kvm-83-249.0.1.AXS3

KVM (for Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware.

Using KVM, one can run multiple virtual machines running unmodified Linux or Windows images. Each virtual machine has private virtualized hardware: a network card, disk, graphics adapter, etc.

Security issues fixed with this release:

• CVE-2011-4622
The create_pit_timer function in arch/x86/kvm/i8254.c in KVM 83, and possibly other versions, does not properly handle when Programmable Interval Timer (PIT) interrupt requests (IRQs) when a virtual interrupt controller (irqchip) is not available, which allows local users to cause a denial of service (NULL pointer dereference) by starting a timer.

• CVE-2011-0029
Heap-based buffer overflow in the process_tx_desc function in the e1000 emulation (hw/e1000.c) in qemu-kvm 0.12, and possibly other versions, allows guest OS users to cause a denial of service (QEMU crash) and possibly execute arbitrary code via crafted legacy mode packets.

• CVE-2011-4347
No information available at the time of writing, please refer to the CVE the links below.

Fixed bugs:

• Previously, if the virtual CPU affinity was set, asynchronous I/O threads, created by threads of the virtual CPU, inherited the affinity and could make a guest VM unresponsive, unable to reboot or shut down, with the following message:

INFO: task insmod:426 blocked for more than 120 seconds. ”echo 0 > /proc/sys/kernel/hung_task_timeout_secs” disables this message.

Asynchronous I/O threads are now created by the main thread and inherit the main thread affinity; VMs do not become unstable anymore.