Ubuntu Security Notice 2843-1 – Jan Beulich discovered that the KVM svm hypervisor implementation in the Linux kernel did not properly catch Debug exceptions on AMD processors. An attacker in a guest virtual machine could use this to cause a denial of service (system crash) in the host OS. It was discovered that the ppp implementation in the Linux kernel did not ensure that certain slot numbers are valid. A local attacker with the privilege to call ioctl() on /dev/ppp could cause a denial of service (system crash). Various other issues were also addressed.