漏洞信息
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Vulnerability Title
top-level shadow reference dropped too early for 64-bit PV guests
Vulnerability Description
For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. Since Xen itself needs to be mapped when PV guests run, Xen and shadowed PV guests run directly the respective shadow page tables. For 64-bit PV guests this means running on the shadow of the guest root page table. In the course of dealing with shortage of memory in the shadow pool associated with a domain, shadows of page tables may be torn down. This tearing down may include the shadow root page table that the CPU in question is presently running on. While a precaution exists to supposedly prevent the tearing down of the underlying live page table, the time window covered by that precaution isn't large enough.
CVSS Information
N/A
Vulnerability Type
N/A
Vulnerability Title
Xen 安全漏洞
Vulnerability Description
Xen是英国剑桥（Cambridge）大学的一款开源的虚拟机监视器产品。该产品能够使不同和不兼容的操作系统运行在同一台计算机上，并支持在运行时进行迁移，保证正常运行并且避免宕机。 Xen存在安全漏洞，该漏洞源于在处理shadow memory不足过程中与域相关联的页表的shadow可能会被拆除，这拆除可能包括CPU所在的shadow page。
CVSS Information
N/A
Vulnerability Type
N/A