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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 10397C43142 for ; Sat, 23 Jun 2018 01:21:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BFAD624A76 for ; Sat, 23 Jun 2018 01:21:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BFAD624A76 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934588AbeFWBVK (ORCPT ); Fri, 22 Jun 2018 21:21:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:43268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933841AbeFWBVG (ORCPT ); Fri, 22 Jun 2018 21:21:06 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 100EC24A6C; Sat, 23 Jun 2018 01:21:06 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.91) (envelope-from ) id 1fWXEf-0008Q9-33; Fri, 22 Jun 2018 21:21:05 -0400 Message-Id: <20180623012104.986961735@goodmis.org> User-Agent: quilt/0.65 Date: Fri, 22 Jun 2018 21:20:36 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Ingo Molnar , Andrew Morton , stable@vger.kernel.org, air icy Subject: [PATCH 1/5] tracing: Check for no filter when processing event filters MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0001-tracing-Check-for-no-filter-when-processing-event-fi.patch Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" The syzkaller detected a out-of-bounds issue with the events filter code, specifically here: prog[N].pred = NULL; /* #13 */ prog[N].target = 1; /* TRUE */ prog[N+1].pred = NULL; prog[N+1].target = 0; /* FALSE */ -> prog[N-1].target = N; prog[N-1].when_to_branch = false; As that's the first reference to a "N-1" index, it appears that the code got here with N = 0, which means the filter parser found no filter to parse (which shouldn't ever happen, but apparently it did). Add a new error to the parsing code that will check to make sure that N is not zero before going into this part of the code. If N = 0, then -EINVAL is returned, and a error message is added to the filter. Cc: stable@vger.kernel.org Fixes: 80765597bc587 ("tracing: Rewrite filter logic to be simpler and faster") Reported-by: air icy bugzilla url: https://bugzilla.kernel.org/show_bug.cgi?id=200019 Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_filter.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index e1c818dbc0d7..0dceb77d1d42 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -78,7 +78,8 @@ static const char * ops[] = { OPS }; C(TOO_MANY_PREDS, "Too many terms in predicate expression"), \ C(INVALID_FILTER, "Meaningless filter expression"), \ C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \ - C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), + C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), \ + C(NO_FILTER, "No filter found"), #undef C #define C(a, b) FILT_ERR_##a @@ -550,6 +551,13 @@ predicate_parse(const char *str, int nr_parens, int nr_preds, goto out_free; } + if (!N) { + /* No program? */ + ret = -EINVAL; + parse_error(pe, FILT_ERR_NO_FILTER, ptr - str); + goto out_free; + } + prog[N].pred = NULL; /* #13 */ prog[N].target = 1; /* TRUE */ prog[N+1].pred = NULL; -- 2.17.1