Use an unsigned long for 'exit_qual' in nested_vmx_reflect_vmexit(), the
EXIT_QUALIFICATION field is naturally sized, not a 32-bit field.
The bug is most easily observed by doing VMXON (or any VMX instruction)
in L2 with a negative displacement, in which case dropping the upper
bits on nested VM-Exit results in L1 calculating the wrong virtual
address for the memory operand, e.g. "vmxon -0x8(%rbp)" yields:
Unhandled cpu exception 14 #PF at ip 0000000000400553
rbp=0000000000537000 cr2=0000000100536ff8
Fixes: fbdd50250396d ("KVM: nVMX: Move VM-Fail check out of nested_vmx_exit_reflected()")
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
Sadly (for me), I can't blame a mishandled merge on this one. Even more
embarassing is that this is actually the second instance where I botched
the size for exit_qual, you'd think I'd have double-checked everything
after the first one...
arch/x86/kvm/vmx/nested.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f228339cd0a0..3f32f81f5c59 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5814,7 +5814,8 @@ bool nested_vmx_reflect_vmexit(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 exit_reason = vmx->exit_reason;
- u32 exit_intr_info, exit_qual;
+ unsigned long exit_qual;
+ u32 exit_intr_info;
WARN_ON_ONCE(vmx->nested.nested_run_pending);
--
2.26.0
