From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 18 Feb 2025 15:42:18 +0000 (+0900)
Subject: terminal-util: fix possible NULL pointer dereference
X-Git-Tag: v258-rc1~1311
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a6eb22968c3e59fb86ac2dbb4c4edfcc57c8f7d1;p=thirdparty%2Fsystemd.git

terminal-util: fix possible NULL pointer dereference

Fixes a bug introduced by 94a2b1cd25c93870a7a4ac904f6c0f2e4f902038.
Fixes CID#1591787.
---

diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
index 0a185776303..fce3bb95a3c 100644
--- a/src/basic/terminal-util.c
+++ b/src/basic/terminal-util.c
@@ -419,7 +419,10 @@ int ask_string_full(
                         /* Ctrl-u → erase all input */
 
                         clear_by_backspace(utf8_console_width(string));
-                        string[n = 0] = 0;
+                        if (string)
+                                string[n = 0] = 0;
+                        else
+                                assert(n == 0);
 
                 } else if (c == 4) {
                         /* Ctrl-d → cancel this field input */