From nobody Fri Dec 19 18:53:20 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1582034954145495.2860189735603; Tue, 18 Feb 2020 06:09:14 -0800 (PST) Received: from localhost ([::1]:35720 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j43Yl-0000OB-UC for importer@patchew.org; Tue, 18 Feb 2020 09:09:11 -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 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) 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= 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-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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" 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