From 2819d3fb7943aecae5f8b3821e49607678217245 Mon Sep 17 00:00:00 2001
From: Harald Welte <laforge@osmocom.org>
Date: Mon, 28 Mar 2022 10:11:05 +0200
Subject: [PATCH] intf_line.c: Make e1d_find_intf_by_usb_serial safe for empty
 string

Avoid segfault in case the empty string is passed as serial_str.

Change-Id: Ia69912cb714441415d8decd68890d1b97b77132d
---
 src/intf_line.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/intf_line.c b/src/intf_line.c
index 0ff3942..c9011a8 100644
--- a/src/intf_line.c
+++ b/src/intf_line.c
@@ -100,6 +100,9 @@ e1d_find_intf_by_usb_serial(struct e1_daemon *e1d, const char *serial_str)
 {
 	struct e1_intf *intf;
 
+	if (!serial_str)
+		return NULL;
+
 	llist_for_each_entry(intf, &e1d->interfaces, list)
 		if (intf->usb.serial_str && !strcmp(intf->usb.serial_str, serial_str))
 			return intf;