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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable 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 CF185C432BE for ; Fri, 30 Jul 2021 22:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A787C60F42 for ; Fri, 30 Jul 2021 22:41:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232948AbhG3Wlc (ORCPT ); Fri, 30 Jul 2021 18:41:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:32818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231189AbhG3Wlb (ORCPT ); Fri, 30 Jul 2021 18:41:31 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 527EA60524; Fri, 30 Jul 2021 22:41:25 +0000 (UTC) Date: Fri, 30 Jul 2021 18:41:18 -0400 From: Steven Rostedt To: Kamal Agrawal Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, mhiramat@kernel.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH] tracing: Fix NULL pointer dereference in start_creating Message-ID: <20210730184118.0ea8ef20@oasis.local.home> In-Reply-To: <1627651386-21315-1-git-send-email-kamaagra@codeaurora.org> References: <1627651386-21315-1-git-send-email-kamaagra@codeaurora.org> X-Mailer: Claws Mail 3.17.3 (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, 30 Jul 2021 18:53:06 +0530 Kamal Agrawal wrote: > The event_trace_add_tracer() can fail. In this case, it leads to a crash > in start_creating with below call stack. Handle the error scenario > properly in trace_array_create_dir. > > Call trace: > down_write+0x7c/0x204 > start_creating.25017+0x6c/0x194 > tracefs_create_file+0xc4/0x2b4 > init_tracer_tracefs+0x5c/0x940 > trace_array_create_dir+0x58/0xb4 > trace_array_create+0x1bc/0x2b8 > trace_array_get_by_name+0xdc/0x18c > > Fixes: 4114fbfd Thanks, I'll queue this up. -- Steve > Signed-off-by: Kamal Agrawal > --- > kernel/trace/trace.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index c59dd35..33899a7 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -9135,8 +9135,10 @@ static int trace_array_create_dir(struct trace_array *tr) > return -EINVAL; > > ret = event_trace_add_tracer(tr->dir, tr); > - if (ret) > + if (ret) { > tracefs_remove(tr->dir); > + return ret; > + } > > init_tracer_tracefs(tr, tr->dir); > __update_tracer_options(tr);