From patchwork Fri Jul 4 06:52:38 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 4478181 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0798F9F36A for ; Fri, 4 Jul 2014 06:53:22 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 393A82040F for ; Fri, 4 Jul 2014 06:53:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57E0D203E5 for ; Fri, 4 Jul 2014 06:53:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751844AbaGDGxD (ORCPT ); Fri, 4 Jul 2014 02:53:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:54022 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412AbaGDGxA (ORCPT ); Fri, 4 Jul 2014 02:53:00 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 03 Jul 2014 23:47:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,599,1400050800"; d="scan'208";a="568273922" Received: from wanpengl-mobl.ccr.corp.intel.com (HELO localhost) ([10.238.130.40]) by orsmga002.jf.intel.com with ESMTP; 03 Jul 2014 23:52:57 -0700 From: Wanpeng Li To: Paolo Bonzini , Jan Kiszka Cc: Marcelo Tosatti , Bandan Das , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH] KVM: nVMX: Fix vmptrld fail and vmwrite error when L1 goes down w/ enable_shadow_vmcs Date: Fri, 4 Jul 2014 14:52:38 +0800 Message-Id: <1404456758-33691-1-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.7.9.5 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This bug can be trigger by L1 goes down directly w/ enable_shadow_vmcs. [ 6413.158950] kvm: vmptrld (null)/780000000000 failed [ 6413.158954] vmwrite error: reg 401e value 4 (err 1) [ 6413.158957] CPU: 0 PID: 4840 Comm: qemu-system-x86 Tainted: G OE 3.16.0kvm+ #2 [ 6413.158958] Hardware name: Dell Inc. OptiPlex 9020/0DNKMN, BIOS A05 12/05/2013 [ 6413.158959] 0000000000000003 ffff880210c9fb58 ffffffff81741de9 ffff8800d7433f80 [ 6413.158960] ffff880210c9fb68 ffffffffa059fa08 ffff880210c9fb78 ffffffffa05938bf [ 6413.158962] ffff880210c9fba8 ffffffffa059a97f ffff8800d7433f80 0000000000000003 [ 6413.158963] Call Trace: [ 6413.158968] [] dump_stack+0x45/0x56 [ 6413.158972] [] vmwrite_error+0x2c/0x2e [kvm_intel] [ 6413.158974] [] vmcs_writel+0x1f/0x30 [kvm_intel] [ 6413.158976] [] free_nested.part.73+0x5f/0x170 [kvm_intel] [ 6413.158978] [] vmx_free_vcpu+0x33/0x70 [kvm_intel] [ 6413.158991] [] kvm_arch_vcpu_free+0x44/0x50 [kvm] [ 6413.158998] [] kvm_arch_destroy_vm+0xf2/0x1f0 [kvm] Commit 26a865 (KVM: VMX: fix use after free of vmx->loaded_vmcs) fix the use after free bug by move free_loaded_vmcs() before free_nested(), however, this lead to free loaded_vmcs->vmcs premature and vmptrld load a NULL pointer during sync shadow vmcs to vmcs12. In addition, vmwrite which used to disable shadow vmcs and reset VMCS_LINK_POINTER failed since there is no valid current-VMCS. This patch fix it by skipping kfree vmcs02_list item for current-vmcs in nested_free_all_saved_vmcss() and kfree it after free_loaded_vmcs(). This can also avoid use after free bug. Signed-off-by: Wanpeng Li --- arch/x86/kvm/vmx.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 021d84a..6e427ac 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5762,10 +5762,11 @@ static void nested_free_all_saved_vmcss(struct vcpu_vmx *vmx) { struct vmcs02_list *item, *n; list_for_each_entry_safe(item, n, &vmx->nested.vmcs02_pool, list) { - if (vmx->loaded_vmcs != &item->vmcs02) + if (vmx->loaded_vmcs != &item->vmcs02) { free_loaded_vmcs(&item->vmcs02); - list_del(&item->list); - kfree(item); + list_del(&item->list); + kfree(item); + } } vmx->nested.vmcs02_num = 0; @@ -7526,10 +7527,16 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) static void vmx_free_vcpu(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); + struct vmcs02_list *item; free_vpid(vmx); - free_loaded_vmcs(vmx->loaded_vmcs); free_nested(vmx); + free_loaded_vmcs(vmx->loaded_vmcs); + if (vmx->nested.vmxon) + list_for_each_entry(item, &vmx->nested.vmcs02_pool, list) { + list_del(&item->list); + kfree(item); + } kfree(vmx->guest_msrs); kvm_vcpu_uninit(vcpu); kmem_cache_free(kvm_vcpu_cache, vmx);