From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47053) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1vy0-0004R3-Ry for qemu-devel@nongnu.org; Thu, 26 Nov 2015 07:48:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a1vxx-0003WO-IQ for qemu-devel@nongnu.org; Thu, 26 Nov 2015 07:48:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59014) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1vxx-0003W5-DB for qemu-devel@nongnu.org; Thu, 26 Nov 2015 07:48:01 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 14F078A4BC for ; Thu, 26 Nov 2015 12:48:01 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-37.ams2.redhat.com [10.36.116.37]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tAQClx2u026190 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Thu, 26 Nov 2015 07:48:00 -0500 From: Markus Armbruster Date: Thu, 26 Nov 2015 13:47:48 +0100 Message-Id: <1448542078-11690-4-git-send-email-armbru@redhat.com> In-Reply-To: <1448542078-11690-1-git-send-email-armbru@redhat.com> References: <1448542078-11690-1-git-send-email-armbru@redhat.com> Subject: [Qemu-devel] [PULL for-2.5 03/13] qjson: Don't crash when input exceeds nesting limit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org We limit nesting depth and input size to defend against input triggering excessive heap or stack memory use (commit 29c75dd json-streamer: limit the maximum recursion depth and maximum token count). However, when the nesting limit is exceeded, parser_context_peek_token()'s assertion fails. Broken in commit 65c0f1e "json-parser: don't replicate tokens at each level of recursion". To reproduce stuff 1025 open braces or brackets into QMP. Fix by taking the error exit instead of the normal one. Reported-by: Eric Blake Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Message-Id: <1448486613-17634-3-git-send-email-armbru@redhat.com> --- qobject/json-streamer.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c index dced2c7..2bd22a7 100644 --- a/qobject/json-streamer.c +++ b/qobject/json-streamer.c @@ -68,13 +68,14 @@ static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTok /* Security consideration, we limit total memory allocated per object * and the maximum recursion depth that a message can force. */ - goto out_emit; + goto out_emit_bad; } return; out_emit_bad: - /* clear out token list and tell the parser to emit and error + /* + * Clear out token list and tell the parser to emit an error * indication by passing it a NULL list */ QDECREF(parser->tokens); -- 2.4.3