diff --git a/[refs] b/[refs]
index 65784770857f..2260621253da 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 92f6fa09bd453ffe3351fa1f1377a1b7cfa911e6
+refs/heads/master: 2872628680bad71a6734e7d379168f990a91cc09
diff --git a/trunk/drivers/tty/n_tty.c b/trunk/drivers/tty/n_tty.c
index 0ad32888091c..c3954fbf6ac4 100644
--- a/trunk/drivers/tty/n_tty.c
+++ b/trunk/drivers/tty/n_tty.c
@@ -1815,6 +1815,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 			/* FIXME: does n_tty_set_room need locking ? */
 			n_tty_set_room(tty);
 			timeout = schedule_timeout(timeout);
+			BUG_ON(!tty->read_buf);
 			continue;
 		}
 		__set_current_state(TASK_RUNNING);