CVE-2021-3308

An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through
4.14.x. An x86 HVM guest with PCI pass through devices can force the
allocation of all IDT vectors on the system by rebooting itself with MSI or
MSI-X capabilities enabled and entries setup. Such reboots will leak any
vectors used by the MSI(-X) entries that the guest might had enabled, and
hence will lead to vector exhaustion on the system, not allowing further
PCI pass through devices to work properly. HVM guests with PCI pass through
devices can mount a Denial of Service (DoS) attack affecting the pass
through of PCI devices to other guests or the hardware domain. In the
latter case, this would affect the entire host.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=981052&gt;

Notes