CRED: Separate per-task-group keyrings from signal_struct

Separate per-task-group keyrings from signal_struct and dangle their anchor
from the cred struct rather than the signal_struct.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 14 insertions, 20 deletions

diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 0488b0af5bd6..3d12558362df 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -66,7 +66,6 @@ static int call_sbin_request_key(struct key_construction *cons,
                                  const char *op,
                                  void *aux)
 {
-        struct task_struct *tsk = current;
         const struct cred *cred = current_cred();
         key_serial_t prkey, sskey;
         struct key *key = cons->key, *authkey = cons->authkey, *keyring;
@@ -109,18 +108,13 @@ static int call_sbin_request_key(struct key_construction *cons,
                 cred->thread_keyring->serial : 0);
 
         prkey = 0;
-        if (tsk->signal->process_keyring)
-                prkey = tsk->signal->process_keyring->serial;
+        if (cred->tgcred->process_keyring)
+                prkey = cred->tgcred->process_keyring->serial;
 
-        sprintf(keyring_str[1], "%d", prkey);
-
-        if (tsk->signal->session_keyring) {
-                rcu_read_lock();
-                sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
-                rcu_read_unlock();
-        } else {
+        if (cred->tgcred->session_keyring)
+                sskey = rcu_dereference(cred->tgcred->session_keyring)->serial;
+        else
                 sskey = cred->user->session_keyring->serial;
-        }
 
         sprintf(keyring_str[2], "%d", sskey);
 
@@ -222,7 +216,7 @@ static int construct_key(struct key *key, const void *callout_info,
 static void construct_get_dest_keyring(struct key **_dest_keyring)
 {
         struct request_key_auth *rka;
-        struct task_struct *tsk = current;
+        const struct cred *cred = current_cred();
         struct key *dest_keyring = *_dest_keyring, *authkey;
 
         kenter("%p", dest_keyring);
@@ -234,11 +228,11 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
         } else {
                 /* use a default keyring; falling through the cases until we
                  * find one that we actually have */
-                switch (tsk->cred->jit_keyring) {
+                switch (cred->jit_keyring) {
                 case KEY_REQKEY_DEFL_DEFAULT:
                 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
-                        if (tsk->cred->request_key_auth) {
-                                authkey = tsk->cred->request_key_auth;
+                        if (cred->request_key_auth) {
+                                authkey = cred->request_key_auth;
                                 down_read(&authkey->sem);
                                 rka = authkey->payload.data;
                                 if (!test_bit(KEY_FLAG_REVOKED,
@@ -251,19 +245,19 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
                         }
 
                 case KEY_REQKEY_DEFL_THREAD_KEYRING:
-                        dest_keyring = key_get(tsk->cred->thread_keyring);
+                        dest_keyring = key_get(cred->thread_keyring);
                         if (dest_keyring)
                                 break;
 
                 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
-                        dest_keyring = key_get(tsk->signal->process_keyring);
+                        dest_keyring = key_get(cred->tgcred->process_keyring);
                         if (dest_keyring)
                                 break;
 
                 case KEY_REQKEY_DEFL_SESSION_KEYRING:
                         rcu_read_lock();
                         dest_keyring = key_get(
-                                rcu_dereference(tsk->signal->session_keyring));
+                                rcu_dereference(cred->tgcred->session_keyring));
                         rcu_read_unlock();
 
                         if (dest_keyring)
@@ -271,11 +265,11 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
 
                 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
                         dest_keyring =
-                                key_get(tsk->cred->user->session_keyring);
+                                key_get(cred->user->session_keyring);
                         break;
 
                 case KEY_REQKEY_DEFL_USER_KEYRING:
-                        dest_keyring = key_get(tsk->cred->user->uid_keyring);
+                        dest_keyring = key_get(cred->user->uid_keyring);
                         break;
 
                 case KEY_REQKEY_DEFL_GROUP_KEYRING: