abrt: ChownProblemDir succeeds during active post-create event processing due to inadequate locking

A race condition was found in the abrt-dbus D-Bus service's ChownProblemDir method. ChownProblemDir opens the dump directory with DDOPENREADONLY and calls ddchown to change ownership of all files to the caller's uid, succeeding even while post-create event handlers hold a write lock. This allows ...