From f5de3401b974ce103ffd93af8f9d43505a04aaf9 Mon Sep 17 00:00:00 2001
From: Damian Kurek <starfire24680@gmail.com>
Date: Thu, 7 Jul 2022 03:39:16 +0000
Subject: [PATCH] Fix NULL dereference when duplicating string argument

poptGetArg can return NULL if there are no additional arguments, which
makes strdup dereference NULL on strlen
---
 gptcl.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gptcl.cc b/gptcl.cc
index 0d578eb..ab95239 100644
--- a/gptcl.cc
+++ b/gptcl.cc
@@ -155,10 +155,11 @@ int GPTDataCL::DoOptions(int argc, char* argv[]) {
    } // while
 
    // Assume first non-option argument is the device filename....
-   device = strdup((char*) poptGetArg(poptCon));
-   poptResetContext(poptCon);
+   device = (char*) poptGetArg(poptCon);
 
    if (device != NULL) {
+      device = strdup(device);
+      poptResetContext(poptCon);
       JustLooking(); // reset as necessary
       BeQuiet(); // Tell called functions to be less verbose & interactive
       if (LoadPartitions((string) device)) {
@@ -498,6 +499,7 @@ int GPTDataCL::DoOptions(int argc, char* argv[]) {
          cerr << "Error encountered; not saving changes.\n";
          retval = 4;
       } // if
+      free(device);
    } // if (device != NULL)
    poptFreeContext(poptCon);
    return retval;