1 files changed, 5 insertions, 1 deletions

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index b2b0998d6abd..60924f6a52db 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1272,6 +1272,7 @@ long keyctl_session_to_parent(void)
         keyring_r = NULL;
 
         me = current;
+        rcu_read_lock();
         write_lock_irq(&tasklist_lock);
 
         parent = me->real_parent;
@@ -1304,7 +1305,8 @@ long keyctl_session_to_parent(void)
                 goto not_permitted;
 
         /* the keyrings must have the same UID */
-        if (pcred->tgcred->session_keyring->uid != mycred->euid ||
+        if ((pcred->tgcred->session_keyring &&
+             pcred->tgcred->session_keyring->uid != mycred->euid) ||
             mycred->tgcred->session_keyring->uid != mycred->euid)
                 goto not_permitted;
 
@@ -1319,6 +1321,7 @@ long keyctl_session_to_parent(void)
         set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
 
         write_unlock_irq(&tasklist_lock);
+        rcu_read_unlock();
         if (oldcred)
                 put_cred(oldcred);
         return 0;
@@ -1327,6 +1330,7 @@ already_same:
         ret = 0;
 not_permitted:
         write_unlock_irq(&tasklist_lock);
+        rcu_read_unlock();
         put_cred(cred);
         return ret;