In the Linux kernel, the following vulnerability has been resolved:

timers/itimer: Zero-init old itimerval before copy to userspace

On native sparc64, struct kernel old timeval contains a four-byte hole after tv usec because tv sec is 64-bit while kernel suseconds t is 32-bit. put itimerval() fills only the named fields in a stack-allocated kernel old itimerval and copies the entire object to userspace, so getitimer() can expose the two padding holes.

Zero-initialize the aggregate before assigning the fields so implicit padding is deterministic before it crosses the user/kernel boundary.