Merge branch 'fixes-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull keys fixes from James Morris:

 - Handle quotas better, allowing full quota to be reached.

 - Fix the creation of shortcuts in the assoc_array internal
   representation when the index key needs to be an exact multiple of
   the machine word size.

 - Fix a dependency loop between the request_key contruction record and
   the request_key authentication key. The construction record isn't
   really necessary and can be dispensed with.

 - Set the timestamp on a new key rather than leaving it as 0. This
   would ordinarily be fine - provided the system clock is never set to
   a time before 1970

* 'fixes-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  keys: Timestamp new keys
  keys: Fix dependency loop between construction record and auth key
  assoc_array: Fix shortcut creation
  KEYS: allow reaching the keys quotas exactly

10 files changed, 108 insertions, 97 deletions

diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
index 3f23b6840547..bf34ddaa2ad7 100644
--- a/fs/nfs/nfs4idmap.c
+++ b/fs/nfs/nfs4idmap.c
@@ -44,6 +44,7 @@
 #include <linux/keyctl.h>
 #include <linux/key-type.h>
 #include <keys/user-type.h>
+#include <keys/request_key_auth-type.h>
 #include <linux/module.h>
 
 #include "internal.h"
@@ -59,7 +60,7 @@ static struct key_type key_type_id_resolver_legacy;
 struct idmap_legacy_upcalldata {
 	struct rpc_pipe_msg pipe_msg;
 	struct idmap_msg idmap_msg;
-	struct key_construction	*key_cons;
+	struct key	*authkey;
 	struct idmap *idmap;
 };
 
@@ -384,7 +385,7 @@ static const match_table_t nfs_idmap_tokens = {
 	{ Opt_find_err, NULL }
 };
 
-static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
+static int nfs_idmap_legacy_upcall(struct key *, void *);
 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 				   size_t);
 static void idmap_release_pipe(struct inode *);
@@ -549,11 +550,12 @@ nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 static void
 nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
 {
-	struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
+	struct key *authkey = idmap->idmap_upcall_data->authkey;
 
 	kfree(idmap->idmap_upcall_data);
 	idmap->idmap_upcall_data = NULL;
-	complete_request_key(cons, ret);
+	complete_request_key(authkey, ret);
+	key_put(authkey);
 }
 
 static void
@@ -563,15 +565,14 @@ nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
 		nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
 }
 
-static int nfs_idmap_legacy_upcall(struct key_construction *cons,
-				   const char *op,
-				   void *aux)
+static int nfs_idmap_legacy_upcall(struct key *authkey, void *aux)
 {
 	struct idmap_legacy_upcalldata *data;
+	struct request_key_auth *rka = get_request_key_auth(authkey);
 	struct rpc_pipe_msg *msg;
 	struct idmap_msg *im;
 	struct idmap *idmap = (struct idmap *)aux;
-	struct key *key = cons->key;
+	struct key *key = rka->target_key;
 	int ret = -ENOKEY;
 
 	if (!aux)
@@ -586,7 +587,7 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 	msg = &data->pipe_msg;
 	im = &data->idmap_msg;
 	data->idmap = idmap;
-	data->key_cons = cons;
+	data->authkey = key_get(authkey);
 
 	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 	if (ret < 0)
@@ -604,7 +605,7 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 out2:
 	kfree(data);
 out1:
-	complete_request_key(cons, ret);
+	complete_request_key(authkey, ret);
 	return ret;
 }
 
@@ -651,9 +652,10 @@ out:
 static ssize_t
 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 {
+	struct request_key_auth *rka;
 	struct rpc_inode *rpci = RPC_I(file_inode(filp));
 	struct idmap *idmap = (struct idmap *)rpci->private;
-	struct key_construction *cons;
+	struct key *authkey;
 	struct idmap_msg im;
 	size_t namelen_in;
 	int ret = -ENOKEY;
@@ -665,7 +667,8 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	if (idmap->idmap_upcall_data == NULL)
 		goto out_noupcall;
 
-	cons = idmap->idmap_upcall_data->key_cons;
+	authkey = idmap->idmap_upcall_data->authkey;
+	rka = get_request_key_auth(authkey);
 
 	if (mlen != sizeof(im)) {
 		ret = -ENOSPC;
@@ -690,9 +693,9 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 
 	ret = nfs_idmap_read_and_verify_message(&im,
 			&idmap->idmap_upcall_data->idmap_msg,
-			cons->key, cons->authkey);
+			rka->target_key, authkey);
 	if (ret >= 0) {
-		key_set_timeout(cons->key, nfs_idmap_cache_timeout);
+		key_set_timeout(rka->target_key, nfs_idmap_cache_timeout);
 		ret = mlen;
 	}
 
