From: Thomas Huth <thuth@xxxxxxxxxx> If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this clearly indicates that something went wrong in the KVM userspace application. The x86 variant of KVM already contains a check for bad bits, so let's do the same on s390x now, too. Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx> Link: https://lore.kernel.org/lkml/20190904085200.29021-2-thuth@xxxxxxxxxx/ Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> --- arch/s390/include/uapi/asm/kvm.h | 6 ++++++ arch/s390/kvm/kvm-s390.c | 4 ++++ 2 files changed, 10 insertions(+) diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 47104e5b47fd..436ec7636927 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -231,6 +231,12 @@ struct kvm_guest_debug_arch { #define KVM_SYNC_GSCB (1UL << 9) #define KVM_SYNC_BPBC (1UL << 10) #define KVM_SYNC_ETOKEN (1UL << 11) + +#define KVM_SYNC_S390_VALID_FIELDS \ + (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \ + KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \ + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN) + /* length and alignment of the sdnx as a power of two */ #define SDNXC 8 #define SDNXL (1UL << SDNXC) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index d41c091546b7..a3d4527ac23b 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -4008,6 +4008,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) if (kvm_run->immediate_exit) return -EINTR; + if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS || + kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS) + return -EINVAL; + vcpu_load(vcpu); if (guestdbg_exit_pending(vcpu)) { -- 2.20.1
