
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};
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/*
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2011-01-21 00:38:33 +08:00
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* Declare the /proc files.
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2005-04-17 06:20:36 +08:00
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*/
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static int __init key_proc_init(void)
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{
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struct proc_dir_entry *p;
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2018-04-14 01:44:18 +08:00
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p = proc_create_seq("keys", 0, NULL, &proc_keys_ops);
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2005-04-17 06:20:36 +08:00
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if (!p)
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panic("Cannot create /proc/keys\n");
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2018-04-14 01:44:18 +08:00
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p = proc_create_seq("key-users", 0, NULL, &proc_key_users_ops);
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2005-04-17 06:20:36 +08:00
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if (!p)
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panic("Cannot create /proc/key-users\n");
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return 0;
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2011-01-21 00:38:27 +08:00
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}
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2005-04-17 06:20:36 +08:00
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__initcall(key_proc_init);
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/*
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2011-01-21 00:38:33 +08:00
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* Implement "/proc/keys" to provide a list of the keys on the system that
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* grant View permission to the caller.
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2005-04-17 06:20:36 +08:00
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*/
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2012-02-08 23:53:04 +08:00
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static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n)
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2009-02-27 08:28:04 +08:00
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{
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2012-02-08 23:53:04 +08:00
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struct user_namespace *user_ns = seq_user_ns(p);
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2009-09-02 16:14:05 +08:00
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n = rb_next(n);
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2009-02-27 08:28:04 +08:00
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while (n) {
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struct key *key = rb_entry(n, struct key, serial_node);
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2012-02-08 23:53:04 +08:00
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if (kuid_has_mapping(user_ns, key->user->uid))
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2009-02-27 08:28:04 +08:00
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break;
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n = rb_next(n);
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}
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return n;
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}
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2012-02-08 23:53:04 +08:00
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static struct key *find_ge_key(struct seq_file *p, key_serial_t id)
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2009-02-27 08:28:04 +08:00
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{
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2012-02-08 23:53:04 +08:00
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struct user_namespace *user_ns = seq_user_ns(p);
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2009-09-02 16:14:05 +08:00
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struct rb_node *n = key_serial_tree.rb_node;
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struct key *minkey = NULL;
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2009-02-27 08:28:04 +08:00
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2009-09-02 16:14:05 +08:00
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while (n) {
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struct key *key = rb_entry(n, struct key, serial_node);
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if (id < key->serial) {
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if (!minkey || minkey->serial > key->serial)
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minkey = key;
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n = n->rb_left;
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} else if (id > key->serial) {
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n = n->rb_right;
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} else {
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minkey = key;
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break;
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}
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key = NULL;
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}
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2005-04-17 06:20:36 +08:00
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2009-09-02 16:14:05 +08:00
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if (!minkey)
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return NULL;
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for (;;) {
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2012-02-08 23:53:04 +08:00
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if (kuid_has_mapping(user_ns, minkey->user->uid))
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2009-09-02 16:14:05 +08:00
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return minkey;
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n = rb_next(&minkey->serial_node);
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if (!n)
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return NULL;
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minkey = rb_entry(n, struct key, serial_node);
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}
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2005-04-17 06:20:36 +08:00
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}
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static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
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2009-06-18 20:00:05 +08:00
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__acquires(key_serial_lock)
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2005-04-17 06:20:36 +08:00
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{
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2009-09-02 16:14:05 +08:00
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key_serial_t pos = *_pos;
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struct key *key;
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2005-04-17 06:20:36 +08:00
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spin_lock(&key_serial_lock);
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2009-09-02 16:14:05 +08:00
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if (*_pos > INT_MAX)
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return NULL;
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2012-02-08 23:53:04 +08:00
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key = find_ge_key(p, pos);
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2009-09-02 16:14:05 +08:00
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if (!key)
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return NULL;
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*_pos = key->serial;
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return &key->serial_node;
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}
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2005-04-17 06:20:36 +08:00
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2009-09-02 16:14:05 +08:00
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static inline key_serial_t key_node_serial(struct rb_node *n)
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{
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struct key *key = rb_entry(n, struct key, serial_node);
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return key->serial;
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2005-04-17 06:20:36 +08:00
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}
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static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
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{
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2009-09-02 16:14:05 +08:00
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struct rb_node *n;
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2005-04-17 06:20:36 +08:00
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2012-02-08 23:53:04 +08:00
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n = key_serial_next(p, v);
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2009-09-02 16:14:05 +08:00
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if (n)
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*_pos = key_node_serial(n);
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return n;
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2005-04-17 06:20:36 +08:00
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}
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static void proc_keys_stop(struct seq_file *p, void *v)
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2009-06-18 20:00:05 +08:00
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__releases(key_serial_lock)
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2005-04-17 06:20:36 +08:00
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{
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spin_unlock(&key_serial_lock);
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}
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static int proc_keys_show(struct seq_file *m, void *v)
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{
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struct rb_node *_p = v;
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struct key *key = rb_entry(_p, struct key, serial_node);
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2017-09-28 03:50:46 +08:00
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unsigned long flags;
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2010-06-12 00:31:10 +08:00
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key_ref_t key_ref, skey_ref;
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2017-11-16 00:38:45 +08:00
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time64_t now, expiry;
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2016-10-26 22:01:54 +08:00
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char xbuf[16];
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2017-10-04 23:43:25 +08:00
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short state;
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2017-11-16 00:38:45 +08:00
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u64 timo;
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2006-06-26 15:24:56 +08:00
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int rc;
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2013-09-24 17:35:15 +08:00
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struct keyring_search_context ctx = {
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KEYS: always initialize keyring_index_key::desc_len
syzbot hit the 'BUG_ON(index_key->desc_len == 0);' in __key_link_begin()
called from construct_alloc_key() during sys_request_key(), because the
length of the key description was never calculated.
