From nobody Wed Nov 5 00:19:32 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 15335389233047.466791135968833; Mon, 6 Aug 2018 00:02:03 -0700 (PDT) Received: from localhost ([::1]:60990 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fmZWc-0000DG-Km for importer@patchew.org; Mon, 06 Aug 2018 03:01:54 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33316) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fmZOp-0001XQ-5R for qemu-devel@nongnu.org; Mon, 06 Aug 2018 02:53:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fmZOm-00087n-FC for qemu-devel@nongnu.org; Mon, 06 Aug 2018 02:53:51 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35604 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 1fmZOm-00087H-7E for qemu-devel@nongnu.org; Mon, 06 Aug 2018 02:53:48 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B6C0481663F1; Mon, 6 Aug 2018 06:53:47 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-117-62.ams2.redhat.com [10.36.117.62]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 412DC16878; Mon, 6 Aug 2018 06:53:47 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id AAD1A1138667; Mon, 6 Aug 2018 08:53:44 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Mon, 6 Aug 2018 08:53:31 +0200 Message-Id: <20180806065344.7103-11-armbru@redhat.com> In-Reply-To: <20180806065344.7103-1-armbru@redhat.com> References: <20180806065344.7103-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 06 Aug 2018 06:53:47 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 06 Aug 2018 06:53:47 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'armbru@redhat.com' RCPT:'' Content-Transfer-Encoding: quoted-printable 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 v3 10/23] qobject: qobject_from_jsonv() is dangerous, hide it away 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: thuth@redhat.com, f4bug@amsat.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" qobject_from_jsonv() takes ownership of %p arguments. On failure, we can't generally know whether we failed before or after %p, so ownership becomes indeterminate. To avoid leaks, callers passing %p must terminate on error, e.g. by passing &error_abort. Trap for the unwary; document and give the function internal linkage. Signed-off-by: Markus Armbruster Reviewed-by: Philippe Mathieu-Daud=C3=A9 Reviewed-by: Eric Blake --- include/qapi/qmp/qjson.h | 2 -- qobject/qjson.c | 13 ++++++++++++- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/include/qapi/qmp/qjson.h b/include/qapi/qmp/qjson.h index dce78583dc..5ebbe5a118 100644 --- a/include/qapi/qmp/qjson.h +++ b/include/qapi/qmp/qjson.h @@ -15,8 +15,6 @@ #define QJSON_H =20 QObject *qobject_from_json(const char *string, Error **errp); -QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp) - GCC_FMT_ATTR(1, 0); =20 QObject *qobject_from_vjsonf_nofail(const char *string, va_list ap) GCC_FMT_ATTR(1, 0); diff --git a/qobject/qjson.c b/qobject/qjson.c index 2e450231ff..ab4040f235 100644 --- a/qobject/qjson.c +++ b/qobject/qjson.c @@ -39,7 +39,18 @@ static void parse_json(JSONMessageParser *parser, GQueue= *tokens) s->result =3D json_parser_parse_err(tokens, s->ap, &s->err); } =20 -QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp) +/* + * Parse @string as JSON value. + * If @ap is non-null, interpolate %-escapes. + * Takes ownership of %p arguments. + * On success, return the JSON value. + * On failure, store an error through @errp and return NULL. + * Ownership of %p arguments becomes indeterminate then. To avoid + * leaks, callers passing %p must terminate on error, e.g. by passing + * &error_abort. + */ +static QObject *qobject_from_jsonv(const char *string, va_list *ap, + Error **errp) { JSONParsingState state =3D {}; =20 --=20 2.17.1