config: Hardened config logic against Time-Of-Check race conditions (#11368)

1 files changed, 31 insertions, 24 deletions

diff --git a/src/config/ConfigManager.cpp b/src/config/ConfigManager.cpp
index 48c1d103..d6a0b7d4 100644
--- a/src/config/ConfigManager.cpp
+++ b/src/config/ConfigManager.cpp
@@ -873,11 +873,15 @@ CConfigManager::CConfigManager() {
 std::optional<std::string> CConfigManager::generateConfig(std::string configPath) {
     std::string parentPath = std::filesystem::path(configPath).parent_path();
 
-    if (!std::filesystem::is_directory(parentPath)) {
-        Debug::log(WARN, "Creating config home directory");
-        try {
-            std::filesystem::create_directories(parentPath);
-        } catch (std::exception& e) { throw e; }
+    if (!parentPath.empty()) {
+        std::error_code ec;
+        bool            created = std::filesystem::create_directories(parentPath, ec);
+        if (ec) {
+            Debug::log(ERR, "Couldn't create config home directory ({}): {}", ec.message(), parentPath);
+            return "Config could not be generated.";
+        }
+        if (created)
+            Debug::log(WARN, "Creating config home directory");
     }
 
     Debug::log(WARN, "No config file found; attempting to generate.");
@@ -886,7 +890,7 @@ std::optional<std::string> CConfigManager::generateConfig(std::string configPath
     ofs << AUTOGENERATED_PREFIX << EXAMPLE_CONFIG;
     ofs.close();
 
-    if (!std::filesystem::exists(configPath))
+    if (ofs.fail())
         return "Config could not be generated.";
 
     return configPath;
@@ -3040,28 +3044,31 @@ std::optional<std::string> CConfigManager::handleSource(const std::string& comma
     std::string errorsFromParsing;
 
     for (size_t i = 0; i < glob_buf->gl_pathc; i++) {
-        auto value = absolutePath(glob_buf->gl_pathv[i], m_configCurrentPath);
+        auto            value = absolutePath(glob_buf->gl_pathv[i], m_configCurrentPath);
 
-        if (!std::filesystem::is_regular_file(value)) {
-            if (std::filesystem::exists(value)) {
-                Debug::log(WARN, "source= skipping non-file {}", value);
-                continue;
-            }
+        std::error_code ec;
+        auto            file_status = std::filesystem::status(value, ec);
 
-            Debug::log(ERR, "source= file doesn't exist: {}", value);
-            return "source= file " + value + " doesn't exist!";
+        if (ec) {
+            Debug::log(ERR, "source= file from glob result is inaccessible ({}): {}", ec.message(), value);
+            return "source= file " + value + " is inaccessible!";
         }
-        m_configPaths.emplace_back(value);
-
-        auto configCurrentPathBackup = m_configCurrentPath;
-        m_configCurrentPath          = value;
-
-        const auto THISRESULT = m_config->parseFile(value.c_str());
 
-        m_configCurrentPath = configCurrentPathBackup;
-
-        if (THISRESULT.error && errorsFromParsing.empty())
-            errorsFromParsing += THISRESULT.getError();
+        if (std::filesystem::is_regular_file(file_status)) {
+            m_configPaths.emplace_back(value);
+            auto configCurrentPathBackup = m_configCurrentPath;
+            m_configCurrentPath          = value;
+            const auto THISRESULT        = m_config->parseFile(value.c_str());
+            m_configCurrentPath          = configCurrentPathBackup;
+            if (THISRESULT.error && errorsFromParsing.empty())
+                errorsFromParsing += THISRESULT.getError();
+        } else if (std::filesystem::is_directory(file_status)) {
+            Debug::log(WARN, "source= skipping directory {}", value);
+            continue;
+        } else {
+            Debug::log(WARN, "source= skipping non-regular-file {}", value);
+            continue;
+        }
     }
 
     if (errorsFromParsing.empty())