The problem is that we rely on ->desc_len being initialized by
search_process_keyrings(), specifically by search_nested_keyrings().
But, if the process isn't subscribed to any keyrings that never happens.
Fix it by always initializing keyring_index_key::desc_len as soon as the
description is set, like we already do in some places.
The following program reproduces the BUG_ON() when it's run as root and
no session keyring has been installed. If it doesn't work, try removing
pam_keyinit.so from /etc/pam.d/login and rebooting.
#include <stdlib.h>
#include <unistd.h>
#include <keyutils.h>
int main(void)
{
int id = add_key("keyring", "syz", NULL, 0, KEY_SPEC_USER_KEYRING);
keyctl_setperm(id, KEY_OTH_WRITE);
setreuid(5000, 5000);
request_key("user", "desc", "", id);
}
Reported-by: syzbot+ec24e95ea483de0a24da@syzkaller.appspotmail.com
Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.morris@microsoft.com>
2019-02-22 23:36:18 +08:00
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.index_key = key->index_key,
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2017-09-19 02:38:29 +08:00
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.cred = m->file->f_cred,
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2014-09-17 00:36:02 +08:00
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.match_data.cmp = lookup_user_key_possessed,
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.match_data.raw_data = key,
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.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
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.flags = KEYRING_SEARCH_NO_STATE_CHECK,
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2013-09-24 17:35:15 +08:00
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};
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2010-06-12 00:31:10 +08:00
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key_ref = make_key_ref(key, 0);
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/* determine if the key is possessed by this process (a test we can
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* skip if the key does not indicate the possessor can view it
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*/
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if (key->perm & KEY_POS_VIEW) {
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2019-06-19 23:10:15 +08:00
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rcu_read_lock();
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skey_ref = search_cred_keyrings_rcu(&ctx);
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rcu_read_unlock();
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2010-06-12 00:31:10 +08:00
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if (!IS_ERR(skey_ref)) {
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key_ref_put(skey_ref);
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key_ref = make_key_ref(key, 1);
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}
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}
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2017-09-19 02:38:29 +08:00
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/* check whether the current task is allowed to view the key */
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2014-03-15 01:44:49 +08:00
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rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
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2006-06-26 15:24:56 +08:00
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if (rc < 0)
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return 0;
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2005-04-17 06:20:36 +08:00
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2017-11-16 00:38:45 +08:00
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now = ktime_get_real_seconds();
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2005-04-17 06:20:36 +08:00
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2005-06-24 13:00:49 +08:00
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rcu_read_lock();
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2005-04-17 06:20:36 +08:00
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/* come up with a suitable timeout value */
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2017-09-28 03:50:46 +08:00
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expiry = READ_ONCE(key->expiry);
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if (expiry == 0) {
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2005-04-17 06:20:36 +08:00
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memcpy(xbuf, "perm", 5);
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2017-11-16 00:38:45 +08:00
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} else if (now >= expiry) {
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2005-04-17 06:20:36 +08:00
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memcpy(xbuf, "expd", 5);
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2009-09-02 16:14:11 +08:00
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} else {
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2017-11-16 00:38:45 +08:00
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timo = expiry - now;
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2005-04-17 06:20:36 +08:00
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if (timo < 60)
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2017-11-16 00:38:45 +08:00
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sprintf(xbuf, "%llus", timo);
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2005-04-17 06:20:36 +08:00
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else if (timo < 60*60)
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2017-11-16 00:38:45 +08:00
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sprintf(xbuf, "%llum", div_u64(timo, 60));
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2005-04-17 06:20:36 +08:00
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else if (timo < 60*60*24)
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2017-11-16 00:38:45 +08:00
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sprintf(xbuf, "%lluh", div_u64(timo, 60 * 60));
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2005-04-17 06:20:36 +08:00
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else if (timo < 60*60*24*7)
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2017-11-16 00:38:45 +08:00
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sprintf(xbuf, "%llud", div_u64(timo, 60 * 60 * 24));
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2005-04-17 06:20:36 +08:00
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else
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2017-11-16 00:38:45 +08:00
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sprintf(xbuf, "%lluw", div_u64(timo, 60 * 60 * 24 * 7));
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2005-04-17 06:20:36 +08:00
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}
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2017-10-04 23:43:25 +08:00
