From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yonghong Song Subject: Re: oops with ip6_rt_cache_alloc Date: Sun, 26 Aug 2018 21:57:40 -0700 Message-ID: <4f7ab12f-37c2-5bdc-5993-be8da71ec0de@fb.com> References: <5d3d7d56-ce9f-79c3-04ec-122a2451b580@fb.com> <2314c9c2-27ab-c470-5e8a-4e28e53810b2@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit To: David Ahern , netdev , Alexei Starovoitov , Martin Lau , Dave Jones Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:40984 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726714AbeH0Imt (ORCPT ); Mon, 27 Aug 2018 04:42:49 -0400 In-Reply-To: <2314c9c2-27ab-c470-5e8a-4e28e53810b2@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 8/24/18 4:04 PM, David Ahern wrote: > On 8/24/18 4:26 PM, Yonghong Song wrote: >> Hi, >> >> We got a kernel oops with the following stack trace: >> >> CPU: 24 PID: 0 Comm: swapper/24 Not tainted >> 4.16.0-10_fbk1_1183_g7e4ee4c8171c #10 >> "Hardware name: Quanta Leopard-DDR3/Leopard-DDR3, BIOS F06_3A16.DDR3 >> 11/19/2015" >> RIP: 0010:ip6_rt_get_dev_rcu+0x6/0x60 >> RSP: 0018:ffff88046fb03c78 EFLAGS: 00010286 >> RAX: 0000000040000003 RBX: ffff88035a6c1500 RCX: ffffffff81ec5dc0 >> RDX: ffff88033192a090 RSI: ffff88033192a0a0 RDI: 0000000000000000 > > RDI = 0 means the rt passed to ip6_rt_get_dev_rcu is NULL. I believe > that can't happen prior to the fib6_info changes. After the fib6_info > changes, it means the 'from' is NULL and that is not expected. > > ... > >> Our internal experiments showed that an early version of 4.16 works fine >> and after backporting some ipv6 route related changes and the above >> problem showed up. > > Can you run the test on 4.18? We will give a try with 4.18. Thanks.