CVE-2020-25601

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchnreset / evtchndestroy. In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these when resetting all event channels or when cleaning...

CVE-2020-25601

CVE-2020-25601 (Xen) : A lack of preemption in evtchn_reset() and evtchn_destroy() inside the FIFO event channel model can cause a guest with many active event channels to stall the hypervisor, enabling a local attacker (malicious or buggy guest kernel) to mount a Denial of Service affecting the ...

CVE-2020-25601

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchnreset / evtchndestroy. In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these when resetting all event channels or when cleaning...

CVE-2020-25601

A security flaw was found in Xen. A lack of preemption in the FIFO event channel model may cause the CPU to spend an almost unbounded amount of processing time. This flaw allows malicious or buggy guest kernels to mount a denial of service DoS attack affecting the entire system. The highest threa...

lack of preemption in evtchn_reset() / evtchn_destroy()

ISSUE DESCRIPTION In particular the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these when resetting all event channels or when cleaning up after the guest may take extended periods of time. So far there was no arrangement for...

Memory corruption

fpregsstatevalid in arch/x86/include/asm/fpu/internal.h in the Linux kernel before 5.4.2, when GCC 9 is used, allows context-dependent attackers to cause a denial of service memory corruption or possibly have unspecified other impact because of incorrect fpufpregsownerctx caching, as demonstrated...

CVE-2019-19602

fpregsstatevalid in arch/x86/include/asm/fpu/internal.h in the Linux kernel before 5.4.2, when GCC 9 is used, allows context-dependent attackers to cause a denial of service memory corruption or possibly have unspecified other impact because of incorrect fpufpregsownerctx caching, as demonstrated...

UBUNTU-CVE-2019-19602

fpregsstatevalid in arch/x86/include/asm/fpu/internal.h in the Linux kernel before 5.4.2, when GCC 9 is used, allows context-dependent attackers to cause a denial of service memory corruption or possibly have unspecified other impact because of incorrect fpufpregsownerctx caching, as demonstrated...

CVE-2019-19602

fpregsstatevalid in arch/x86/include/asm/fpu/internal.h in the Linux kernel before 5.4.2, when GCC 9 is used, allows context-dependent attackers to cause a denial of service memory corruption or possibly have unspecified other impact because of incorrect fpufpregsownerctx caching, as demonstrated...

CVE-2019-19602

fpregsstatevalid in arch/x86/include/asm/fpu/internal.h in the Linux kernel before 5.4.2, when GCC 9 is used, allows context-dependent attackers to cause a denial of service memory corruption or possibly have unspecified other impact because of incorrect fpufpregsownerctx caching, as demonstrated...

Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested =1 virtualization is enabled. This high resolution timerhrtimer runs when a L2 guest is active. After VM exit, the syncvmcs12 timer object is stopped. The...

Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested =1 virtualization is enabled. This high resolution timerhrtimer runs when a L2 guest is active. After VM exit, the syncvmcs12 timer object is stopped. The...

NewStart CGSL CORE 5.05 / MAIN 5.05 : kernel Multiple Vulnerabilities (NS-SA-2019-0085)

The remote NewStart CGSL host, running version CORE 5.05 / MAIN 5.05, has kernel packages installed that are affected by multiple vulnerabilities: - A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested =1...

CISCO Small Business Switches Multiple Redirect Vulnerability

Cisco Small Business 200 Series Managed Switches and so on are the products of the American Cisco Cisco company.Cisco Small Business 200 Series Managed Switches is a 200 Series Managed Switch.Cisco?Small Business 300 Series Managed Switches is a 300 Series Managed Switch.Cisco?Small Business 500...

Linux - Use-After-Free via race Between modify_ldt() and #BR Exception

Linux - Use-After-Free via race Between modifyldt and BR Exception / When a BR exception is raised because of an MPX bounds violation, Linux parses the faulting instruction and computes the linear address of its memory operand. If the userspace instruction is in 32-bit code, this involves looking...

Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested =1 virtualization is enabled. This high resolution timerhrtimer runs when a L2 guest is active. After VM exit, the syncvmcs12 timer object is stopped. The...

Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested =1 virtualization is enabled. This high resolution timerhrtimer runs when a L2 guest is active. After VM exit, the syncvmcs12 timer object is stopped. The...

Important: kernel

Issue Overview: A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor implements its device control API. While creating a device via kvmioctlcreatedevice, the device holds a reference to a VM object, later this reference is transferred to the caller's file descript...

CVE-2019-7221

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested =1 virtualization is enabled. This high resolution timerhrtimer runs when a L2 guest is active. After VM exit, the syncvmcs12 timer object is stopped. The...

Fedora 28 : xen (2018-a7862a75f5)

preemption checks bypassed in x86 PV MM handling XSA-264, CVE-2018-12891 1595959 x86: DB exception safety check can be triggered by a guest XSA-265, CVE-2018-12893 1595958 libxl fails to honour readonly flag on HVM emulated SCSI disks XSA-266, CVE-2018-12892 1595957 Note that Tenable Network...