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state = key_read_state(key);
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2017-09-28 03:50:46 +08:00
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#define showflag(FLAGS, LETTER, FLAG) \
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((FLAGS & (1 << FLAG)) ? LETTER : '-')
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2005-06-24 13:00:49 +08:00
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2017-09-28 03:50:46 +08:00
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flags = READ_ONCE(key->flags);
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2012-05-11 17:56:56 +08:00
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seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
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2005-04-17 06:20:36 +08:00
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key->serial,
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2017-10-04 23:43:25 +08:00
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state != KEY_IS_UNINSTANTIATED ? 'I' : '-',
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2017-09-28 03:50:46 +08:00
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showflag(flags, 'R', KEY_FLAG_REVOKED),
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showflag(flags, 'D', KEY_FLAG_DEAD),
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showflag(flags, 'Q', KEY_FLAG_IN_QUOTA),
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showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT),
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2017-10-04 23:43:25 +08:00
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state < 0 ? 'N' : '-',
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2017-09-28 03:50:46 +08:00
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showflag(flags, 'i', KEY_FLAG_INVALIDATED),
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2017-03-31 20:20:48 +08:00
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refcount_read(&key->usage),
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2005-04-17 06:20:36 +08:00
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xbuf,
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key->perm,
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2012-02-08 23:53:04 +08:00
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from_kuid_munged(seq_user_ns(m), key->uid),
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from_kgid_munged(seq_user_ns(m), key->gid),
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2005-04-17 06:20:36 +08:00
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key->type->name);
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2005-06-24 13:00:49 +08:00
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#undef showflag
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2005-04-17 06:20:36 +08:00
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if (key->type->describe)
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key->type->describe(key, m);
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seq_putc(m, '\n');
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2005-06-24 13:00:49 +08:00
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rcu_read_unlock();
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2005-04-17 06:20:36 +08:00
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return 0;
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}
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2012-02-08 23:53:04 +08:00
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static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n)
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2009-02-27 08:28:04 +08:00
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{
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while (n) {
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struct key_user *user = rb_entry(n, struct key_user, node);
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2012-02-08 23:53:04 +08:00
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if (kuid_has_mapping(user_ns, user->uid))
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2009-02-27 08:28:04 +08:00
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break;
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n = rb_next(n);
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}
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return n;
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}
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2012-02-08 23:53:04 +08:00
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static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n)
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2009-02-27 08:28:04 +08:00
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{
|
2012-02-08 23:53:04 +08:00
|
|
|
return __key_user_next(user_ns, rb_next(n));
|
2009-02-27 08:28:04 +08:00
|
|
|
}
|
|
|
|
|
2012-02-08 23:53:04 +08:00
|
|
|
static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r)
|
2009-02-27 08:28:04 +08:00
|
|
|
{
|
|
|
|
struct rb_node *n = rb_first(r);
|
2012-02-08 23:53:04 +08:00
|
|
|
return __key_user_next(user_ns, n);
|
2009-02-27 08:28:04 +08:00
|
|
|
}
|
2009-09-02 16:14:11 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
|
2009-06-18 20:00:05 +08:00
|
|
|
__acquires(key_user_lock)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
|
|
|
struct rb_node *_p;
|
|
|
|
loff_t pos = *_pos;
|
|
|
|
|
|
|
|
spin_lock(&key_user_lock);
|
|
|
|
|
2012-02-08 23:53:04 +08:00
|
|
|
_p = key_user_first(seq_user_ns(p), &key_user_tree);
|
2005-04-17 06:20:36 +08:00
|
|
|
while (pos > 0 && _p) {
|
|
|
|
pos--;
|
2012-02-08 23:53:04 +08:00
|
|
|
_p = key_user_next(seq_user_ns(p), _p);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
return _p;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
|
|
|
|
{
|
|
|
|
(*_pos)++;
|
2012-02-08 23:53:04 +08:00
|
|
|
return key_user_next(seq_user_ns(p), (struct rb_node *)v);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
static void proc_key_users_stop(struct seq_file *p, void *v)
|
2009-06-18 20:00:05 +08:00
|
|
|
__releases(key_user_lock)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
|
|
|
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);
|
2012-02-08 23:53:04 +08:00
|
|
|
unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
|
2008-04-29 16:01:32 +08:00
|
|
|
key_quota_root_maxkeys : key_quota_maxkeys;
|
2012-02-08 23:53:04 +08:00
|
|
|
unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
|
2008-04-29 16:01:32 +08:00
|
|
|
key_quota_root_maxbytes : key_quota_maxbytes;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
|
2012-02-08 23:53:04 +08:00
|
|
|
from_kuid_munged(seq_user_ns(m), user->uid),
|
2017-03-31 20:20:49 +08:00
|
|
|
refcount_read(&user->usage),
|
2005-04-17 06:20:36 +08:00
|
|
|
atomic_read(&user->nkeys),
|
|
|
|
atomic_read(&user->nikeys),
|
|
|
|
user->qnkeys,
|
2008-04-29 16:01:32 +08:00
|
|
|
maxkeys,
|
2005-04-17 06:20:36 +08:00
|
|
|
user->qnbytes,
|
2008-04-29 16:01:32 +08:00
|
|
|
maxbytes);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|