diff --git a/include/keys/request_key_auth-type.h b/include/keys/request_key_auth-type.h
new file mode 100644
index 000000000000..a726dd3f1dc6
--- /dev/null
+++ b/include/keys/request_key_auth-type.h
@@ -0,0 +1,36 @@
+/* request_key authorisation token key type
+ *
+ * Copyright (C) 2005 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _KEYS_REQUEST_KEY_AUTH_TYPE_H
+#define _KEYS_REQUEST_KEY_AUTH_TYPE_H
+
+#include <linux/key.h>
+
+/*
+ * Authorisation record for request_key().
+ */
+struct request_key_auth {
+	struct key		*target_key;
+	struct key		*dest_keyring;
+	const struct cred	*cred;
+	void			*callout_info;
+	size_t			callout_len;
+	pid_t			pid;
+	char			op[8];
+} __randomize_layout;
+
+static inline struct request_key_auth *get_request_key_auth(const struct key *key)
+{
+	return key->payload.data[0];
+}
+
+
+#endif /* _KEYS_REQUEST_KEY_AUTH_TYPE_H */
diff --git a/include/linux/key-type.h b/include/linux/key-type.h
index bc9af551fc83..e49d1de0614e 100644
--- a/include/linux/key-type.h
+++ b/include/linux/key-type.h
@@ -21,15 +21,6 @@ struct kernel_pkey_query;
 struct kernel_pkey_params;
 
 /*
- * key under-construction record
- * - passed to the request_key actor if supplied
- */
-struct key_construction {
-	struct key	*key;	/* key being constructed */
-	struct key	*authkey;/* authorisation for key being constructed */
-};
-
-/*
  * Pre-parsed payload, used by key add, update and instantiate.
  *
  * This struct will be cleared and data and datalen will be set with the data
@@ -50,8 +41,7 @@ struct key_preparsed_payload {
 	time64_t	expiry;		/* Expiry time of key */
 } __randomize_layout;
 
-typedef int (*request_key_actor_t)(struct key_construction *key,
-				   const char *op, void *aux);
+typedef int (*request_key_actor_t)(struct key *auth_key, void *aux);
 
 /*
  * Preparsed matching criterion.
@@ -181,20 +171,20 @@ extern int key_instantiate_and_link(struct key *key,
 				    const void *data,
 				    size_t datalen,
 				    struct key *keyring,
-				    struct key *instkey);
+				    struct key *authkey);
 extern int key_reject_and_link(struct key *key,
 			       unsigned timeout,
 			       unsigned error,
 			       struct key *keyring,
-			       struct key *instkey);
-extern void complete_request_key(struct key_construction *cons, int error);
+			       struct key *authkey);
+extern void complete_request_key(struct key *authkey, int error);
 
 static inline int key_negate_and_link(struct key *key,
 				      unsigned timeout,
 				      struct key *keyring,
-				      struct key *instkey)
+				      struct key *authkey)
 {
-	return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey);
+	return key_reject_and_link(key, timeout, ENOKEY, keyring, authkey);
 }
 
 extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep);
diff --git a/lib/assoc_array.c b/lib/assoc_array.c
index c6659cb37033..59875eb278ea 100644
--- a/lib/assoc_array.c
+++ b/lib/assoc_array.c
@@ -768,9 +768,11 @@ all_leaves_cluster_together:
 		new_s0->index_key[i] =
 			ops->get_key_chunk(index_key, i * ASSOC_ARRAY_KEY_CHUNK_SIZE);
 
-	blank = ULONG_MAX << (level & ASSOC_ARRAY_KEY_CHUNK_MASK);
-	pr_devel("blank off [%zu] %d: %lx\n", keylen - 1, level, blank);
-	new_s0->index_key[keylen - 1] &= ~blank;
+	if (level & ASSOC_ARRAY_KEY_CHUNK_MASK) {
+		blank = ULONG_MAX << (level & ASSOC_ARRAY_KEY_CHUNK_MASK);
+		pr_devel("blank off [%zu] %d: %lx\n", keylen - 1, level, blank);
+		new_s0->index_key[keylen - 1] &= ~blank;
+	}
 
 	/* This now reduces to a node splitting exercise for which we'll need
 	 * to regenerate the disparity table.
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 479909b858c7..8f533c81aa8d 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -186,20 +186,9 @@ static inline int key_permission(const key_ref_t key_ref, unsigned perm)
 	return key_task_permission(key_ref, current_cred(), perm);
 }
 
-/*
- * Authorisation record for request_key().
- */
-struct request_key_auth {
-	struct key		*target_key;
-	struct key		*dest_keyring;
-	const struct cred	*cred;
-	void			*callout_info;
-	size_t			callout_len;
-	pid_t			pid;
-} __randomize_layout;
-
 extern struct key_type key_type_request_key_auth;
 extern struct key *request_key_auth_new(struct key *target,
+					const char *op,
 					const void *callout_info,
 					size_t callout_len,
 					struct key *dest_keyring);
diff --git a/security/keys/key.c b/security/keys/key.c
index 44a80d6741a1..696f1c092c50 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -265,8 +265,8 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 
 		spin_lock(&user->lock);
 		if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
-			if (user->qnkeys + 1 >= maxkeys ||
-			    user->qnbytes + quotalen >= maxbytes ||
+			if (user->qnkeys + 1 > maxkeys ||
+			    user->qnbytes + quotalen > maxbytes ||
 			    user->qnbytes + quotalen < user->qnbytes)
 				goto no_quota;
 		}
@@ -297,6 +297,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 	key->gid = gid;
 	key->perm = perm;
 	key->restrict_link = restrict_link;
+	key->last_used_at = ktime_get_real_seconds();
 
 	if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index e8093d025966..7bbe03593e58 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -25,6 +25,7 @@
 #include <linux/security.h>
 #include <linux/uio.h>
 #include <linux/uaccess.h>
+#include <keys/request_key_auth-type.h>
 #include "internal.h"
 
 #define KEY_MAX_DESC_SIZE 4096
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 02c77e928f68..0e0b9ccad2f8 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -19,6 +19,7 @@
 #include <linux/security.h>
 #include <linux/user_namespace.h>
 #include <linux/uaccess.h>
+#include <keys/request_key_auth-type.h>
 #include "internal.h"
 
 /* Session keyring create vs join semaphore */
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 301f0e300dbd..3f56a312dd35 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -18,31 +18,30 @@
 #include <linux/keyctl.h>
 #include <linux/slab.h>
 #include "internal.h"
+#include <keys/request_key_auth-type.h>
 
 #define key_negative_timeout	60	/* default timeout on a negative key's existence */
 
 /**
  * complete_request_key - Complete the construction of a key.
- * @cons: The key construction record.
+ * @auth_key: The authorisation key.
  * @error: The success or failute of the construction.
  *
  * Complete the attempt to construct a key.  The key will be negated
  * if an error is indicated.  The authorisation key will be revoked
  * unconditionally.
  */
-void complete_request_key(struct key_construction *cons, int error)
+void complete_request_key(struct key *authkey, int error)
 {
-	kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
+	struct request_key_auth *rka = get_request_key_auth(authkey);
+	struct key *key = rka->target_key;
+
+	kenter("%d{%d},%d", authkey->serial, key->serial, error);
 
 	if (error < 0)
-		key_negate_and_link(cons->key, key_negative_timeout, NULL,
-				    cons->authkey);
+		key_negate_and_link(key, key_negative_timeout, NULL, authkey);
 	else
-		key_revoke(cons->authkey);
-
-	key_put(cons->key);
-	key_put(cons->authkey);
-	kfree(cons);
+		key_revoke(authkey);
 }
 EXPORT_SYMBOL(complete_request_key);
 
@@ -91,21 +90,19 @@ static int call_usermodehelper_keys(const char *path, char **argv, char **envp,
  * Request userspace finish the construction of a key
  * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
  */
-static int call_sbin_request_key(struct key_construction *cons,
-				 const char *op,
-				 void *aux)
+static int call_sbin_request_key(struct key *authkey, void *aux)
 {
 	static char const request_key[] = "/sbin/request-key";
+	struct request_key_auth *rka = get_request_key_auth(authkey);
 	const struct cred *cred = current_cred();
 	key_serial_t prkey, sskey;
-	struct key *key = cons->key, *authkey = cons->authkey, *keyring,
-		*session;
+	struct key *key = rka->target_key, *keyring, *session;
 	char *argv[9], *envp[3], uid_str[12], gid_str[12];
 	char key_str[12], keyring_str[3][12];
 	char desc[20];
 	int ret, i;
 
-	kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
+	kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op);
 
 	ret = install_user_keyrings();
 	if (ret < 0)
@@ -163,7 +160,7 @@ static int call_sbin_request_key(struct key_construction *cons,
 	/* set up the argument list */
 	i = 0;
 	argv[i++] = (char *)request_key;
-	argv[i++] = (char *) op;
+	argv[i++] = (char *)rka->op;
 	argv[i++] = key_str;
 	argv[i++] = uid_str;
 	argv[i++] = gid_str;
@@ -191,7 +188,7 @@ error_link:
 	key_put(keyring);
 
 error_alloc:
-	complete_request_key(cons, ret);
+	complete_request_key(authkey, ret);
 	kleave(" = %d", ret);
 	return ret;
 }
@@ -205,42 +202,31 @@ static int construct_key(struct key *key, const void *callout_info,
 			 size_t callout_len, void *aux,
 			 struct key *dest_keyring)
 {
-	struct key_construction *cons;
 	request_key_actor_t actor;
 	struct key *authkey;
 	int ret;
 
