1 files changed, 146 insertions, 49 deletions

diff --git a/security/keys/proc.c b/security/keys/proc.c
index 694126003ed..d3f6f2fd21d 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -1,4 +1,4 @@
-/* proc.c: proc files for key database enumeration
+/* procfs files for key database enumeration
  *
  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
@@ -12,7 +12,6 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/sched.h>
-#include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
@@ -61,71 +60,122 @@ static const struct file_operations proc_key_users_fops = {
 	.release	= seq_release,
 };
 
-/*****************************************************************************/
 /*
- * declare the /proc files
+ * Declare the /proc files.
  */
 static int __init key_proc_init(void)
 {
 	struct proc_dir_entry *p;
 
 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
-	p = create_proc_entry("keys", 0, NULL);
+	p = proc_create("keys", 0, NULL, &proc_keys_fops);
 	if (!p)
 		panic("Cannot create /proc/keys\n");
-
-	p->proc_fops = &proc_keys_fops;
 #endif
 
-	p = create_proc_entry("key-users", 0, NULL);
+	p = proc_create("key-users", 0, NULL, &proc_key_users_fops);
 	if (!p)
 		panic("Cannot create /proc/key-users\n");
 
-	p->proc_fops = &proc_key_users_fops;
-
 	return 0;
-
-} /* end key_proc_init() */
+}
 
 __initcall(key_proc_init);
 
-/*****************************************************************************/
 /*
- * implement "/proc/keys" to provides a list of the keys on the system
+ * Implement "/proc/keys" to provide a list of the keys on the system that
+ * grant View permission to the caller.
  */
 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
 
+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 int proc_keys_open(struct inode *inode, struct file *file)
 {
 	return seq_open(file, &proc_keys_ops);
+}
+
+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)
 {
-	struct rb_node *_p;
-	loff_t pos = *_pos;
+	key_serial_t pos = *_pos;
+	struct key *key;
 
 	spin_lock(&key_serial_lock);
 
-	_p = rb_first(&key_serial_tree);
-	while (pos > 0 && _p) {
-		pos--;
-		_p = rb_next(_p);
-	}
-
-	return _p;
+	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)
 {
-	(*_pos)++;
-	return rb_next((struct rb_node *) v);
+	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);
 }
@@ -136,12 +186,39 @@ static int proc_keys_show(struct seq_file *m, void *v)
 	struct key *key = rb_entry(_p, struct key, serial_node);
 	struct timespec now;
 	unsigned long timo;
+	key_ref_t key_ref, skey_ref;
 	char xbuf[12];
 	int rc;
 
+	struct keyring_search_context ctx = {
+		.index_key.type		= key->type,
+		.index_key.description	= key->description,
+		.cred			= current_cred(),
+		.match			= lookup_user_key_possessed,
+		.match_data		= key,
+		.flags			= (KEYRING_SEARCH_NO_STATE_CHECK |
+					   KEYRING_SEARCH_LOOKUP_DIRECT),
+	};
+
+	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 (assuming
-	 * non-possession) */
-	rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW);
+	 * non-possession)
+	 * - the caller holds a spinlock, and thus the RCU read lock, making our
+	 *   access to __current_cred() safe
+	 */
+	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
 	if (rc < 0)
 		return 0;
 
@@ -152,11 +229,9 @@ static int proc_keys_show(struct seq_file *m, void *v)
 	/* come up with a suitable timeout value */
 	if (key->expiry == 0) {
 		memcpy(xbuf, "perm", 5);
-	}
-	else if (now.tv_sec >= key->expiry) {
+	} else if (now.tv_sec >= key->expiry) {
 		memcpy(xbuf, "expd", 5);
-	}
-	else {
+	} else {
 		timo = key->expiry - now.tv_sec;
 
 		if (timo < 60)
@@ -174,7 +249,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
 #define showflag(KEY, LETTER, FLAG) \
 	(test_bit(FLAG,	&(KEY)->flags) ? LETTER : '-')
 
-	seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
+	seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
 		   key->serial,
 		   showflag(key, 'I', KEY_FLAG_INSTANTIATED),
 		   showflag(key, 'R', KEY_FLAG_REVOKED),
@@ -182,11 +257,12 @@ static int proc_keys_show(struct seq_file *m, void *v)
 		   showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
 		   showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
 		   showflag(key, 'N', KEY_FLAG_NEGATIVE),
+		   showflag(key, 'i', KEY_FLAG_INVALIDATED),
 		   atomic_read(&key->usage),
 		   xbuf,
 		   key->perm,
-		   key->uid,
-		   key->gid,
+		   from_kuid_munged(seq_user_ns(m), key->uid),
+		   from_kgid_munged(seq_user_ns(m), key->gid),
 		   key->type->name);
 
 #undef showflag
@@ -196,48 +272,67 @@ static int proc_keys_show(struct seq_file *m, void *v)
 	seq_putc(m, '\n');
 
 	rcu_read_unlock();
-
 	return 0;
-
 }
 
 #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */
 
-/*****************************************************************************/
+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);
+}
+
 /*
- * implement "/proc/key-users" to provides a list of the key users
+ * Implement "/proc/key-users" to provides a list of the key users and their
+ * quotas.
  */
 static int proc_key_users_open(struct inode *inode, struct file *file)
 {
 	return seq_open(file, &proc_key_users_ops);
-
 }
 
 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 = rb_first(&key_user_tree);
+	_p = key_user_first(seq_user_ns(p), &key_user_tree);
 	while (pos > 0 && _p) {
 		pos--;
-		_p = rb_next(_p);
+		_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 rb_next((struct rb_node *) v);
-
+	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);
 }
@@ -246,18 +341,20 @@ 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",
-		   user->uid,
+		   from_kuid_munged(seq_user_ns(m), user->uid),
 		   atomic_read(&user->usage),
 		   atomic_read(&user->nkeys),
 		   atomic_read(&user->nikeys),
 		   user->qnkeys,
-		   KEYQUOTA_MAX_KEYS,
+		   maxkeys,
 		   user->qnbytes,
-		   KEYQUOTA_MAX_BYTES
-		   );
+		   maxbytes);
 
 	return 0;
-
 }