keys: sparse: Fix incorrect RCU accesses

Fix a pair of accesses that should be using RCU protection.

rcu_dereference_protected() is needed to access task_struct::real_parent.

current_cred() should be used to access current->cred.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>

2 files changed, 3 insertions, 2 deletions

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 3e4053a217c3..0f947bcbad46 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1524,7 +1524,8 @@ long keyctl_session_to_parent(void)
 
         ret = -EPERM;
         oldwork = NULL;
-        parent = me->real_parent;
+        parent = rcu_dereference_protected(me->real_parent,
+                                           lockdep_is_held(&tasklist_lock));
 
         /* the parent mustn't be init and mustn't be a kernel thread */
         if (parent->pid <= 1 || !parent->mm)
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index bda6201c6c45..572c7a60473a 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -152,7 +152,7 @@ struct key *request_key_auth_new(struct key *target, const char *op,
                                  struct key *dest_keyring)
 {
         struct request_key_auth *rka, *irka;
-        const struct cred *cred = current->cred;
+        const struct cred *cred = current_cred();
         struct key *authkey = NULL;
         char desc[20];
         int ret = -ENOMEM;