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 */
-};
-
-/*