From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934325AbdK2R0U (ORCPT ); Wed, 29 Nov 2017 12:26:20 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:24542 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934420AbdK2RX6 (ORCPT ); Wed, 29 Nov 2017 12:23:58 -0500 From: alexander.levin@verizon.com Cc: Wanpeng Li , Paolo Bonzini , =?utf-8?B?UmFkaW0gS3LEjW3DocWZ?= , Dmitry Vyukov , David Hildenbrand , alexander.levin@verizon.com X-Host: pioneer.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 3.18 08/16] KVM: nVMX: reset nested_run_pending if the vCPU is going to be reset Thread-Topic: [PATCH AUTOSEL for 3.18 08/16] KVM: nVMX: reset nested_run_pending if the vCPU is going to be reset Thread-Index: AQHTaTaduOaQ0//88USQNNTZOptQLw== Date: Wed, 29 Nov 2017 17:22:20 +0000 Message-ID: <20171129172213.29007-8-alexander.levin@verizon.com> References: <20171129172213.29007-1-alexander.levin@verizon.com> In-Reply-To: <20171129172213.29007-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="utf-8" Content-ID: <328FFD41BC9DAA448706B80C39BB84BD@vzwcorp.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id vATHQN8t032304 From: Wanpeng Li [ Upstream commit 2f707d97982286b307ef2a9b034e19aabc1abb56 ] Reported by syzkaller: WARNING: CPU: 1 PID: 27742 at arch/x86/kvm/vmx.c:11029 nested_vmx_vmexit+0x5c35/0x74d0 arch/x86/kvm/vmx.c:11029 CPU: 1 PID: 27742 Comm: a.out Not tainted 4.10.0+ #229 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 panic+0x1fb/0x412 kernel/panic.c:179 __warn+0x1c4/0x1e0 kernel/panic.c:540 warn_slowpath_null+0x2c/0x40 kernel/panic.c:583 nested_vmx_vmexit+0x5c35/0x74d0 arch/x86/kvm/vmx.c:11029 vmx_leave_nested arch/x86/kvm/vmx.c:11136 [inline] vmx_set_msr+0x1565/0x1910 arch/x86/kvm/vmx.c:3324 kvm_set_msr+0xd4/0x170 arch/x86/kvm/x86.c:1099 do_set_msr+0x11e/0x190 arch/x86/kvm/x86.c:1128 __msr_io arch/x86/kvm/x86.c:2577 [inline] msr_io+0x24b/0x450 arch/x86/kvm/x86.c:2614 kvm_arch_vcpu_ioctl+0x35b/0x46a0 arch/x86/kvm/x86.c:3497 kvm_vcpu_ioctl+0x232/0x1120 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2721 vfs_ioctl fs/ioctl.c:43 [inline] do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 SYSC_ioctl fs/ioctl.c:698 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 entry_SYSCALL_64_fastpath+0x1f/0xc2 The syzkaller folks reported a nested_run_pending warning during userspace clear VMX capability which is exposed to L1 before. The warning gets thrown while doing (*(uint32_t*)0x20aecfe8 = (uint32_t)0x1); (*(uint32_t*)0x20aecfec = (uint32_t)0x0); (*(uint32_t*)0x20aecff0 = (uint32_t)0x3a); (*(uint32_t*)0x20aecff4 = (uint32_t)0x0); (*(uint64_t*)0x20aecff8 = (uint64_t)0x0); r[29] = syscall(__NR_ioctl, r[4], 0x4008ae89ul, 0x20aecfe8ul, 0, 0, 0, 0, 0, 0); i.e. KVM_SET_MSR ioctl with struct kvm_msrs { .nmsrs = 1, .pad = 0, .entries = { {.index = MSR_IA32_FEATURE_CONTROL, .reserved = 0, .data = 0} } } The VMLANCH/VMRESUME emulation should be stopped since the CPU is going to reset here. This patch resets the nested_run_pending since the CPU is going to be reset hence there should be nothing pending. Reported-by: Dmitry Vyukov Suggested-by: Radim Krčmář Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Dmitry Vyukov Cc: David Hildenbrand Signed-off-by: Wanpeng Li Reviewed-by: David Hildenbrand Reviewed-by: Jim Mattson Signed-off-by: Radim Krčmář Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index a9ca10baf936..1990f4c97a62 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -9082,8 +9082,10 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, */ static void vmx_leave_nested(struct kvm_vcpu *vcpu) { - if (is_guest_mode(vcpu)) + if (is_guest_mode(vcpu)) { + to_vmx(vcpu)->nested.nested_run_pending = 0; nested_vmx_vmexit(vcpu, -1, 0, 0); + } free_nested(to_vmx(vcpu)); } -- 2.11.0