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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 CFB7BECDFB8 for ; Fri, 20 Jul 2018 07:53:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 684EE20673 for ; Fri, 20 Jul 2018 07:53:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 684EE20673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727529AbeGTIkY (ORCPT ); Fri, 20 Jul 2018 04:40:24 -0400 Received: from mx3.molgen.mpg.de ([141.14.17.11]:55541 "EHLO mx1.molgen.mpg.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727048AbeGTIkX (ORCPT ); Fri, 20 Jul 2018 04:40:23 -0400 Received: from [192.168.0.5] (ip5f5bd29d.dynamic.kabel-deutschland.de [95.91.210.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id DE98E2012BA076; Fri, 20 Jul 2018 09:53:21 +0200 (CEST) To: Matthew Wilcox Cc: linux-kernel@vger.kernel.org From: Paul Menzel Subject: UBSAN: Undefined behaviour in lib/radix-tree.c:123:14: member access within null pointer of type 'const struct radix_tree_node' Message-ID: <19427cc3-3372-9b02-4b92-096fbe328622@molgen.mpg.de> Date: Fri, 20 Jul 2018 09:53:21 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dear Linux folks, Enabling the undefined behavior sanitizer and building GNU/Linux 4.18-rc5+ (with some unrelated commits) with GCC 8.1.0 from Debian Sid/unstable, the warning below is shown. > [ 0.958688] ================================================================================ > [ 0.959029] UBSAN: Undefined behaviour in lib/radix-tree.c:123:14 > [ 0.959212] member access within null pointer of type 'const struct radix_tree_node' > [ 0.959472] CPU: 0 PID: 24 Comm: kworker/0:2 Not tainted 4.18.0-rc5-00316-g4864b68cedf2 #104 > [ 0.959475] Hardware name: ASROCK E350M1/E350M1, BIOS TIMELESS 01/01/1970 > [ 0.959488] Workqueue: events_power_efficient ioc_release_fn > [ 0.959492] Call Trace: > [ 0.959501] dump_stack+0x55/0x89 > [ 0.959507] ubsan_epilogue+0xb/0x33 > [ 0.959511] handle_null_ptr_deref+0x7f/0x90 > [ 0.959516] __ubsan_handle_type_mismatch_v1+0x55/0x60 > [ 0.959521] __radix_tree_delete+0xc5/0xe0 > [ 0.959525] radix_tree_delete_item+0x5f/0xf0 > [ 0.959529] radix_tree_delete+0xa/0x10 > [ 0.959532] ioc_destroy_icq+0x58/0x1f0 > [ 0.959538] ? free_tty_struct+0x34/0x50 > [ 0.959541] ioc_release_fn+0x9c/0x1a0 > [ 0.959548] process_one_work+0x220/0x700 > [ 0.959553] worker_thread+0x5a/0x690 > [ 0.959557] kthread+0x14e/0x200 > [ 0.959561] ? drain_workqueue+0x290/0x290 > [ 0.959565] ? kthread_create_worker_on_cpu+0x30/0x30 > [ 0.959568] ret_from_fork+0x1c/0x38 > [ 0.959572] ================================================================================ Kind regards, Paul