CVE-2015-4164

This xen update is based on upstream 4.5.2 maintenance release, and fixes the following security issues:

The vgic_v2_to_sgi function in arch/arm/vgic-v2.c in Xen 4.5.x, when running on ARM hardware with general interrupt controller (GIC) version 2, allows local guest users to cause a denial of service (host crash) by writing an invalid value to the GICD.SGIR register (CVE-2015-0268).

The ARM GIC distributor virtualization in Xen 4.4.x and 4.5.x allows local guests to cause a denial of service by causing a large number messages to be logged (CVE-2015-1563).

The emulation routines for unspecified X86 devices in Xen 3.2.x through 4.5.x does not properly initialize data, which allow local HVM guest users to obtain sensitive information via vectors involving an unsupported access size (CVE-2015-2044).

The HYPERVISOR_xen_version hypercall in Xen 3.2.x through 4.5.x does not properly initialize data structures, which allows local guest users to obtain sensitive information via unspecified vectors (CVE-2015-2045).

Xen 3.3.x through 4.5.x and the Linux kernel through 3.19.1 do not properly restrict access to PCI command registers, which might allow local 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-2015-2150).

The x86 emulator in Xen 3.2.x through 4.5.x does not properly ignore segment overrides for instructions with register operands, which allows local guest users to obtain sensitive information, cause a denial of service (memory corruption), or possibly execute arbitrary code via unspecified vectors (CVE-2015-2151).

Xen 4.5.x and earlier enables certain default backends when emulating a VGA device for an x86 HVM guest qemu even when the configuration disables them, which allows local guest users to obtain access to the VGA console by (1) setting the DISPLAY environment variable, when compiled with SDL support, or connecting to the VNC server on (2) ::1 or (3) 127.0.0.1, when not compiled with SDL support (CVE-2015-2152).

Xen 4.3.x, 4.4.x, and 4.5.x, when using toolstack disaggregation, allows remote domains with partial management control to cause a denial of service (host lock) via unspecified domctl operations (CVE-2015-2751).

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-2015-2752).

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-2015-2756).

Heap-based buffer overflow in the PCNET controller in QEMU allows remote attackers to execute arbitrary code by sending a packet with TXSTATUS_STARTPACKET set and then a crafted packet with TXSTATUS_DEVICEOWNS set (CVE-2015-3209).

Stack-based buffer overflow in the xl command line utility in Xen 4.1.x through 4.5.x allows local guest administrators to gain privileges via a long configuration argument (CVE-2015-3259).

Xen 4.2.x through 4.5.x does not initialize certain fields, which allows certain remote service domains to obtain sensitive information from memory via a (1) XEN_DOMCTL_gettscinfo or (2) XEN_SYSCTL_getdomaininfolist request (CVE-2015-3340).

The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other…

Xen was updated to fix seven security issues and one non-security bug.

The following vulnerabilities were fixed:

• CVE-2015-4103: Potential unintended writes to host MSI message data field via qemu (XSA-128) (bnc#931625)
• CVE-2015-4104: PCI MSI mask bits inadvertently exposed to guests (XSA-129) (bnc#931626)
• CVE-2015-4105: Guest triggerable qemu MSI-X pass-through error messages (XSA-130) (bnc#931627)
• CVE-2015-4106: Unmediated PCI register access in qemu (XSA-131) (bnc#931628)
• CVE-2015-4163: GNTTABOP_swap_grant_ref operation misbehavior (XSA-134) (bnc#932790)
• CVE-2015-3209: heap overflow in qemu pcnet controller allowing guest to host escape (XSA-135) (bnc#932770)
• CVE-2015-4164: DoS through iret hypercall handler (XSA-136) (bnc#932996)

The following non-security bug was fixed:

• bnc#906689: let systemd schedule xencommons after network-online.target and remote-fs.target so that xendomains has access to remote shares

Xen was updated to fix seven security vulnerabilities:

* CVE-2015-4103: Potential unintended writes to host MSI message data
  field via qemu. (XSA-128, bnc#931625)
* CVE-2015-4104: PCI MSI mask bits inadvertently exposed to guests.
  (XSA-129, bnc#931626)
* CVE-2015-4105: Guest triggerable qemu MSI-X pass-through error
  messages. (XSA-130, bnc#931627)
* CVE-2015-4106: Unmediated PCI register access in qemu. (XSA-131,
  bnc#931628)
* CVE-2015-4163: GNTTABOP_swap_grant_ref operation misbehavior.
  (XSA-134, bnc#932790)
* CVE-2015-3209: Heap overflow in qemu pcnet controller allowing guest
  to host escape. (XSA-135, bnc#932770)
* CVE-2015-4164: DoS through iret hypercall handler. (XSA-136,
  bnc#932996)

