[ALAS-2012-55] Amazon Linux - ALAS-2012-55: medium priority package update for kernel

Package updates are available for Amazon Linux that fix the following vulnerabilities:
CVE-2012-0207:
* A divide-by-zero flaw was found in the Linux kernel's igmp_heard_query() function. An attacker able to send certain IGMP (Internet Group Management Protocol) packets to a target system could use this flaw to cause a denial of service.

CVE-2012-0045:
* A flaw was found in the way the Linux kernel's KVM hypervisor implementation emulated the syscall instruction for 32-bit guests. An unprivileged guest user could trigger this flaw to crash the guest.

CVE-2012-0038:
* A flaw was found in the way the Linux kernel's XFS file system implementation handled on-disk Access Control Lists (ACLs). A local, unprivileged user could use this flaw to cause a denial of service or escalate their privileges by mounting a specially-crafted disk.

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.
A flaw was found in the way the KVM subsystem of a Linux kernel handled PIT (Programmable Interval Timer) IRQs (interrupt requests) when there was no virtual interrupt controller set up. A malicious user in the kvm group on the host could force this situation to occur, resulting in the host crashing.
* A flaw was found in the way the KVM subsystem of a Linux kernel handled PIT (Programmable Interval Timer) IRQs (interrupt requests) when there was no virtual interrupt controller set up. A local, unprivileged user on the host could force this situation to occur, resulting in the host crashing.

CVE-2011-4611:
* The RHSA-2011:1530 kernel update introduced an integer overflow flaw in the Linux kernel. On PowerPC systems, a local, unprivileged user could use this flaw to cause a denial of service.

CVE-2011-4594:
* Two flaws were found in the way the Linux kernel's __sys_sendmsg() function, when invoked via the sendmmsg() system call, accessed user-space memory. A local, unprivileged user could use these flaws to cause a denial of service.

CVE-2011-4347:
It was found that the kvm_vm_ioctl_assign_device() function in the KVM subsystem of a Linux kernel did not check if the user requesting device assignment was privileged or not. A member of the kvm group on the host could assign unused PCI devices, or even devices that were in use and whose resources were not properly claimed by the respective drivers, which could result in the host crashing.
* It was found that the kvm_vm_ioctl_assign_device() function in the KVM (Kernel-based Virtual Machine) subsystem of a Linux kernel did not check if the user requesting device assignment was privileged or not. A local, unprivileged user on the host could assign unused PCI devices, or even devices that were in use and whose resources were not properly claimed by the respective drivers, which could result in the host crashing.

CVE-2011-4132:
* A flaw was found in the Linux kernel's Journaling Block Device (JBD). A local, unprivileged user could use this flaw to crash the system by mounting a specially-crafted ext3 or ext4 disk.
* A flaw was found in the Linux kernel's Journaling Block Device (JBD). A local attacker could use this flaw to crash the system by mounting a specially-crafted ext3 or ext4 disk.

CVE-2011-4081:
* Flaws in ghash_update() and ghash_final() could allow a local, unprivileged user to cause a denial of service.

CVE-2011-4077:
* A buffer overflow flaw was found in the way the Linux kernel's XFS file system implementation handled links with overly long path names. A local, unprivileged user could use this flaw to cause a denial of service or escalate their privileges by mounting a specially-crafted disk.