From 4d8ad1c0363fc21f5d8a557f3319a6efacac9f2a Mon Sep 17 00:00:00 2001
From: SandakovMM <G0odvinSun@gmail.com>
Date: Thu, 24 Aug 2023 16:01:39 +0300
Subject: [PATCH 15/38] Fix the issue of going out of bounds in the isccfg
 parser.

This problem can occur when attempting to parse an empty file.
---
 .../el7toel8/libraries/isccfg.py              |  5 ++-
 .../el7toel8/libraries/tests/test_isccfg.py   | 32 +++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/repos/system_upgrade/el7toel8/libraries/isccfg.py b/repos/system_upgrade/el7toel8/libraries/isccfg.py
index 45baba0b..6cebb289 100644
--- a/repos/system_upgrade/el7toel8/libraries/isccfg.py
+++ b/repos/system_upgrade/el7toel8/libraries/isccfg.py
@@ -688,9 +688,12 @@ class IscConfigParser(object):
 
         while index != -1:
             keystart = index
-            while istr[index] in self.CHAR_KEYWORD and index < end_index:
+            while index < end_index and istr[index] in self.CHAR_KEYWORD:
                 index += 1
 
+            if index >= end_index:
+                break
+
             if keystart < index <= end_index and istr[index] not in self.CHAR_KEYWORD:
                 # key has been found
                 return ConfigSection(cfg, istr[keystart:index], keystart, index-1)
diff --git a/repos/system_upgrade/el7toel8/libraries/tests/test_isccfg.py b/repos/system_upgrade/el7toel8/libraries/tests/test_isccfg.py
index 7438fa37..00753681 100644
--- a/repos/system_upgrade/el7toel8/libraries/tests/test_isccfg.py
+++ b/repos/system_upgrade/el7toel8/libraries/tests/test_isccfg.py
@@ -116,6 +116,10 @@ view "v2" {
 };
 """)
 
+config_empty = isccfg.MockConfig('')
+
+config_empty_include = isccfg.MockConfig('options { include "/dev/null"; };')
+
 
 def check_in_section(parser, section, key, value):
     """ Helper to check some section was found
@@ -343,5 +347,33 @@ def test_walk():
     assert 'dnssec-validation' not in state
 
 
+def test_empty_config():
+    """ Test empty configuration """
+
+    callbacks = {}
+
+    parser = isccfg.IscConfigParser(config_empty)
+    assert len(parser.FILES_TO_CHECK) == 1
+    cfg = parser.FILES_TO_CHECK[0]
+    parser.walk(cfg.root_section(), callbacks)
+    assert cfg.buffer == ''
+
+
+def test_empty_include_config():
+    """ Test empty configuration """
+
+    callbacks = {}
+
+    parser = isccfg.IscConfigParser(config_empty_include)
+    assert len(parser.FILES_TO_CHECK) == 2
+    cfg = parser.FILES_TO_CHECK[0]
+    parser.walk(cfg.root_section(), callbacks)
+    assert cfg.buffer == 'options { include "/dev/null"; };'
+
+    null_cfg = parser.FILES_TO_CHECK[1]
+    parser.walk(null_cfg.root_section(), callbacks)
+    assert null_cfg.buffer == ''
+
+
 if __name__ == '__main__':
     test_key_views_lookaside()
-- 
2.41.0