Commit cf5029d5 authored by Aaron Lewis's avatar Aaron Lewis Committed by Paolo Bonzini
Browse files

KVM: x86: Protect the unused bits in MSR exiting flags 



The flags for KVM_CAP_X86_USER_SPACE_MSR and KVM_X86_SET_MSR_FILTER
have no protection for their unused bits.  Without protection, future
development for these features will be difficult.  Add the protection
needed to make it possible to extend these features in the future.

Signed-off-by: default avatarAaron Lewis <aaronlewis@google.com>
Message-Id: <20220714161314.1715227-1-aaronlewis@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent dc951e22

arch/x86/kvm/x86.c

+8 −0
Original line number Diff line number Diff line
@@ -6029,6 +6029,11 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, 
		r = 0;

		break;

	case KVM_CAP_X86_USER_SPACE_MSR:

		r = -EINVAL;

		if (cap->args[0] & ~(KVM_MSR_EXIT_REASON_INVAL |

				     KVM_MSR_EXIT_REASON_UNKNOWN |

				     KVM_MSR_EXIT_REASON_FILTER))

			break;

		kvm->arch.user_space_msr_mask = cap->args[0];

		r = 0;

		break;
@@ -6183,6 +6188,9 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) 
	if (copy_from_user(&filter, user_msr_filter, sizeof(filter)))

		return -EFAULT;



	if (filter.flags & ~KVM_MSR_FILTER_DEFAULT_DENY)

		return -EINVAL;



	for (i = 0; i < ARRAY_SIZE(filter.ranges); i++)

		empty &= !filter.ranges[i].nmsrs;