diff --git a/apps/ll-driver-detect/src/driver_detection_config.cpp b/apps/ll-driver-detect/src/driver_detection_config.cpp
index daf06f297..74d8f786a 100644
--- a/apps/ll-driver-detect/src/driver_detection_config.cpp
+++ b/apps/ll-driver-detect/src/driver_detection_config.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2025 UnionTech Software Technology Co., Ltd.
+// SPDX-FileCopyrightText: 2025 - 2026 UnionTech Software Technology Co., Ltd.
 //
 // SPDX-License-Identifier: LGPL-3.0-or-later
 
@@ -64,6 +64,11 @@ bool DriverDetectionConfigManager::saveConfig()
     file << jsonConfig.dump(4); // Pretty print with 4 spaces
     file.close();
 
+    if (!file.good()) {
+        LogW("failed to write driver detection config to {}", configFilePath);
+        return false;
+    }
+
     return true;
 }
 
diff --git a/libs/linglong/tests/ll-tests/src/apps/ll-driver-detect/driver_detection_config_test.cpp b/libs/linglong/tests/ll-tests/src/apps/ll-driver-detect/driver_detection_config_test.cpp
index 042b228a0..8e891cd2d 100644
--- a/libs/linglong/tests/ll-tests/src/apps/ll-driver-detect/driver_detection_config_test.cpp
+++ b/libs/linglong/tests/ll-tests/src/apps/ll-driver-detect/driver_detection_config_test.cpp
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2025 UnionTech Software Technology Co., Ltd.
+ * SPDX-FileCopyrightText: 2026 UnionTech Software Technology Co., Ltd.
  *
  * SPDX-License-Identifier: LGPL-3.0-or-later
  */
@@ -69,3 +69,14 @@ TEST_F(DriverDetectionConfigTest, SaveAndLoadConfig)
     auto loadedConfig = manager2.getConfig();
     EXPECT_TRUE(loadedConfig.neverRemind);
 }
+
+TEST_F(DriverDetectionConfigTest, SaveConfigFailsOnWriteError)
+{
+    using namespace linglong::driver::detect;
+
+    // Opening /dev/full succeeds but every write fails with ENOSPC; if the
+    // device is unavailable the open itself fails, so the save must report
+    // failure either way instead of silently losing the user's choice
+    DriverDetectionConfigManager manager("/dev/full");
+    EXPECT_FALSE(manager.saveConfig());
+}