In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: vsie: fix race during shadow creation
Right now it is possible to see gmap->private being zero in kvm_s390_vsie_gmap_notifier resulting in a crash. This is due to the fact that we add gmap->private == kvm after creation:
static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { [...] gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); if (IS_ERR(gmap)) return PTR_ERR(gmap); gmap->private = vcpu->kvm;
Let children inherit the private field of the parent.
Exploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:NI:NA:H4.7/CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H