From b04940e26f100c7d19fc0b5cab0210d4d924b002 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 24 Jan 2017 11:56:21 +0100 Subject: kvm: fix page struct leak in handle_vmon commit 06ce521af9558814b8606c0476c54497cf83a653 upstream. handle_vmon gets a reference on VMXON region page, but does not release it. Release the reference. Found by syzkaller; based on a patch by Dmitry. Reported-by: Dmitry Vyukov Signed-off-by: Paolo Bonzini Cc: "Charles (Chas) Williams" Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9764463ce833..cce7d2e3be15 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7086,13 +7086,18 @@ static int nested_vmx_check_vmptr(struct kvm_vcpu *vcpu, int exit_reason, } page = nested_get_page(vcpu, vmptr); - if (page == NULL || - *(u32 *)kmap(page) != VMCS12_REVISION) { + if (page == NULL) { nested_vmx_failInvalid(vcpu); + return kvm_skip_emulated_instruction(vcpu); + } + if (*(u32 *)kmap(page) != VMCS12_REVISION) { kunmap(page); + nested_release_page_clean(page); + nested_vmx_failInvalid(vcpu); return kvm_skip_emulated_instruction(vcpu); } kunmap(page); + nested_release_page_clean(page); vmx->nested.vmxon_ptr = vmptr; break; case EXIT_REASON_VMCLEAR: -- cgit v1.2.3