Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753170AbdLPJR0 (ORCPT ); Sat, 16 Dec 2017 04:17:26 -0500 Received: from mail-wm0-f48.google.com ([74.125.82.48]:42552 "EHLO mail-wm0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907AbdLPJRV (ORCPT ); Sat, 16 Dec 2017 04:17:21 -0500 X-Google-Smtp-Source: ACJfBosMH0F/vO9zyFoPbMpRDVKnSQCgYccmaCQhItUiSyxMzQ3URe5l0DgLf+C/QzAb0tIMVyZIwA== Subject: Re: BUG: unable to handle kernel NULL pointer dereference in fdb_find_rcu To: Andrei Vagin , Linux Kernel Network Developers , LKML References: From: Nikolay Aleksandrov Message-ID: <415b4093-4c58-c671-0df1-a6f650414416@cumulusnetworks.com> Date: Sat, 16 Dec 2017 11:17:17 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 598 Lines: 21 On 16/12/17 02:37, Andrei Vagin wrote: > Hi, > > We run criu tests for linux-next and today we get this bug: > > The kernel version is 4.15.0-rc3-next-20171215 > > [ 235.397328] BUG: unable to handle kernel NULL pointer dereference > at 000000000000000c > [ 235.398624] IP: fdb_find_rcu+0x3c/0x130 [snip] Hi, Thanks for the report, I've missed the changelink before dev creation case when I did the rhashtable conversion, some of the options do fdb lookups as part of their routine but we don't have the table initialized yet at that point. I'll send a fix after some testing. Thanks, Nik