Ubuntu Security Notice 518-1 – Evan Teran discovered that the Linux kernel ptrace routines did not correctly handle certain requests robustly. Local attackers could exploit this to crash the system, causing a denial of service. It was discovered that hugetlb kernels on PowerPC systems did not prevent the stack from colliding with reserved kernel memory. Local attackers could exploit this and crash the system, causing a denial of service. It was discovered that certain CIFS filesystem actions did not honor the umask of a process. Local attackers could exploit this to gain additional privileges. Wojciech Purczynski discovered that the Linux kernel ia32 syscall emulation in x86_64 kernels did not correctly clear the high bits of registers. Local attackers could exploit this to gain root privileges.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/59589/USN-518-1.txt
Source: https://packetstormsecurity.com/files/59589/Ubuntu-Security-Notice-518-1.html