When using O_CREAT, the mode should be specified.

Change-Id: Id364072fce62388eba47207a97800eb185480633

core/jni/android_server_Watchdog.cpp

@@ -17,6 +17,7 @@
 #define LOG_TAG "Watchdog_N"
 #include <utils/Log.h>
 
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
 #include <dirent.h>
@@ -63,7 +64,7 @@ static void dumpKernelStacks(JNIEnv* env, jobject clazz, jstring pathStr) {
 
     const char *path = env->GetStringUTFChars(pathStr, NULL);
 
-    int outFd = open(path, O_WRONLY | O_APPEND | O_CREAT);
+    int outFd = open(path, O_WRONLY | O_APPEND | O_CREAT, S_IWUSR);
     if (outFd < 0) {
         LOGE("Unable to open stack dump file: %d (%s)", errno, strerror(errno));
         goto done;