grant-table: double version change race

ISSUE DESCRIPTION XSA-501 was about issues with v1 - v2 and v2 - v1 changes racing certain other grant table operations. Sadly a v2 - v1 - v2 change has yet another effect which wasn't accounted for: During the first change, status pages would be freed. During the second change they would be...

EUVD-2018-4844

Malware in sbrugna...

Design/Logic Flaw

An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions...

CVE-2018-12891

An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions...

CVE-2018-12891: Undefined Security Weakness

An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions...

CVE-2018-12891

An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions...

preemption checks bypassed in x86 PV MM handling

ISSUE DESCRIPTION Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions through its own page table...