Local kernel memory corruption via devfreq statistics read

Buffer overflow in Linux kernel 3.8 and later allows local users to corrupt kernel memory by reading a devfreq trans_stat file. The trans_stat_show function repeatedly appends transition-table rows with snprintf without stopping when its PAGE_SIZE sysfs buffer is full, so later writes extend past the allocation. Any unprivileged local user able to read the exposed attribute can trigger the overflow, leading to kernel memory disclosure, code execution, or a crash.