diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5d37a09849163f..252849910588f6 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3157,6 +3157,8 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
 	mutex_unlock(&gsm->mutex);
 	/* Now wipe the queues */
 	tty_ldisc_flush(gsm->tty);
+
+	guard(spinlock_irqsave)(&gsm->tx_lock);
 	list_for_each_entry_safe(txq, ntxq, &gsm->tx_ctrl_list, list)
 		kfree(txq);
 	INIT_LIST_HEAD(&gsm->tx_ctrl_list);