4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Paolo Bonzini <[email protected]> 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 <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> [bwh: Backported to 3.16: use skip_emulated_instruction()] Signed-off-by: Ben Hutchings <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kvm/vmx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6678,14 +6678,20 @@ static int nested_vmx_check_vmptr(struct } page = nested_get_page(vcpu, vmptr); - if (page == NULL || - *(u32 *)kmap(page) != VMCS12_REVISION) { + if (page == NULL) { nested_vmx_failInvalid(vcpu); + skip_emulated_instruction(vcpu); + return 1; + } + if (*(u32 *)kmap(page) != VMCS12_REVISION) { kunmap(page); + nested_release_page_clean(page); + nested_vmx_failInvalid(vcpu); skip_emulated_instruction(vcpu); return 1; } kunmap(page); + nested_release_page_clean(page); vmx->nested.vmxon_ptr = vmptr; break; case EXIT_REASON_VMCLEAR:
