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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 7366DC34026 for ; Tue, 18 Feb 2020 14:09:09 +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 3600A20722 for ; Tue, 18 Feb 2020 14:09:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="L73UJ6Ze" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3600A20722 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]:35720 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j43Yi-0000OB-EK for qemu-devel@archiver.kernel.org; Tue, 18 Feb 2020 09:09:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52730) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j43Xe-0006pK-Pw for qemu-devel@nongnu.org; Tue, 18 Feb 2020 09:08:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j43Xd-0001OA-Gh for qemu-devel@nongnu.org; Tue, 18 Feb 2020 09:08:02 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:49489 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 1j43Xd-0001Nz-DI for qemu-devel@nongnu.org; Tue, 18 Feb 2020 09:08:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582034881; 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=BoHRYn0ddHGPZPzr3V33ur7osgG+95vDlfAmZvJ+gaU=; b=L73UJ6Ze6/nrLJleL3CC42BVubpEoMc/nMVtHpLgDu2lNCKNOjjKT5MJu98myXMgwvB9Dt g+YbW0rCuVC6IBK1u+g3AmIdtj0k+U3GYmnIhVcK88GRKs/3OJebhdXllLUqdtpZ6veW0s +4Drq2zTKnA/e/l4pzLj55V268ChMzM= 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-144-hWnM10f4MoKHb5DMA2s0Fg-1; Tue, 18 Feb 2020 09:07:58 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 44008801A2B; Tue, 18 Feb 2020 14:07:57 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-117-181.ams2.redhat.com [10.36.117.181]) by smtp.corp.redhat.com (Postfix) with ESMTP id 433D88B740; Tue, 18 Feb 2020 14:07:56 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PULL 04/36] block/vvfat: Do not unref qcow on closing backing bdrv Date: Tue, 18 Feb 2020 15:06:50 +0100 Message-Id: <20200218140722.23876-5-kwolf@redhat.com> In-Reply-To: <20200218140722.23876-1-kwolf@redhat.com> References: <20200218140722.23876-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: hWnM10f4MoKHb5DMA2s0Fg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable 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: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Hikaru Nishida 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). Signed-off-by: Hikaru Nishida Message-Id: <20200209175156.85748-1-hikarupsp@gmail.com> Signed-off-by: Kevin Wolf --- block/vvfat.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/block/vvfat.c b/block/vvfat.c index 019b8f1341..ab800c4887 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -3124,17 +3124,10 @@ write_target_commit(BlockDriverState *bs, uint64_t = offset, uint64_t bytes, return ret; } =20 -static void write_target_close(BlockDriverState *bs) { - BDRVVVFATState* s =3D *((BDRVVVFATState**) bs->opaque); - bdrv_unref_child(s->bs, s->qcow); - g_free(s->qcow_filename); -} - static BlockDriver vvfat_write_target =3D { .format_name =3D "vvfat_write_target", .instance_size =3D sizeof(void*), .bdrv_co_pwritev =3D write_target_commit, - .bdrv_close =3D write_target_close, }; =20 static void vvfat_qcow_options(int *child_flags, QDict *child_options, --=20 2.20.1