CVE-2012-4461

El subsistema de KVM en el kernel de Linux antes de v3.6.9, cuando se ejecuta en máquinas que utilizan el espacio de usuario qemu sin XSAVE, permite a usuarios locales provocar una denegación de servicio (kernel oops) mediante la KVM_SET_SREGS ioctl para establecer el bit X86_CR4_OSXSAVE en el huésped registro cr4 , y luego llamar a la KVM_RUN ioctl.

USN-1704-1 fixed vulnerabilities in the Linux kernel. Due to an unrelated regression inotify/fanotify stopped working after upgrading. This update fixes the problem. Brad Spengler discovered a flaw in the Linux kernel's uname system call. An unprivileged user could exploit this flaw to read kernel stack memory. Jon Howell reported a flaw in the Linux kernel's KVM (Kernel-based virtual machine) subsystem's handling of the XSAVE feature. On hosts, using qemu userspace, without the XSAVE feature an unprivileged local attacker could exploit this flaw to crash the system. Dmitry Monakhov reported a race condition flaw the Linux ext4 filesystem that can expose stale data. An unprivileged user could exploit this flaw to cause an information leak. A flaw was discovered in the Linux kernel's handling of script execution when module loading is enabled. A local attacker could exploit this flaw to cause a leak of kernel stack contents. Rodrigo Freire discovered a flaw in the Linux kernel's TCP illinois congestion control algorithm. A local attacker could use this to cause a denial of service. A flaw was discovered in the Linux kernel's handling of new hot-plugged memory. An unprivileged local user could exploit this flaw to cause a denial of service by crashing the system. Florian Weimer discovered that hypervkvpd, which is distributed in the Linux kernel, was not correctly validating source addresses of netlink packets. An untrusted local user can cause a denial of service by causing hypervkvpd to exit. Various other issues were also addressed.