From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47841) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fdZWN-000778-KV for qemu-devel@nongnu.org; Thu, 12 Jul 2018 07:12:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fdZWL-0006ol-4k for qemu-devel@nongnu.org; Thu, 12 Jul 2018 07:12:27 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47654 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 1fdZWK-0006ny-S1 for qemu-devel@nongnu.org; Thu, 12 Jul 2018 07:12:24 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 882E0406DE36 for ; Thu, 12 Jul 2018 11:12:24 +0000 (UTC) From: Markus Armbruster Date: Thu, 12 Jul 2018 13:12:10 +0200 Message-Id: <20180712111221.20326-10-armbru@redhat.com> In-Reply-To: <20180712111221.20326-1-armbru@redhat.com> References: <20180712111221.20326-1-armbru@redhat.com> Subject: [Qemu-devel] [PATCH 09/20] qobject: qobject_from_jsonv() is dangerous, hide it away List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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 --- 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 0db121bef9..4a225cf7d1 100644 --- a/include/qapi/qmp/qjson.h +++ b/include/qapi/qmp/qjson.h @@ -15,8 +15,6 @@ #define QJSON_H 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); QObject *qobject_from_vjsonf_nofail(const char *string, va_list) 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 = json_parser_parse_err(tokens, s->ap, &s->err); } -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 = {}; -- 2.17.1