 	kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
 
-	cons = kmalloc(sizeof(*cons), GFP_KERNEL);
-	if (!cons)
-		return -ENOMEM;
-
 	/* allocate an authorisation key */
-	authkey = request_key_auth_new(key, callout_info, callout_len,
+	authkey = request_key_auth_new(key, "create", callout_info, callout_len,
 				       dest_keyring);
-	if (IS_ERR(authkey)) {
-		kfree(cons);
-		ret = PTR_ERR(authkey);
-		authkey = NULL;
-	} else {
-		cons->authkey = key_get(authkey);
-		cons->key = key_get(key);
+	if (IS_ERR(authkey))
+		return PTR_ERR(authkey);
 
-		/* make the call */
-		actor = call_sbin_request_key;
-		if (key->type->request_key)
-			actor = key->type->request_key;
+	/* Make the call */
+	actor = call_sbin_request_key;
+	if (key->type->request_key)
+		actor = key->type->request_key;
 
-		ret = actor(cons, "create", aux);
+	ret = actor(authkey, aux);
 
-		/* check that the actor called complete_request_key() prior to
-		 * returning an error */
-		WARN_ON(ret < 0 &&
-			!test_bit(KEY_FLAG_REVOKED, &authkey->flags));
-		key_put(authkey);
-	}
+	/* check that the actor called complete_request_key() prior to
+	 * returning an error */
+	WARN_ON(ret < 0 &&
+		!test_bit(KEY_FLAG_REVOKED, &authkey->flags));
 
+	key_put(authkey);
 	kleave(" = %d", ret);
 	return ret;
 }
@@ -275,7 +261,7 @@ static int construct_get_dest_keyring(struct key **_dest_keyring)
 			if (cred->request_key_auth) {
 				authkey = cred->request_key_auth;
 				down_read(&authkey->sem);
-				rka = authkey->payload.data[0];
+				rka = get_request_key_auth(authkey);
 				if (!test_bit(KEY_FLAG_REVOKED,
 					      &authkey->flags))
 					dest_keyring =
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 87ea2f54dedc..afc304e8b61e 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -17,7 +17,7 @@
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include "internal.h"
-#include <keys/user-type.h>
+#include <keys/request_key_auth-type.h>
 
 static int request_key_auth_preparse(struct key_preparsed_payload *);
 static void request_key_auth_free_preparse(struct key_preparsed_payload *);
@@ -68,7 +68,7 @@ static int request_key_auth_instantiate(struct key *key,
 static void request_key_auth_describe(const struct key *key,
 				      struct seq_file *m)
 {
-	struct request_key_auth *rka = key->payload.data[0];
+	struct request_key_auth *rka = get_request_key_auth(key);
 
 	seq_puts(m, "key:");
 	seq_puts(m, key->description);
@@ -83,7 +83,7 @@ static void request_key_auth_describe(const struct key *key,
 static long request_key_auth_read(const struct key *key,
 				  char __user *buffer, size_t buflen)
 {
-	struct request_key_auth *rka = key->payload.data[0];
+	struct request_key_auth *rka = get_request_key_auth(key);
 	size_t datalen;
 	long ret;
 
@@ -109,7 +109,7 @@ static long request_key_auth_read(const struct key *key,
  */
 static void request_key_auth_revoke(struct key *key)
 {
-	struct request_key_auth *rka = key->payload.data[0];
+	struct request_key_auth *rka = get_request_key_auth(key);
 
 	kenter("{%d}", key->serial);
 
@@ -136,7 +136,7 @@ static void free_request_key_auth(struct request_key_auth *rka)
  */
 static void request_key_auth_destroy(struct key *key)
 {
-	struct request_key_auth *rka = key->payload.data[0];
+	struct request_key_auth *rka = get_request_key_auth(key);
 
 	kenter("{%d}", key->serial);
 
@@ -147,8 +147,9 @@ static void request_key_auth_destroy(struct key *key)
  * Create an authorisation token for /sbin/request-key or whoever to gain
  * access to the caller's security data.
  */
-struct key *request_key_auth_new(struct key *target, const void *callout_info,
-				 size_t callout_len, struct key *dest_keyring)
+struct key *request_key_auth_new(struct key *target, const char *op,
+				 const void *callout_info, size_t callout_len,
+				 struct key *dest_keyring)
 {
 	struct request_key_auth *rka, *irka;
 	const struct cred *cred = current->cred;
@@ -166,6 +167,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
 	if (!rka->callout_info)
 		goto error_free_rka;
 	rka->callout_len = callout_len;
+	strlcpy(rka->op, op, sizeof(rka->op));
 
 	/* see if the calling process is already servicing the key request of
 	 * another process */