Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964913AbdCJNT6 (ORCPT ); Fri, 10 Mar 2017 08:19:58 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43497 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933083AbdCJLwu (ORCPT ); Fri, 10 Mar 2017 06:52:50 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Paolo Bonzini" , "Dmitry Vyukov" Date: Fri, 10 Mar 2017 11:46:23 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 367/370] kvm: fix page struct leak in handle_vmon In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1226 Lines: 43 3.16.42-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini 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 [bwh: Backported to 3.16: use skip_emulated_instruction()] Signed-off-by: Ben Hutchings --- --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5954,14 +5954,20 @@ 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: