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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E79A6C2BA83 for ; Fri, 14 Feb 2020 13:13:13 +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 B398F2086A for ; Fri, 14 Feb 2020 13:13:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ii759axH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B398F2086A 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]:38594 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j2amO-0005XL-WF for qemu-devel@archiver.kernel.org; Fri, 14 Feb 2020 08:13:13 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47360) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j2ali-0004jQ-0Q for qemu-devel@nongnu.org; Fri, 14 Feb 2020 08:12:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j2alg-0001mk-Ty for qemu-devel@nongnu.org; Fri, 14 Feb 2020 08:12:29 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:59360 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 1j2alg-0001m2-Py for qemu-devel@nongnu.org; Fri, 14 Feb 2020 08:12:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581685948; 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=76fYOj2p/hlVqL0xNxyP7e1V8V9UC2UUbu4VyTyOZy0=; b=ii759axHfVje6WQzQqf3+fe69o0Rp4LiAebtRM79E3+rDFZW3RYUAlDI4SOLl2BRzCXrBU v0Z8iln/URU0MqGnhNY+q/0rvKsnmcBCAoeIj0XWOzGPE56xdaez+hmCy+F+00H6ZLTnb+ nE1BMfT99Vke2+PwYnUYvH7BZy5R+hs= 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-392-kWEABTSgNuu43zEN1StYeg-1; Fri, 14 Feb 2020 08:12:25 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id ED51D1851FDD; Fri, 14 Feb 2020 13:12:24 +0000 (UTC) Received: from linux.fritz.box (unknown [10.36.118.128]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ECD5C5C13E; Fri, 14 Feb 2020 13:12:23 +0000 (UTC) Date: Fri, 14 Feb 2020 14:12:22 +0100 From: Kevin Wolf To: Hikaru Nishida Subject: Re: [PATCH] block/vvfat: Do not unref qcow on closing backing bdrv Message-ID: <20200214131222.GC5443@linux.fritz.box> References: <20200209175156.85748-1-hikarupsp@gmail.com> MIME-Version: 1.0 In-Reply-To: <20200209175156.85748-1-hikarupsp@gmail.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: kWEABTSgNuu43zEN1StYeg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 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, "open list:vvfat" , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 09.02.2020 um 18:51 hat Hikaru Nishida geschrieben: > Before this commit, BDRVVVFATState.qcow is unrefed in write_target_close > on closing backing bdrv of vvfat. However, qcow bdrv is opend as a child > of vvfat in enable_write_target() so it will be also unrefed on closing > vvfat itself. This causes use-after-free of qcow on freeing vvfat which > has backing bdrv and qcow bdrv as children in this order because > bdrv_close(vvfat) tries to free qcow bdrv after freeing backing bdrv > as QLIST_FOREACH_SAFE() loop keeps next pointer, but BdrvChild of qcow > is already freed in bdrv_close(backing bdrv). >=20 > Signed-off-by: Hikaru Nishida Thanks, applied to the block branch. Kevin