Debian Security Advisory

DLA-479-1 xen -- LTS security update

Date Reported:
17 May 2016
Affected Packages:
xen
Vulnerable:
Yes
Security database references:
In Mitre's CVE dictionary: CVE-2015-2752, CVE-2015-2756, CVE-2015-5165, CVE-2015-5307, CVE-2015-7969, CVE-2015-7970, CVE-2015-7971, CVE-2015-7972, CVE-2015-8104, CVE-2015-8339, CVE-2015-8340, CVE-2015-8550, CVE-2015-8554, CVE-2015-8555, CVE-2015-8615, CVE-2016-1570, CVE-2016-1571, CVE-2016-2270, CVE-2016-2271.
More information:

This security update fixes a number of security issues in Xen in wheezy.

For Debian 7 Wheezy, these problems have been fixed in version 4.1.6.1-1+deb7u1.

We recommend that you upgrade your libidn packages.

  • CVE-2015-2752

    The XEN_DOMCTL_memory_mapping hypercall in Xen 3.2.x through 4.5.x, when using a PCI passthrough device, is not preemptable, which allows local x86 HVM domain users to cause a denial of service (host CPU consumption) via a crafted request to the device model (qemu-dm).

  • CVE-2015-2756

    QEMU, as used in Xen 3.3.x through 4.5.x, does not properly restrict access to PCI command registers, which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device, which triggers an Unsupported Request (UR) response.

  • CVE-2015-5165

    The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used in Xen 4.5.x and earlier, allows remote attackers to read process heap memory via unspecified vectors.

  • CVE-2015-5307

    The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a denial of service (host OS panic or hang) by triggering many #AC (aka Alignment Check) exceptions, related to svm.c and vmx.c.

  • CVE-2015-7969

    Multiple memory leaks in Xen 4.0 through 4.6.x allow local guest administrators or domains with certain permission to cause a denial of service (memory consumption) via a large number of teardowns of domains with the vcpu pointer array allocated using the (1) XEN_DOMCTL_max_vcpus hypercall or the xenoprofile state vcpu pointer array allocated using the (2) XENOPROF_get_buffer or (3) XENOPROF_set_passive hypercall.

  • CVE-2015-7970

    The p2m_pod_emergency_sweep function in arch/x86/mm/p2m-pod.c in Xen 3.4.x, 3.5.x, and 3.6.x is not preemptible, which allows local x86 HVM guest administrators to cause a denial of service (CPU consumption and possibly reboot) via crafted memory contents that triggers a "time-consuming linear scan," related to Populate-on-Demand.

  • CVE-2015-7971

    Xen 3.2.x through 4.6.x does not limit the number of printk console messages when logging certain pmu and profiling hypercalls, which allows local guests to cause a denial of service via a sequence of crafted (1) HYPERCALL_xenoprof_op hypercalls, which are not properly handled in the do_xenoprof_op function in common/xenoprof.c, or (2) HYPERVISOR_xenpmu_op hypercalls, which are not properly handled in the do_xenpmu_op function in arch/x86/cpu/vpmu.c.

  • CVE-2015-7972

    The (1) libxl_set_memory_target function in tools/libxl/libxl.c and (2) libxl__build_post function in tools/libxl/libxl_dom.c in Xen 3.4.x through 4.6.x do not properly calculate the balloon size when using the populate-on-demand (PoD) system, which allows local HVM guest users to cause a denial of service (guest crash) via unspecified vectors related to "heavy memory pressure."

  • CVE-2015-8104

    The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a denial of service (host OS panic or hang) by triggering many #DB (aka Debug) exceptions, related to svm.c.

  • CVE-2015-8339

    The memory_exchange function in common/memory.c in Xen 3.2.x through 4.6.x does not properly hand back pages to a domain, which might allow guest OS administrators to cause a denial of service (host crash) via unspecified vectors related to domain teardown.

  • CVE-2015-8340

    The memory_exchange function in common/memory.c in Xen 3.2.x through 4.6.x does not properly release locks, which might allow guest OS administrators to cause a denial of service (deadlock or host crash) via unspecified vectors, related to XENMEM_exchange error handling.

  • CVE-2015-8550

    Xen, when used on a system providing PV backends, allows local guest OS administrators to cause a denial of service (host OS crash) or gain privileges by writing to memory shared between the frontend and backend, aka a double fetch vulnerability.

  • CVE-2015-8554

    Buffer overflow in hw/pt-msi.c in Xen 4.6.x and earlier, when using the qemu-xen-traditional (aka qemu-dm) device model, allows local x86 HVM guest administrators to gain privileges by leveraging a system with access to a passed-through MSI-X capable physical PCI device and MSI-X table entries, related to a "write path."

  • CVE-2015-8555

    Xen 4.6.x, 4.5.x, 4.4.x, 4.3.x, and earlier do not initialize x86 FPU stack and XMM registers when XSAVE/XRSTOR are not used to manage guest extended register state, which allows local guest domains to obtain sensitive information from other domains via unspecified vectors.

  • CVE-2015-8615

    The hvm_set_callback_via function in arch/x86/hvm/irq.c in Xen 4.6 does not limit the number of printk console messages when logging the new callback method, which allows local HVM guest OS users to cause a denial of service via a large number of changes to the callback method (HVM_PARAM_CALLBACK_IRQ).

  • CVE-2016-1570

    The PV superpage functionality in arch/x86/mm.c in Xen 3.4.0, 3.4.1, and 4.1.x through 4.6.x allows local PV guests to obtain sensitive information, cause a denial of service, gain privileges, or have unspecified other impact via a crafted page identifier (MFN) to the (1) MMUEXT_MARK_SUPER or (2) MMUEXT_UNMARK_SUPER sub-op in the HYPERVISOR_mmuext_op hypercall or (3) unknown vectors related to page table updates.

  • CVE-2016-1571

    The paging_invlpg function in include/asm-x86/paging.h in Xen 3.3.x through 4.6.x, when using shadow mode paging or nested virtualization is enabled, allows local HVM guest users to cause a denial of service (host crash) via a non-canonical guest address in an INVVPID instruction, which triggers a hypervisor bug check.

  • CVE-2016-2270

    Xen 4.6.x and earlier allows local guest administrators to cause a denial of service (host reboot) via vectors related to multiple mappings of MMIO pages with different cachability settings.

  • CVE-2016-2271

    VMX in Xen 4.6.x and earlier, when using an Intel or Cyrix CPU, allows local HVM guest users to cause a denial of service (guest crash) via vectors related to a non-canonical RIP.