diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index fac058b..2c898c4 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -774,9 +774,11 @@
 	tty = winch->tty;
 	if (tty != NULL) {
 		line = tty->driver_data;
-		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
-				 &tty->winsize.ws_col);
-		kill_pgrp(tty->pgrp, SIGWINCH, 1);
+		if (line != NULL) {
+			chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+					 &tty->winsize.ws_col);
+			kill_pgrp(tty->pgrp, SIGWINCH, 1);
+		}
 	}
  out:
 	if (winch->fd != -1)
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index fabd75f..c953e14 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -792,6 +792,8 @@
 		printk(KERN_ERR "Failed to initialize management console\n");
 		return 1;
 	}
+	if (os_set_fd_block(sock, 0))
+		goto out;
 
 	register_reboot_notifier(&reboot_notifier);
 
@@ -800,7 +802,7 @@
 			     "mconsole", (void *)sock);
 	if (err) {
 		printk(KERN_ERR "Failed to get IRQ for management console\n");
-		return 1;
+		goto out;
 	}
 
 	if (notify_socket != NULL) {
@@ -816,6 +818,10 @@
 	printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
 	       MCONSOLE_VERSION, mconsole_socket_name);
 	return 0;
+
+ out:
+	os_close_file(sock);
+	return 1;
 }
 
 __initcall(mconsole_init);