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 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 04BAFC6778F for ; Wed, 25 Jul 2018 19:29:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD60220893 for ; Wed, 25 Jul 2018 19:29:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD60220893 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 S1730298AbeGYUmL (ORCPT ); Wed, 25 Jul 2018 16:42:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:33478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730068AbeGYUmL (ORCPT ); Wed, 25 Jul 2018 16:42:11 -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 CA988204EC; Wed, 25 Jul 2018 19:29:05 +0000 (UTC) Date: Wed, 25 Jul 2018 15:29:04 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: LKML , Tom Zanussi , Hiraku Toyooka , Ingo Molnar , Andrew Morton Subject: Re: [PATCH] tracing: Fix double free of event_trigger_data Message-ID: <20180725152904.11edde2b@gandalf.local.home> In-Reply-To: <20180725124008.7008e586@gandalf.local.home> References: <20180725085740.5e7efaa1@gandalf.local.home> <20180726004349.e71303133ff8e095a1a1499e@kernel.org> <20180725124008.7008e586@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 25 Jul 2018 12:40:08 -0400 Steven Rostedt wrote: > Hmm, looks to me that event_enable_trigger_func() suffers the same > issue. Perhaps we should add this patch too: > > -- Steve > > diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c > index d18ec0e58be2..2681d917f896 100644 > --- a/kernel/trace/trace_events_trigger.c > +++ b/kernel/trace/trace_events_trigger.c > @@ -1457,6 +1457,10 @@ int event_enable_trigger_func(struct event_command *cmd_ops, > ret = trace_event_enable_disable(event_enable_file, 1, 1); > if (ret < 0) > goto out_put; > + > + /* Up the trigger_data count to make sure reg doesn't free it on failure */ > + event_trigger_init(trigger_ops, trigger_data); > + > ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); > /* > * The above returns on success the # of functions enabled, > @@ -1464,12 +1468,13 @@ int event_enable_trigger_func(struct event_command *cmd_ops, > * Consider no functions a failure too. > */ > if (!ret) { > + cmd_ops->unreg(glob, trigger_ops, trigger_data, file); > ret = -ENOENT; > - goto out_disable; > - } else if (ret < 0) > - goto out_disable; > - /* Just return zero, not the number of enabled functions */ > - ret = 0; > + } else if (ret > 0) > + ret = 0; > + > + /* Down the counter of trigger_data or free it if not used anymore */ > + event_trigger_free(trigger_ops, trigger_data); Nope, this doesn't work. It's a little more complex than the other one. I'll just leave it, and fix the reg code for 4.19. -- Steve > out: > return ret; >