diff --git a/drivers/tty/tty_jobctrl.c b/drivers/tty/tty_jobctrl.c
index 56c791c81b4f9a2b3f4a0f412573bcfece426a30..b363c838032ea4746d68e3a7ee8647141b7f1767 100644
--- a/drivers/tty/tty_jobctrl.c
+++ b/drivers/tty/tty_jobctrl.c
@@ -290,12 +290,7 @@ void disassociate_ctty(int on_exit)
 		return;
 	}
 
-	spin_lock_irq(&current->sighand->siglock);
-	put_pid(current->signal->tty_old_pgrp);
-	current->signal->tty_old_pgrp = NULL;
-	tty = tty_kref_get(current->signal->tty);
-	spin_unlock_irq(&current->sighand->siglock);
-
+	tty = get_current_tty();
 	if (tty) {
 		unsigned long flags;
 
@@ -308,20 +303,18 @@ void disassociate_ctty(int on_exit)
 		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		tty_unlock(tty);
 		tty_kref_put(tty);
-
-		/*
-		 * Race with tty_signal_session_leader(), current->signal
-		 * ->tty_old_pgrp may be reassigned, put_pid() again to ensure
-		 *  the pid does not leak memory.
-		 */
-		if (on_exit) {
-			spin_lock_irq(&current->sighand->siglock);
-			put_pid(current->signal->tty_old_pgrp);
-			current->signal->tty_old_pgrp = NULL;
-			spin_unlock_irq(&current->sighand->siglock);
-		}
 	}
 
+	/* If tty->ctrl.pgrp is not NULL, it may be assigned to
+	 * current->signal->tty_old_pgrp in a race condition, and
+	 * cause pid memleak. Release current->signal->tty_old_pgrp
+	 * after tty->ctrl.pgrp set to NULL.
+	 */
+	spin_lock_irq(&current->sighand->siglock);
+	put_pid(current->signal->tty_old_pgrp);
+	current->signal->tty_old_pgrp = NULL;
+	spin_unlock_irq(&current->sighand->siglock);
+
 	/* Now clear signal->tty under the lock */
 	read_lock(&tasklist_lock);
 	session_clear_tty(task_session(current));