From 782e6e3987be6d579ba7d28dadd9f358fd47d773 Mon Sep 17 00:00:00 2001
From: Rafal Kupiec <belliash@codingworkshop.eu.org>
Date: Thu, 21 Dec 2023 20:02:02 +0100
Subject: [PATCH] Make sure config list is not empty before trying to access it

---
 xtldr2/config.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/xtldr2/config.c b/xtldr2/config.c
index 28d9927..7a34cf1 100644
--- a/xtldr2/config.c
+++ b/xtldr2/config.c
@@ -30,22 +30,26 @@ BlGetConfigValue(IN CONST PWCHAR ConfigName)
     /* Get config entry name length */
     Length = RtlWideStringLength(ConfigName, 0);
 
-    /* Iterate through config entries */
-    ConfigListEntry = BlpConfig->Flink;
-    while(ConfigListEntry != BlpConfig)
+    /* Make sure config list is not empty */
+    if(BlpConfig != NULL)
     {
-        /* Get config entry */
-        ConfigEntry = CONTAIN_RECORD(ConfigListEntry, XTBL_CONFIG_ENTRY, Flink);
-
-        /* Check if requested configuration found */
-        if(RtlCompareWideStringInsensitive(ConfigEntry->Name, ConfigName, Length) == 0)
+        /* Iterate through config entries */
+        ConfigListEntry = BlpConfig->Flink;
+        while(ConfigListEntry != BlpConfig)
         {
-            /* Return config value */
-            return ConfigEntry->Value;
-        }
+            /* Get config entry */
+            ConfigEntry = CONTAIN_RECORD(ConfigListEntry, XTBL_CONFIG_ENTRY, Flink);
 
-        /* Move to the next config entry */
-        ConfigListEntry = ConfigListEntry->Flink;
+            /* Check if requested configuration found */
+            if(RtlCompareWideStringInsensitive(ConfigEntry->Name, ConfigName, Length) == 0)
+            {
+                /* Return config value */
+                return ConfigEntry->Value;
+            }
+
+            /* Move to the next config entry */
+            ConfigListEntry = ConfigListEntry->Flink;
+        }
     }
 
     /* Config entry not found, return NULL */