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| author | Sean Christopherson <seanjc@google.com> | 2021-12-07 22:09:25 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-02-10 13:50:35 -0500 |
| commit | 40421f38f63764cd41b01c17e2a1fbbe08a1515a (patch) | |
| tree | f3e726699c8a335d1a4d4702169c2bb70d7fc528 | |
| parent | 9c52f6b3d8c09df75b72dab9a0e6eb2b70435ae1 (diff) | |
| download | linux-stable-40421f38f63764cd41b01c17e2a1fbbe08a1515a.tar.gz linux-stable-40421f38f63764cd41b01c17e2a1fbbe08a1515a.tar.bz2 linux-stable-40421f38f63764cd41b01c17e2a1fbbe08a1515a.zip | |
KVM: x86: Reject fixeds-size Hyper-V hypercalls with non-zero "var_cnt"
Reject Hyper-V hypercalls if the guest specifies a non-zero variable size
header (var_cnt in KVM) for a hypercall that has a fixed header size.
Per the TLFS:
It is illegal to specify a non-zero variable header size for a
hypercall that is not explicitly documented as accepting variable sized
input headers. In such a case the hypercall will result in a return
code of HV_STATUS_INVALID_HYPERCALL_INPUT.
Note, at least some of the various DEBUG commands likely aren't allowed
to use variable size headers, but the TLFS documentation doesn't clearly
state what is/isn't allowed. Omit them for now to avoid unnecessary
breakage.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211207220926.718794-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index e46f267585f4..acabe9d898cf 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -2253,14 +2253,14 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) switch (hc.code) { case HVCALL_NOTIFY_LONG_SPIN_WAIT: - if (unlikely(hc.rep)) { + if (unlikely(hc.rep || hc.var_cnt)) { ret = HV_STATUS_INVALID_HYPERCALL_INPUT; break; } kvm_vcpu_on_spin(vcpu, true); break; case HVCALL_SIGNAL_EVENT: - if (unlikely(hc.rep)) { + if (unlikely(hc.rep || hc.var_cnt)) { ret = HV_STATUS_INVALID_HYPERCALL_INPUT; break; } @@ -2270,7 +2270,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) fallthrough; /* maybe userspace knows this conn_id */ case HVCALL_POST_MESSAGE: /* don't bother userspace if it has no way to handle it */ - if (unlikely(hc.rep || !to_hv_synic(vcpu)->active)) { + if (unlikely(hc.rep || hc.var_cnt || !to_hv_synic(vcpu)->active)) { ret = HV_STATUS_INVALID_HYPERCALL_INPUT; break; } @@ -2283,14 +2283,14 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) kvm_hv_hypercall_complete_userspace; return 0; case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST: - if (unlikely(!hc.rep_cnt || hc.rep_idx)) { + if (unlikely(!hc.rep_cnt || hc.rep_idx || hc.var_cnt)) { ret = HV_STATUS_INVALID_HYPERCALL_INPUT; break; } ret = kvm_hv_flush_tlb(vcpu, &hc, false); break; case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE: - if (unlikely(hc.rep)) { + if (unlikely(hc.rep || hc.var_cnt)) { ret = HV_STATUS_INVALID_HYPERCALL_INPUT; break; } @@ -2311,7 +2311,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) ret = kvm_hv_flush_tlb(vcpu, &hc, true); break; case HVCALL_SEND_IPI: - if (unlikely(hc.rep)) { + if (unlikely(hc.rep || hc.var_cnt)) { ret = HV_STATUS_INVALID_HYPERCALL_INPUT; break; } |