diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-08-04 23:50:28 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-08-10 15:08:23 -0400 |
| commit | 70c8327c11c6d4080d4a774f531c6a6521592568 (patch) | |
| tree | 0911e4769add9407e27308d71fd6cc4f8c549b15 /arch | |
| parent | c3c28d24d910a746b02f496d190e0e8c6560224b (diff) | |
KVM: x86: Bug the VM if an accelerated x2APIC trap occurs on a "bad" reg
Bug the VM if retrieving the x2APIC MSR/register while processing an
accelerated vAPIC trap VM-Exit fails. In theory it's impossible for the
lookup to fail as hardware has already validated the register, but bugs
happen, and not checking the result of kvm_lapic_msr_read() would result
in consuming the uninitialized "val" if a KVM or hardware bug occurs.
Fixes: 1bd9dfec9fd4 ("KVM: x86: Do not block APIC write for non ICR registers")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220804235028.1766253-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index e2ce3556915e..9dda989a1cf0 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2284,10 +2284,12 @@ void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset) struct kvm_lapic *apic = vcpu->arch.apic; u64 val; - if (apic_x2apic_mode(apic)) - kvm_lapic_msr_read(apic, offset, &val); - else + if (apic_x2apic_mode(apic)) { + if (KVM_BUG_ON(kvm_lapic_msr_read(apic, offset, &val), vcpu->kvm)) + return; + } else { val = kvm_lapic_get_reg(apic, offset); + } /* * ICR is a single 64-bit register when x2APIC is enabled. For legacy |