From nobody Fri Oct 24 21:50:32 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520262430303993.3707901674403; Mon, 5 Mar 2018 07:07:10 -0800 (PST) Received: from localhost ([::1]:49919 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1esrhl-0003q5-AS for importer@patchew.org; Mon, 05 Mar 2018 10:07:09 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35854) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1esrgT-00032Q-Ti for qemu-devel@nongnu.org; Mon, 05 Mar 2018 10:05:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1esrgS-0003xJ-Po for qemu-devel@nongnu.org; Mon, 05 Mar 2018 10:05:49 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:54238 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1esrgN-0003tU-Ag; Mon, 05 Mar 2018 10:05:43 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1C3BD81B0AF9; Mon, 5 Mar 2018 15:05:38 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-248.ams2.redhat.com [10.36.116.248]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2260721411BD; Mon, 5 Mar 2018 15:05:32 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 5 Mar 2018 16:05:29 +0100 Message-Id: <20180305150529.11203-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 05 Mar 2018 15:05:38 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 05 Mar 2018 15:05:38 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH] block: Fix NULL dereference on empty drive error X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" blk_error_action() sends a BLOCK_IO_ERROR QMP event which includes the node name of its root node. If the BlockBackend represents an empty drive, there is no root node, so we should not try to access its node name. Make the field optional in the event and include it only when the BlockBackend isn't empty. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- Stefan, this is needed for your patch that reverts the workaround in the IDE flush code. Without it, make check seems to succeed, but if you look closer, qemu actually segfaults. qapi/block-core.json | 6 ++++-- block/block-backend.c | 5 +++-- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/qapi/block-core.json b/qapi/block-core.json index 5c5921bfb7..00475f08d4 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -3676,7 +3676,8 @@ # # @node-name: node name. Note that errors may be reported for the root node # that is directly attached to a guest device rather than for = the -# node where the error occurred. (Since: 2.8) +# node where the error occurred. The node name is not present = if +# the drive is empty. (Since: 2.8) # # @operation: I/O operation # @@ -3707,7 +3708,8 @@ # ## { 'event': 'BLOCK_IO_ERROR', - 'data': { 'device': 'str', 'node-name': 'str', 'operation': 'IoOperation= Type', + 'data': { 'device': 'str', '*node-name': 'str', + 'operation': 'IoOperationType', 'action': 'BlockErrorAction', '*nospace': 'bool', 'reason': 'str' } } =20 diff --git a/block/block-backend.c b/block/block-backend.c index a775a3dd2f..a4421252f8 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1615,10 +1615,11 @@ static void send_qmp_error_event(BlockBackend *blk, bool is_read, int error) { IoOperationType optype; + BlockDriverState *bs =3D blk_bs(blk); =20 optype =3D is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE; - qapi_event_send_block_io_error(blk_name(blk), - bdrv_get_node_name(blk_bs(blk)), optype, + qapi_event_send_block_io_error(blk_name(blk), !!bs, + bs ? bdrv_get_node_name(bs) : NULL, opt= ype, action, blk_iostatus_is_enabled(blk), error =3D=3D ENOSPC, strerror(error), &error_abort); --=20 2.13.6