From patchwork Sat Dec 10 14:03:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 32038 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp1341505wrr; Sat, 10 Dec 2022 06:34:41 -0800 (PST) X-Google-Smtp-Source: AA0mqf4O84wUQ6TaA/tad7w6/7TLwyQOuCF4WxG3cki8fDegNbR/9rvx4fUEOi+1PY062M13hjkW X-Received: by 2002:a05:6402:3646:b0:45c:a5f2:ffea with SMTP id em6-20020a056402364600b0045ca5f2ffeamr9427408edb.7.1670681734112; Sat, 10 Dec 2022 06:15:34 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1670681734; cv=none; d=google.com; s=arc-20160816; b=Hd5y6OH7NIlPE5bQ/ZF6tfmLeyqql50MRUtZpFY13M2OuCKYlNUfQ8e8xaJxG1AUn5 XcDiKHO64wdw3cdOgttflgx+H790CDkRySBKxwhKL/8bUYt9dMzOkvo7+fC0XQxVtUyP ybij+DY2pG93a6P0pOWTC4HwS/Af2IC7NbZ+BOtOnuxs6zFkl5xHMujGnDatj0bJUkSi WmvaO89dVDEggSCuyNxolDGNwD2ULgFO9OI8+AItU2ASn/ObOcV3fHfGhoxJsSWV7ISA IDGc/YkTTRM0ZDDffE0zdLPsZS3V2KPXUmVy86L+RNUm6Njo+2/1sGTvHOKMVpS4Ud4x UI0g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:references:subject:cc:to:from:date :user-agent:message-id; bh=x1VsP2zPZYGCdmtwtOZYR7abc4KJc5fwT7pIdgXuy98=; b=FULIaONkLmnvgnrOq3duRpQk/sGZAO7WKF+yc0DfXkwMA8tV4VNELJQekDHYdRNP7Z WfZEMtksur92jZU8Wo1GI0LxMpFYtaNtgt5kC7oap4z9TQsfhySiYcRCq/kuPJv8GkND I1K0vyrf2KGc+DWXGLp3NeCnPrqgrsi9H4ojJEzggVsKrpqqanYksmv8a4P2DpTnbLLx JnYyhoCnJYMt9QZ42WlheZ/9AvQUoDjTf7AaBzoF1yzpIp/md9hLceXtkFtSxNbtf5ig r+79FPFMK6dJgjRrfQsLmt0hHRvsquEaNhZ5+VIpwcdjWacRdIfNRuKNlh+SvG3H48g1 uvUQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id ji15-20020a170907980f00b007c0b03b23b5si2469888ejc.542.2022.12.10.06.15.11; Sat, 10 Dec 2022 06:15:34 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229914AbiLJOHn (ORCPT + 99 others); Sat, 10 Dec 2022 09:07:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230048AbiLJOGx (ORCPT ); Sat, 10 Dec 2022 09:06:53 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 917791BE98; Sat, 10 Dec 2022 06:03:56 -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 38701B82A56; Sat, 10 Dec 2022 14:03:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAC70C433D2; Sat, 10 Dec 2022 14:03:53 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1p40SG-000l40-39; Sat, 10 Dec 2022 09:03:52 -0500 Message-ID: <20221210140352.840122725@goodmis.org> User-Agent: quilt/0.66 Date: Sat, 10 Dec 2022 09:03:21 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , stable@vger.kernel.org, Rafael Mendonca Subject: [for-next][PATCH 1/3] tracing: Fix race where eprobes can be called before the event References: <20221210140320.609495935@goodmis.org> MIME-Version: 1.0 X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1751836769954224167?= X-GMAIL-MSGID: =?utf-8?q?1751836769954224167?= From: "Steven Rostedt (Google)" The flag that tells the event to call its triggers after reading the event is set for eprobes after the eprobe is enabled. This leads to a race where the eprobe may be triggered at the beginning of the event where the record information is NULL. The eprobe then dereferences the NULL record causing a NULL kernel pointer bug. Test for a NULL record to keep this from happening. Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/ Link: https://lore.kernel.org/all/20221117214249.2addbe10@gandalf.local.home/ Cc: stable@vger.kernel.org Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Reported-by: Rafael Mendonca Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_eprobe.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 123d2c0a6b68..352b65e2b910 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -564,6 +564,9 @@ static void eprobe_trigger_func(struct event_trigger_data *data, { struct eprobe_data *edata = data->private_data; + if (unlikely(!rec)) + return; + __eprobe_trace_func(edata, rec); }