From 0a06d4256674c4e041945b52044941995fee237d Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 19 Jul 2018 10:31:00 -0700 Subject: [PATCH] KVM: vmx: use local variable for current_vmptr when emulating VMPTRST 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 Tested-by: Peter Shier Reviewed-by: Peter Shier Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e30da9a2430c..548bef5359e6 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -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 *)¤t_vmptr, + sizeof(gpa_t), &e)) { kvm_inject_page_fault(vcpu, &e); return 1; }