From patchwork Sun Nov 20 20:07:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 23455 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp1250613wrr; Sun, 20 Nov 2022 12:09:17 -0800 (PST) X-Google-Smtp-Source: AA0mqf4cAR49FCEyWjNwDzB/rbIKdhagchb8qIhbsbCLIAFvV/zb2T+Arvf9JCuSwyABxqWtADqz X-Received: by 2002:aa7:9192:0:b0:563:1ae2:6daf with SMTP id x18-20020aa79192000000b005631ae26dafmr532760pfa.71.1668974957390; Sun, 20 Nov 2022 12:09:17 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1668974957; cv=none; d=google.com; s=arc-20160816; b=oe6iNI5ZIU1BKZKSiwR4fRDYjoT4/apfhvgSKw8RHPzyBmcl3NN1Nxt/TRXWgmK0Bb ZgwcYkhWNF9kMawGs0bv5nNoui1k0bu9lrJqtx36CoVxMalhEHi+l0epPWzlQu5qdmjl pam9o6Xqeb3o3GStCtkZQm787oOsvaBMHx3jUNHB0SjAHrvDG5zjCCXSOr7k49EILyIl f8J31LE4QZME2H/Z4U7LIh5X48WRaoNZv7Kpn4Dytt7MouAyR6lwW4Fu/1fZKcW1epH3 6OPXW9pC4zWs5IOZqGTlVxgbwgYc21nwcWKcWEd0nW3fXXjMvbHpK6Sdq9Y99hCYvBgy qRKQ== 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=YBdY1J0aGQI06CfhPu5T9CBMwUlbMbR7N5+wVq351QY=; b=iflzVvyw5sM2Mow1wvYrv4sDERY5z8F7OtweNzO1Via6ulO5DXt/y943VPmiwhOXlh 1Z0/nZ2ZzmbMP7WhbEsPXPIBMxw/FouFfQNJPjM1Nhzv5umbByLqwPt1QPvBQeaRBbpS dEZa582X3+nP7EQQFBdRNkXuH5Jc7I8Knky7iG5b4tuUnq5duEjgj4mj/5p4r21Zdccw 0Q0xk8I3qpP6/3THblE67xmvBFBiuo/LtZkQuXMdlJFBz9SjmOWXzTaFPdPgiwNYudSU A0HjALeHpWb3CDJUBT+fFvh0BItINnb2NlLl3LCqMQPT1n0pwD+a9AkBZTh76fE+t+Al ILXg== 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 d8-20020a056a0010c800b00557e3e7c420si10201109pfu.213.2022.11.20.12.09.04; Sun, 20 Nov 2022 12:09:17 -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 S229871AbiKTUIW (ORCPT + 99 others); Sun, 20 Nov 2022 15:08:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229747AbiKTUHk (ORCPT ); Sun, 20 Nov 2022 15:07:40 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B079F1E713 for ; Sun, 20 Nov 2022 12:07:38 -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 dfw.source.kernel.org (Postfix) with ESMTPS id D76E660D2E for ; Sun, 20 Nov 2022 20:07:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1287C433D6; Sun, 20 Nov 2022 20:07:36 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1owqbH-00Di9F-2U; Sun, 20 Nov 2022 15:07:35 -0500 Message-ID: <20221120200735.618733319@goodmis.org> User-Agent: quilt/0.66 Date: Sun, 20 Nov 2022 15:07:12 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , Zheng Yejian Subject: [for-linus][PATCH 12/13] tracing: Fix potential null-pointer-access of entry in list tr->err_log References: <20221120200700.725968899@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?1750047084824085572?= X-GMAIL-MSGID: =?utf-8?q?1750047084824085572?= From: Zheng Yejian Entries in list 'tr->err_log' will be reused after entry number exceed TRACING_LOG_ERRS_MAX. The cmd string of the to be reused entry will be freed first then allocated a new one. If the allocation failed, then the entry will still be in list 'tr->err_log' but its 'cmd' field is set to be NULL, later access of 'cmd' is risky. Currently above problem can cause the loss of 'cmd' information of first entry in 'tr->err_log'. When execute `cat /sys/kernel/tracing/error_log`, reproduce logs like: [ 37.495100] trace_kprobe: error: Maxactive is not for kprobe(null) ^ [ 38.412517] trace_kprobe: error: Maxactive is not for kprobe Command: p4:myprobe2 do_sys_openat2 ^ Link: https://lore.kernel.org/linux-trace-kernel/20221114104632.3547266-1-zhengyejian1@huawei.com Fixes: 1581a884b7ca ("tracing: Remove size restriction on tracing_log_err cmd strings") Signed-off-by: Zheng Yejian Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5bd202d6d79a..a7fe0e115272 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7803,6 +7803,7 @@ static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr, int len) { struct tracing_log_err *err; + char *cmd; if (tr->n_err_log_entries < TRACING_LOG_ERRS_MAX) { err = alloc_tracing_log_err(len); @@ -7811,12 +7812,12 @@ static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr, return err; } - + cmd = kzalloc(len, GFP_KERNEL); + if (!cmd) + return ERR_PTR(-ENOMEM); err = list_first_entry(&tr->err_log, struct tracing_log_err, list); kfree(err->cmd); - err->cmd = kzalloc(len, GFP_KERNEL); - if (!err->cmd) - return ERR_PTR(-ENOMEM); + err->cmd = cmd; list_del(&err->list); return err;