Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63699C433EF for ; Wed, 8 Dec 2021 20:45:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233037AbhLHUsg (ORCPT ); Wed, 8 Dec 2021 15:48:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232827AbhLHUse (ORCPT ); Wed, 8 Dec 2021 15:48:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6A1C061746 for ; Wed, 8 Dec 2021 12:45:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id ADD5CB82285 for ; Wed, 8 Dec 2021 20:45:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C3D5C00446; Wed, 8 Dec 2021 20:44:58 +0000 (UTC) Date: Wed, 8 Dec 2021 15:44:57 -0500 From: Steven Rostedt To: Miaoqian Lin Cc: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] tracing: Fix possible memory leak in __create_synth_event Message-ID: <20211208154457.3a301cf8@gandalf.local.home> In-Reply-To: <20211126104708.7899-1-linmq006@gmail.com> References: <20211126104708.7899-1-linmq006@gmail.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 26 Nov 2021 10:47:08 +0000 Miaoqian Lin wrote: > Before goto err, call argv_free to handle argv in order to prevent > memory leak. > > Signed-off-by: Miaoqian Lin > --- > kernel/trace/trace_events_synth.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c > index 22db3ce95e74..fe2e37564c9b 100644 > --- a/kernel/trace/trace_events_synth.c > +++ b/kernel/trace/trace_events_synth.c > @@ -1261,6 +1261,7 @@ static int __create_synth_event(const char *name, const char *raw_fields) > */ > if (cmd_version > 1 && n_fields_this_loop >= 1) { > synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str)); > + argv_free(argv); > ret = -EINVAL; > goto err; > } > @@ -1268,6 +1269,7 @@ static int __create_synth_event(const char *name, const char *raw_fields) > fields[n_fields++] = field; > if (n_fields == SYNTH_FIELDS_MAX) { > synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); > + argv_free(argv); > ret = -EINVAL; > goto err; > } > @@ -1277,6 +1279,7 @@ static int __create_synth_event(const char *name, const char *raw_fields) > > if (consumed < argc) { > synth_err(SYNTH_ERR_INVALID_CMD, 0); > + argv_free(argv); > ret = -EINVAL; > goto err; > } A cleaner way is to have: diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 98e002648994..a88f1f9046a6 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1237,9 +1237,8 @@ static int __create_synth_event(const char *name, const char *raw_fields) argv + consumed, &consumed, &field_version); if (IS_ERR(field)) { - argv_free(argv); ret = PTR_ERR(field); - goto err; + goto err_free_arg; } /* @@ -1262,26 +1261,25 @@ static int __create_synth_event(const char *name, const char *raw_fields) if (cmd_version > 1 && n_fields_this_loop >= 1) { synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str)); ret = -EINVAL; - goto err; + goto err_free_arg; } fields[n_fields++] = field; if (n_fields == SYNTH_FIELDS_MAX) { synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); ret = -EINVAL; - goto err; + goto err_free_arg; } n_fields_this_loop++; } + argv_free(argv); if (consumed < argc) { synth_err(SYNTH_ERR_INVALID_CMD, 0); ret = -EINVAL; goto err; } - - argv_free(argv); } if (n_fields == 0) { @@ -1307,6 +1305,8 @@ static int __create_synth_event(const char *name, const char *raw_fields) kfree(saved_fields); return ret; + err_free_arg: + argv_free(argv); err: for (i = 0; i < n_fields; i++) free_synth_field(fields[i]); Feel free to send v2 and add: Suggested-by: Steven Rostedt (VMware) -- Steve