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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 3267AC4338F for ; Tue, 10 Aug 2021 18:03:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 100CA604D7 for ; Tue, 10 Aug 2021 18:03:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235828AbhHJSDU (ORCPT ); Tue, 10 Aug 2021 14:03:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:60118 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237585AbhHJSBT (ORCPT ); Tue, 10 Aug 2021 14:01:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BBC62613B1; Tue, 10 Aug 2021 17:46:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628617619; bh=1oExI4xT1X0DgvO44tr3R7Kv855uBCclom3Awv+5h/8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FRMB7DZcSg4fg37ZaVVr6vhNJb7staWz7lq2y9F+63q7XhB3o+CNOm67Wh1g3XQtr Az1Hn061hcb2fOEt/o1P748tn28qQf7xkh8J5I5kfcPPxpgBDQOkJg2+UoztL+hZPK yY++Lpx5Ha/1D0Hi3bjILBMOJKY6zK6g9BK31pKQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kamal Agrawal , "Steven Rostedt (VMware)" Subject: [PATCH 5.13 104/175] tracing: Fix NULL pointer dereference in start_creating Date: Tue, 10 Aug 2021 19:30:12 +0200 Message-Id: <20210810173004.392950614@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810173000.928681411@linuxfoundation.org> References: <20210810173000.928681411@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kamal Agrawal commit ff41c28c4b54052942180d8b3f49e75f1445135a upstream. 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 Link: https://lkml.kernel.org/r/1627651386-21315-1-git-send-email-kamaagra@codeaurora.org Cc: stable@vger.kernel.org Fixes: 4114fbfd02f1 ("tracing: Enable creating new instance early boot") Signed-off-by: Kamal Agrawal Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9006,8 +9006,10 @@ static int trace_array_create_dir(struct 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);