Multiple race conditions in ipc/shm.c in the Linux kernel before 3.12.2 allow local users to cause a denial of service (use-after-free and system crash) or possibly have unspecified other impact via a crafted application that uses shmctl IPC_RMID operations in conjunction with other shm system calls.
http://www.ubuntu.com/usn/USN-2075-1
http://www.ubuntu.com/usn/USN-2070-1
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.12.2