CVE-2026-62432 evtchn: Race between FIFO expand and reset

The EVTCHNOPexpandarray hypercall checks for whether FIFO event channels are enabled, but without holding the correct lock. It can race with EVTCHNOPreset, resulting in dereferencing a NULL pointer...

UBUNTU-CVE-2020-29571

An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered read...