From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F2DBC2D0C2 for ; Tue, 31 Dec 2019 10:52:32 +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 4258A206D9 for ; Tue, 31 Dec 2019 10:52:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AAwNNqXz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4258A206D9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41154 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1imF8Z-0006zD-9o for qemu-devel@archiver.kernel.org; Tue, 31 Dec 2019 05:52:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38717) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1imF7r-0006G4-Uu for qemu-devel@nongnu.org; Tue, 31 Dec 2019 05:51:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1imF7o-0000dP-Tc for qemu-devel@nongnu.org; Tue, 31 Dec 2019 05:51:45 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:51014 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1imF7o-0000an-NO for qemu-devel@nongnu.org; Tue, 31 Dec 2019 05:51:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1577789504; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1UAE0AtIez2HdWdyxJdb6ylgmz6+ahVBb7sXcCocAQk=; b=AAwNNqXzj7ZpYApJXJPFF0yQ3rUCEhghRbgkKCjhsUm42s0gsD6UmJCUipp2o/OCctsG7X JBFk86vGOI2CZdc6RKqDEyTSwhGuN8dCy4BBeNppgJg7iFqSnCgpborM1mpMZvj1fNwOSb wpS/roR01KBLd0aQ7eTWH7NEJbUyYQk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-113-Nx0XsU3JPFacJrQSRl54yg-1; Tue, 31 Dec 2019 05:51:40 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 476311005502; Tue, 31 Dec 2019 10:51:39 +0000 (UTC) Received: from Igors-MacBook-Pro (ovpn-204-105.brq.redhat.com [10.40.204.105]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B7B65C1C3; Tue, 31 Dec 2019 10:51:38 +0000 (UTC) Date: Tue, 31 Dec 2019 11:51:35 +0100 From: Igor Mammedov To: Eryu Guan Subject: Re: [BUG qemu 4.0] segfault when unplugging virtio-blk-pci device Message-ID: <20191231115136.7b967604@Igors-MacBook-Pro> In-Reply-To: <20191231103434.GA41863@e18g06458.et15sqa> References: <20191231103434.GA41863@e18g06458.et15sqa> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: Nx0XsU3JPFacJrQSRl54yg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 31 Dec 2019 18:34:34 +0800 Eryu Guan wrote: > Hi, >=20 > I'm using qemu 4.0 and hit segfault when tearing down kata sandbox, I > think it's because io completion hits use-after-free when device is > already gone. Is this a known bug that has been fixed? (I went through > the git log but didn't find anything obvious). >=20 > gdb backtrace is: >=20 > Core was generated by `/usr/local/libexec/qemu-kvm -name sandbox-5b8df8c6= c6901c3c0a9b02879be10fe8d69d6'. > Program terminated with signal 11, Segmentation fault. > #0 object_get_class (obj=3Dobj@entry=3D0x0) at /usr/src/debug/qemu-4.0/qo= m/object.c:903 > 903 return obj->class; > (gdb) bt > #0 object_get_class (obj=3Dobj@entry=3D0x0) at /usr/src/debug/qemu-4.0/q= om/object.c:903 > #1 =C2=A00x0000558a2c009e9b in virtio_notify_vector (vdev=3D0x558a2e7751d= 0, > =C2=A0 =C2=A0 vector=3D) at /usr/src/debug/qemu-4.0/hw/vir= tio/virtio.c:1118 > #2 =C2=A00x0000558a2bfdcb1e in virtio_blk_discard_write_zeroes_complete ( > =C2=A0 =C2=A0 opaque=3D0x558a2f2fd420, ret=3D0) > =C2=A0 =C2=A0 at /usr/src/debug/qemu-4.0/hw/block/virtio-blk.c:186 > #3 =C2=A00x0000558a2c261c7e in blk_aio_complete (acb=3D0x558a2eed7420) > =C2=A0 =C2=A0 at /usr/src/debug/qemu-4.0/block/block-backend.c:1305 > #4 =C2=A00x0000558a2c3031db in coroutine_trampoline (i0=3D= , > =C2=A0 =C2=A0 i1=3D) at /usr/src/debug/qemu-4.0/util/corou= tine-ucontext.c:116 > #5 =C2=A00x00007f45b2f8b080 in ?? () from /lib64/libc.so.6 > #6 =C2=A00x00007fff9ed75780 in ?? () > #7 =C2=A00x0000000000000000 in ?? () >=20 > It seems like qemu was completing a discard/write_zero request, but > parent BusState was already freed & set to NULL. >=20 > Do we need to drain all pending request before unrealizing virtio-blk > device? Like the following patch proposed? >=20 > https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg02945.html >=20 > If more info is needed, please let me know. may be this will help: https://patchwork.kernel.org/patch/11213047/ >=20 > Thanks, > Eryu >=20