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 kvms390vsiegmapnotifier resulting in a crash. This is due to the fact that we add gmap->private == kvm after creation:
static int acquiregmapshadow(struct kvmvcpu *vcpu, struct vsiepage *vsiepage) { [...] gmap = gmapshadow(vcpu->arch.gmap, asce, edat); if (ISERR(gmap)) return PTRERR(gmap); gmap->private = vcpu->kvm;
Let children inherit the private field of the parent.