The Linux kernel before 3.15.4 on Intel processors does not properly restrict use of a non-canonical value for the saved RIP address in the case of a system call that does not use IRET, which allows local users to leverage a race condition and gain privileges, or cause a denial of service (double fault), via a crafted application that makes ptrace and fork system calls.

Affected: Ubuntu:14.04:LTS: linux

Andy Lutomirski discovered a flaw with the Linux kernel's ptrace syscall on x86_64 processors. An attacker could exploit this flaw to cause a denial of service (System Crash) or potential gain administrative privileges.