Security Issues:

* CVE-2015-4103
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4103>
* CVE-2015-4104
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4104>
* CVE-2015-4105
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4105>
* CVE-2015-4106
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4106>
* CVE-2015-4163
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4163>
* CVE-2015-4164
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4164>
* CVE-2015-3209
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3209>

Xen was updated to fix six security issues:

* CVE-2015-4103: Potential unintended writes to host MSI message data
  field via qemu. (XSA-128, bsc#931625)
* CVE-2015-4104: PCI MSI mask bits inadvertently exposed to guests.
  (XSA-129, bsc#931626)
* CVE-2015-4105: Guest triggerable qemu MSI-X pass-through error
  messages. (XSA-130, bsc#931627)
* CVE-2015-4106: Unmediated PCI register access in qemu. (XSA-131,
  bsc#931628)
* CVE-2015-3209: heap overflow in qemu pcnet controller allowing guest
  to host escape. (XSA-135, bsc#932770)
* CVE-2015-4164: DoS through iret hypercall handler. (XSA-136,
  bsc#932996)

Security Issues:

* CVE-2015-4103
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4103>
* CVE-2015-4104
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4104>
* CVE-2015-4105
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4105>
* CVE-2015-4106
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4106>
* CVE-2015-4164
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4164>
* CVE-2015-3209
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3209>

Xen was updated to fix six security issues:

* CVE-2015-4103: Potential unintended writes to host MSI message data
  field via qemu. (XSA-128, bsc#931625)
* CVE-2015-4104: PCI MSI mask bits inadvertently exposed to guests.
  (XSA-129, bsc#931626)
* CVE-2015-4105: Guest triggerable qemu MSI-X pass-through error
  messages. (XSA-130, bsc#931627)
* CVE-2015-4106: Unmediated PCI register access in qemu. (XSA-131,
  bsc#931628)
* CVE-2015-3209: Heap overflow in qemu pcnet controller allowing guest
  to host escape. (XSA-135, bsc#932770)
* CVE-2015-4164: DoS through iret hypercall handler. (XSA-136,
  bsc#932996)

Security Issues:

* CVE-2015-4103
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4103>
* CVE-2015-4104
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4104>
* CVE-2015-4105
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4105>
* CVE-2015-4106
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4106>
* CVE-2015-4163
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4163>
* CVE-2015-4164
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-4164>
* CVE-2015-3209
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3209>

xen was updated to fix the following security issues:

• CVE-2015-5165: QEMU leak of uninitialized heap memory in rtl8139 device model (bsc#939712, XSA-140)
• CVE-2015-5166: Use after free in QEMU/Xen block unplug protocol (bsc#939709, XSA-139)
• CVE-2015-2751: Certain domctl operations could have be used to lock up the host (bsc#922709, XSA-127)
• CVE-2015-3259: xl command line config handling stack overflow (bsc#935634, XSA-137)
• CVE-2015-4164: DoS through iret hypercall handler (bsc#932996, XSA-136)
• CVE-2015-5154: Host code execution via IDE subsystem CD-ROM (bsc#938344)

xen was updated to fix the following security issues:

• CVE-2015-5165: QEMU leak of uninitialized heap memory in rtl8139 device model (bsc#939712, XSA-140)
• CVE-2015-5166: Use after free in QEMU/Xen block unplug protocol (bsc#939709, XSA-139)
• CVE-2015-2751: Certain domctl operations could have be used to lock up the host (bsc#922709, XSA-127)
• CVE-2015-3259: xl command line config handling stack overflow (bsc#935634, XSA-137)
• CVE-2015-4164: DoS through iret hypercall handler (bsc#932996, XSA-136)
• CVE-2015-5154: Host code execution via IDE subsystem CD-ROM (bsc#938344)

The compat_iret function in Xen 3.1 through 4.5 iterates the wrong way through a loop, which allows local 32-bit PV guest administrators to cause a denial of service (large loop and system hang) via a hypercall_iret call with EFLAGS.VM set.