PT-2016-3936

Name of the Vulnerable Software and Affected Versions Xen version 4.6 Description The issue allows local HVM guest OS users to cause a denial of service by making a large number of changes to the callback method, resulting in an excessive number of printk console messages. This occurs due to the...

FreeBSD : xen-kernel -- ioreq handling possibly susceptible to multiple read issue (6aa2d135-b40e-11e5-9728-002590263bf5)

The Xen Project reports : Single memory accesses in source code can be translated to multiple ones in machine code by the compiler, requiring special caution when accessing shared memory. Such precaution was missing from the hypervisor code inspecting the state of I/O requests sent to the device...

Xen 'hvm/irq.c' Denial of Service Vulnerability

Xen is an open source virtual machine monitor product developed at the University of Cambridge, UK. The product enables different and incompatible operating systems to run on the same computer and supports runtime migration to ensure uptime and avoid downtime. A denial of service vulnerability...

ioreq handling possibly susceptible to multiple read issue

ISSUE DESCRIPTION Single memory accesses in source code can be translated to multiple ones in machine code by the compiler, requiring special caution when accessing shared memory. Such precaution was missing from the hypervisor code inspecting the state of I/O requests sent to the device model fo...

Citrix XenServer Security Update for CVE-2015-5307 and CVE-2015-8104 (CTX202583)

A security vulnerability has been identified in Citrix XenServer that may allow a malicious administrator of an HVM guest VM to crash the host. This vulnerability affects all currently supported versions of Citrix XenServer up to and including Citrix XenServer 6.5 Service Pack 1...

WITHDRAWN: missing XSETBV intercept privilege check on AMD SVM

ISSUE DESCRIPTION NOTE: This advisory has been withdrawn XSETBV is a privileged instruction, i.e. should result in GP when issued by code running at other than the most privileged level CPL 0. Unlike other privileged and intercepted instructions in AMD SVM, XSETBV has the privilege level check do...

FreeBSD : xen-kernel -- Long latency populate-on-demand operation is not preemptible (83350009-881e-11e5-ab94-002590263bf5)

The Xen Project reports : When running an HVM domain in Populate-on-Demand mode, Xen would sometimes search the domain for memory to reclaim, in response to demands for population of other pages in the same domain. This search runs without preemption. The guest can, by suitable arrangement of its...

x86: CPU lockup during exception delivery

ISSUE DESCRIPTION When a benign exception occurs while delivering another benign exception, it is architecturally specified that these would be delivered sequentially. There are, however, cases where this results in an infinite loop inside the CPU, which in the virtualized case can be broken only...

xen-kernel -- CPU lockup during exception delivery

The Xen Project reports: A malicious HVM guest administrator can cause a denial of service. Specifically, prevent use of a physical CPU for a significant, perhaps indefinite period. If a host watchdog Xen or dom0 is in use, this can lead to a watchdog timeout and consequently a reboot of the host...

Xen Denial of Service Vulnerability (CNVD-2015-07433)

Xen is an open source virtual machine monitor product. Xen has a security vulnerability that allows an attacker with HVM virtual machine access to crash the system and perform denial of service attacks...

CVE-2015-7972

The 1 libxlsetmemorytarget function in tools/libxl/libxl.c and 2 libxlbuildpost function in tools/libxl/libxldom.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...

CVE-2015-7972

The 1 libxlsetmemorytarget function in tools/libxl/libxl.c and 2 libxlbuildpost function in tools/libxl/libxldom.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...

CVE-2015-7970

The p2mpodemergencysweep 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,"...

CVE-2015-7972

The 1 libxlsetmemorytarget function in tools/libxl/libxl.c and 2 libxlbuildpost function in tools/libxl/libxldom.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...

CVE-2015-7970

The p2mpodemergencysweep 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,"...

CVE-2015-7972

The 1 libxlsetmemorytarget function in tools/libxl/libxl.c and 2 libxlbuildpost function in tools/libxl/libxldom.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...

CVE-2015-7970: Undefined Security Weakness

The p2mpodemergencysweep 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,"...

PT-2015-7683

Name of the Vulnerable Software and Affected Versions Xen versions 3.4.x through 3.6.x Description The issue is related to the p2m pod emergency sweep function in Xen, which is not preemptible. This allows local x86 HVM guest administrators to cause a denial of service by consuming CPU resources...

x86: Long latency populate-on-demand operation is not preemptible

ISSUE DESCRIPTION When running an HVM domain in Populate-on-Demand mode, Xen would sometimes search the domain for memory to reclaim, in response to demands for population of other pages in the same domain. This search runs without preemption. The guest can, by suitable arrangement of its memory...

x86: populate-on-demand balloon size inaccuracy can crash guests

ISSUE DESCRIPTION The design of the memory populate-on-demand PoD system requires that a guest's memory ballooning driver reach its memory reduction target. The target is not entirely well-defined in terms of the information visible to the appropriate parts of the system, so some unknown set of...