CVE-2022-50227

In the Linux kernel, the following vulnerability has been resolved:

KVM: x86/xen: Initialize Xen timer only once

Add a check for existing xen timers before initializing a new one.

Currently kvm_xen_init_timer() is called on every

KVM_XEN_VCPU_ATTR_TYPE_TIMER, which is causing the following ODEBUG

crash when vcpu->arch.xen.timer is already set.

ODEBUG: init active (active state 0)

object type: hrtimer hint: xen_timer_callbac0

RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502

Call Trace:

__debug_object_init

debug_hrtimer_init

debug_init

hrtimer_init

kvm_xen_init_timer

kvm_xen_vcpu_set_attr

kvm_arch_vcpu_ioctl

kvm_vcpu_ioctl

vfs_ioctl