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=-7.0 required=3.0 tests=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 63B06C4740A for ; Tue, 10 Sep 2019 13:52:41 +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 386F42082C for ; Tue, 10 Sep 2019 13:52:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 386F42082C 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]:40010 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7gZT-0000jv-Fj for qemu-devel@archiver.kernel.org; Tue, 10 Sep 2019 09:52:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43600) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7gTw-0005UN-Tb for qemu-devel@nongnu.org; Tue, 10 Sep 2019 09:46:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i7gTv-0003Gw-EF for qemu-devel@nongnu.org; Tue, 10 Sep 2019 09:46:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44192) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i7gTt-0003Fs-6T; Tue, 10 Sep 2019 09:46:53 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 730AC58; Tue, 10 Sep 2019 13:46:52 +0000 (UTC) Received: from dritchie.redhat.com (unknown [10.33.36.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 803FE60BE2; Tue, 10 Sep 2019 13:46:39 +0000 (UTC) From: Sergio Lopez To: qemu-block@nongnu.org Date: Tue, 10 Sep 2019 15:36:13 +0200 Message-Id: <20190910133611.149421-1-slp@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 10 Sep 2019 13:46:52 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2] blockjob: update nodes head while removing all bdrv 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, jsnow@redhat.com, qemu-devel@nongnu.org, Sergio Lopez , mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" block_job_remove_all_bdrv() iterates through job->nodes, calling bdrv_root_unref_child() for each entry. The call to the latter may reach child_job_[can_]set_aio_ctx(), which will also attempt to traverse job->nodes, potentially finding entries that where freed on previous iterations. To avoid this situation, update job->nodes head on each iteration to ensure that already freed entries are no longer linked to the list. RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=3D1746631 Signed-off-by: Sergio Lopez --- Changelog v2: - Avoid leaking job->nodes (thanks Max Reitz) --- blockjob.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- diff --git a/blockjob.c b/blockjob.c index 6e32d1a0c0..ffda6dd1e4 100644 --- a/blockjob.c +++ b/blockjob.c @@ -187,13 +187,21 @@ static const BdrvChildRole child_job =3D { =20 void block_job_remove_all_bdrv(BlockJob *job) { - GSList *l; + GSList *l, *orig_nodes; + + orig_nodes =3D job->nodes; for (l =3D job->nodes; l; l =3D l->next) { BdrvChild *c =3D l->data; bdrv_op_unblock_all(c->bs, job->blocker); bdrv_root_unref_child(c); + /* + * The call above may reach child_job_[can_]set_aio_ctx(), which= will + * also traverse job->nodes, so update the head here to make sur= e it + * doesn't attempt to process an already freed BdrvChild. + */ + job->nodes =3D l->next; } - g_slist_free(job->nodes); + g_slist_free(orig_nodes); job->nodes =3D NULL; } =20 --=20 2.21.0