KVM: vmx: use local variable for current_vmptr when emulating VMPTRST (0a06d425) · Commits · 戴 / test

Do not expose the address of vmx->nested.current_vmptr to kvm_write_guest_virt_system() as the resulting __copy_to_user() call will trigger a WARN when CONFIG_HARDENED_USERCOPY is enabled. Opportunistically clean up variable names in handle_vmptrst() to improve readability, e.g. vmcs_gva is misleading as the memory operand of VMPTRST is plain memory, not a VMCS. Signed-off-by:

Sean Christopherson <sean.j.christopherson@intel.com> Tested-by:

Peter Shier <pshier@google.com> Reviewed-by:

Peter Shier <pshier@google.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

+7 −8

Original line number	Diff line number	Diff line
		@@ -8480,21 +8480,20 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
		/* Emulate the VMPTRST instruction */
		static int handle_vmptrst(struct kvm_vcpu *vcpu)
		{
		unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
		u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
		gva_t vmcs_gva;
		unsigned long exit_qual = vmcs_readl(EXIT_QUALIFICATION);
		u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
		gpa_t current_vmptr = to_vmx(vcpu)->nested.current_vmptr;
		struct x86_exception e;
		gva_t gva;

		if (!nested_vmx_check_permission(vcpu))
		return 1;

		if (get_vmx_mem_address(vcpu, exit_qualification,
		vmx_instruction_info, true, &vmcs_gva))
		if (get_vmx_mem_address(vcpu, exit_qual, instr_info, true, &gva))
		return 1;
		/* _system ok, nested_vmx_check_permission has verified cpl=0 /
		if (kvm_write_guest_virt_system(vcpu, vmcs_gva,
		(void *)&to_vmx(vcpu)->nested.current_vmptr,
		sizeof(u64), &e)) {
		if (kvm_write_guest_virt_system(vcpu, gva, (void *)&current_vmptr,
		sizeof(gpa_t), &e)) {
		kvm_inject_page_fault(vcpu, &e);
		return 1;
		}

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