From patchwork Tue May 12 13:39:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pan Nengyuan X-Patchwork-Id: 11542213 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF9EF14C0 for ; Tue, 12 May 2020 07:16:42 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7953E20675 for ; Tue, 12 May 2020 07:16:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7953E20675 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:32992 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYP9d-0006sw-Kl for patchwork-qemu-devel@patchwork.kernel.org; Tue, 12 May 2020 03:16:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54880) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYP8u-0006PH-VB for qemu-devel@nongnu.org; Tue, 12 May 2020 03:15:56 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:3763 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYP8r-0001rj-Mw for qemu-devel@nongnu.org; Tue, 12 May 2020 03:15:56 -0400 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 3561BED1A72B48253AD3; Tue, 12 May 2020 15:15:43 +0800 (CST) Received: from opensource.huawei.com (10.175.100.98) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.487.0; Tue, 12 May 2020 15:15:35 +0800 From: Pan Nengyuan To: , , , Subject: [PATCH] i386/kvm: fix a use-after-free when vcpu plug/unplug Date: Tue, 12 May 2020 09:39:33 -0400 Message-ID: <20200512133933.8696-1-pannengyuan@huawei.com> X-Mailer: git-send-email 2.18.2 MIME-Version: 1.0 X-Originating-IP: [10.175.100.98] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.191; envelope-from=pannengyuan@huawei.com; helo=huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/12 03:15:43 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DATE_IN_FUTURE_06_12=1.947, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: euler.robot@huawei.com, Pan Nengyuan , qemu-devel@nongnu.org, kvm@vger.kernel.org, zhang.zhanghailiang@huawei.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" When we hotplug vcpus, cpu_update_state is added to vm_change_state_head in kvm_arch_init_vcpu(). But it forgot to delete in kvm_arch_destroy_vcpu() after unplug. Then it will cause a use-after-free access. This patch delete it in kvm_arch_destroy_vcpu() to fix that. Reproducer: virsh setvcpus vm1 4 --live virsh setvcpus vm1 2 --live virsh suspend vm1 virsh resume vm1 The UAF stack: ==qemu-system-x86_64==28233==ERROR: AddressSanitizer: heap-use-after-free on address 0x62e00002e798 at pc 0x5573c6917d9e bp 0x7fff07139e50 sp 0x7fff07139e40 WRITE of size 1 at 0x62e00002e798 thread T0 #0 0x5573c6917d9d in cpu_update_state /mnt/sdb/qemu/target/i386/kvm.c:742 #1 0x5573c699121a in vm_state_notify /mnt/sdb/qemu/vl.c:1290 #2 0x5573c636287e in vm_prepare_start /mnt/sdb/qemu/cpus.c:2144 #3 0x5573c6362927 in vm_start /mnt/sdb/qemu/cpus.c:2150 #4 0x5573c71e8304 in qmp_cont /mnt/sdb/qemu/monitor/qmp-cmds.c:173 #5 0x5573c727cb1e in qmp_marshal_cont qapi/qapi-commands-misc.c:835 #6 0x5573c7694c7a in do_qmp_dispatch /mnt/sdb/qemu/qapi/qmp-dispatch.c:132 #7 0x5573c7694c7a in qmp_dispatch /mnt/sdb/qemu/qapi/qmp-dispatch.c:175 #8 0x5573c71d9110 in monitor_qmp_dispatch /mnt/sdb/qemu/monitor/qmp.c:145 #9 0x5573c71dad4f in monitor_qmp_bh_dispatcher /mnt/sdb/qemu/monitor/qmp.c:234 Reported-by: Euler Robot Signed-off-by: Pan Nengyuan Reviewed-by: Philippe Mathieu-Daudé --- target/i386/cpu.h | 1 + target/i386/kvm.c | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index e818fc712a..afbd11b7a3 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1631,6 +1631,7 @@ struct X86CPU { CPUNegativeOffsetState neg; CPUX86State env; + VMChangeStateEntry *vmsentry; uint64_t ucode_rev; diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 4901c6dd74..ff2848357e 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -1770,7 +1770,7 @@ int kvm_arch_init_vcpu(CPUState *cs) } } - qemu_add_vm_change_state_handler(cpu_update_state, env); + cpu->vmsentry = qemu_add_vm_change_state_handler(cpu_update_state, env); c = cpuid_find_entry(&cpuid_data.cpuid, 1, 0); if (c) { @@ -1883,6 +1883,9 @@ int kvm_arch_destroy_vcpu(CPUState *cs) env->nested_state = NULL; } + qemu_del_vm_change_state_handler(cpu->vmsentry); + cpu->vmsentry = NULL; + return 0; }