[PATCH] keys: sort out key quota system

Add the ability for key creation to overrun the user's quota in some
circumstances - notably when a session keyring is created and assigned to a
process that didn't previously have one.

This means it's still possible to log in, should PAM require the creation of a
new session keyring, and fix an overburdened key quota.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 21 insertions, 15 deletions

diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index eab66a06ca53..58d1efd4fc2c 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -48,8 +48,8 @@ static int call_sbin_request_key(struct key *key,
         /* allocate a new session keyring */
         sprintf(desc, "_req.%u", key->serial);
 
-        keyring = keyring_alloc(desc, current->fsuid, current->fsgid,
-                                current, 1, NULL);
+        keyring = keyring_alloc(desc, current->fsuid, current->fsgid, current,
+                                KEY_ALLOC_QUOTA_OVERRUN, NULL);
         if (IS_ERR(keyring)) {
                 ret = PTR_ERR(keyring);
                 goto error_alloc;
@@ -126,7 +126,8 @@ error_alloc:
  */
 static struct key *__request_key_construction(struct key_type *type,
                                               const char *description,
-                                              const char *callout_info)
+                                              const char *callout_info,
+                                              unsigned long flags)
 {
         request_key_actor_t actor;
         struct key_construction cons;
@@ -134,12 +135,12 @@ static struct key *__request_key_construction(struct key_type *type,
         struct key *key, *authkey;
         int ret, negated;
 
-        kenter("%s,%s,%s", type->name, description, callout_info);
+        kenter("%s,%s,%s,%lx", type->name, description, callout_info, flags);
 
         /* create a key and add it to the queue */
         key = key_alloc(type, description,
-                        current->fsuid, current->fsgid,
-                        current, KEY_POS_ALL, 0);
+                        current->fsuid, current->fsgid, current, KEY_POS_ALL,
+                        flags);
         if (IS_ERR(key))
                 goto alloc_failed;
 
@@ -258,15 +259,16 @@ alloc_failed:
 static struct key *request_key_construction(struct key_type *type,
                                             const char *description,
                                             struct key_user *user,
-                                            const char *callout_info)
+                                            const char *callout_info,
+                                            unsigned long flags)
 {
         struct key_construction *pcons;
         struct key *key, *ckey;
 
         DECLARE_WAITQUEUE(myself, current);
 
-        kenter("%s,%s,{%d},%s",
-               type->name, description, user->uid, callout_info);
+        kenter("%s,%s,{%d},%s,%lx",
+               type->name, description, user->uid, callout_info, flags);
 
         /* see if there's such a key under construction already */
         down_write(&key_construction_sem);
@@ -282,7 +284,8 @@ static struct key *request_key_construction(struct key_type *type,
         }
 
         /* see about getting userspace to construct the key */
-        key = __request_key_construction(type, description, callout_info);
+        key = __request_key_construction(type, description, callout_info,
+                                         flags);
  error:
         kleave(" = %p", key);
         return key;
@@ -389,14 +392,15 @@ static void request_key_link(struct key *key, struct key *dest_keyring)
 struct key *request_key_and_link(struct key_type *type,
                                  const char *description,
                                  const char *callout_info,
-                                 struct key *dest_keyring)
+                                 struct key *dest_keyring,
+                                 unsigned long flags)
 {
         struct key_user *user;
         struct key *key;
         key_ref_t key_ref;
 
-        kenter("%s,%s,%s,%p",
-               type->name, description, callout_info, dest_keyring);
+        kenter("%s,%s,%s,%p,%lx",
+               type->name, description, callout_info, dest_keyring, flags);
 
         /* search all the process keyrings for a key */
         key_ref = search_process_keyrings(type, description, type->match,
@@ -429,7 +433,8 @@ struct key *request_key_and_link(struct key_type *type,
                         /* ask userspace (returns NULL if it waited on a key
                          * being constructed) */
                         key = request_key_construction(type, description,
-                                                       user, callout_info);
+                                                       user, callout_info,
+                                                       flags);
                         if (key)
                                 break;
 
@@ -485,7 +490,8 @@ struct key *request_key(struct key_type *type,
                         const char *description,
                         const char *callout_info)
 {
-        return request_key_and_link(type, description, callout_info, NULL);
+        return request_key_and_link(type, description, callout_info, NULL,
+                                    KEY_ALLOC_IN_QUOTA);
 
 } /* end request_key() */