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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 EFCC7C433E0 for ; Wed, 1 Jul 2020 07:39:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E26C20773 for ; Wed, 1 Jul 2020 07:39:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=tu-berlin.de header.i=@tu-berlin.de header.b="f0cR+J2X" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728195AbgGAHjW (ORCPT ); Wed, 1 Jul 2020 03:39:22 -0400 Received: from exchange.tu-berlin.de ([130.149.7.70]:12603 "EHLO exchange.tu-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727836AbgGAHjW (ORCPT ); Wed, 1 Jul 2020 03:39:22 -0400 Received: from SPMA-01.tubit.win.tu-berlin.de (localhost.localdomain [127.0.0.1]) by localhost (Email Security Appliance) with SMTP id D97DD7DEC68_EFC3DA5B; Wed, 1 Jul 2020 07:39:17 +0000 (GMT) Received: from exchange.tu-berlin.de (exchange.tu-berlin.de [130.149.7.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (Client CN "exchange.tu-berlin.de", Issuer "DFN-Verein Global Issuing CA" (not verified)) by SPMA-01.tubit.win.tu-berlin.de (Sophos Email Appliance) with ESMTPS id 6F9AF7DEC63_EFC3DA5F; Wed, 1 Jul 2020 07:39:17 +0000 (GMT) Received: from ex-01.tubit.win.tu-berlin.de (172.26.35.184) by ex-mbx-10.tubit.win.tu-berlin.de (172.26.35.180) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 1 Jul 2020 09:39:17 +0200 Received: from ex-02.tubit.win.tu-berlin.de (172.26.35.185) by ex-01.tubit.win.tu-berlin.de (172.26.35.184) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.529.5; Wed, 1 Jul 2020 09:39:15 +0200 Received: from ex-02.tubit.win.tu-berlin.de ([172.26.26.142]) by ex-02.tubit.win.tu-berlin.de ([172.26.26.142]) with mapi id 15.02.0529.008; Wed, 1 Jul 2020 09:39:14 +0200 From: "Kraus, Sebastian" To: Doug Nazar CC: "linux-nfs@vger.kernel.org" , "J. Bruce Fields" Subject: Re: [PATCH v2] Re: Strange segmentation violations of rpc.gssd in Debian Buster Thread-Topic: [PATCH v2] Re: Strange segmentation violations of rpc.gssd in Debian Buster Thread-Index: AQHWSxgxwlq3b/mulkebnqBRRSeMOajpu9IAgAEVEpGAADSGAIAAJ84AgAAINwCAAA0egIAAB7GAgAPJdTGAAHJrgIAC0LGM Date: Wed, 1 Jul 2020 07:39:14 +0000 Message-ID: <94422f073b7e4b979931e6d8d3a0c044@tu-berlin.de> References: <28a44712b25c4420909360bd813f8bfd@tu-berlin.de> <20200620170316.GH1514@fieldses.org> <5c45562c90404838944ee71a1d926c74@tu-berlin.de> <20200622223628.GC11051@fieldses.org> <406fe972135846dc8a23b60be59b0590@tu-berlin.de> <1527b158-3404-168c-8908-de4b8a709ccd@nazar.ca> <20200626194622.GB11850@fieldses.org> <3eb80b1f-e4d3-e87c-aacd-34dc28637948@nazar.ca> <20200626210243.GD11850@fieldses.org> <6cf63c80f285495d8328c5c8b55fc9d6@tu-berlin.de>,<41614030-a616-1ad0-280c-7e24342cd455@nazar.ca> In-Reply-To: <41614030-a616-1ad0-280c-7e24342cd455@nazar.ca> Accept-Language: en-US, de-DE Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [91.64.112.104] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-PMWin-Version: 4.0.1, Antivirus-Engine: 3.77.1, Antivirus-Data: 5.76 X-PureMessage: [Scanned] X-SASI-RCODE: 200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tu-berlin.de; h=from:to:cc:subject:date:message-id:references:in-reply-to:content-type:content-transfer-encoding:mime-version; s=dkim-tub; bh=M4q1JzEyb50Ult3ew/mYoyxqvYEvxt4mmMxD1ky6r4M=; b=f0cR+J2Xjt1VrwU/t90fas1GZyxKGP7/X/s9hDDsqZ9N+C3uTJVWNeEtB5SCPN/Rj2FJwlc+VZJIfUjRAds14DbsCtsYQ1sybBr77Y+vBNn8w6i3qr/BZ8JSAtTRu4BObIxlwSM5rzH99BLC4QvFGlGqhM5QFKuWgp9ZTAnhfl4= Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Hi Doug, >> Yes, I'm working against upstream. I did check briefly that the code had= n't changed too much since 1.3.4 in that area. OK, thanks for the info. I wondered, because your patch did not show up as = a commit within upstream.=20 Your patch seems to do a good job - no more segfaults since a period of fou= r days. :-) >> I've found one other place that has insufficient locking but the race to= hit it is fairly small. It's in the Kerberos machine principal cache when = it refreshes the machine credentials.=20 These type of patches are always welcome. :-) In the recent past, some of our scientific staff exprienced strange problem= s with Kerberos authentication against our NFSv4 file servers.=20 Maybe, the outages were in connection with this type of race condition. But= , I do not know for sure as the authentication errors did happen on a rathe= r sporadic basis. >> I have a patch for that, but it's pretty invasive due to some other chan= ges I'm currently working on. Let me know if you hit it, and I can work on = a simple version to backport. NFSv4+Kerberos is not for the faint-hearted. I do not fear of invasive patc= hes - as long as they are not missing technical correctness. ;-) A question far apart from this: How is it about the spread of NFSv4+Kerberos setups within academic communi= ty and commerical environments?=20 Are there, up to your knowledge, any bigger on-premise or cloud setups out = there? And are there any companies running dedicated NFSv4+Kerberos setups? Best and keep well and fit Sebastian _________________ Sebastian Kraus Team IT am Institut f=FCr Chemie Geb=E4ude C, Stra=DFe des 17. Juni 115, Raum C7 Technische Universit=E4t Berlin Fakult=E4t II Institut f=FCr Chemie Sekretariat C3 Stra=DFe des 17. Juni 135 10623 Berlin Tel.: +49 30 314 22263 Fax: +49 30 314 29309 Email: sebastian.kraus@tu-berlin.de ________________________________________ From: Doug Nazar Sent: Monday, June 29, 2020 16:09 To: Kraus, Sebastian Cc: linux-nfs@vger.kernel.org Subject: Re: [PATCH v2] Re: Strange segmentation violations of rpc.gssd in = Debian Buster On 2020-06-29 01:39, Kraus, Sebastian wrote: > Hi Doug, > thanks very much for your patch and efforts. > I manually backported the patch to nfs-utils 1.3.4-2.5 source in Debian B= uster. > I am now testing the modified build on one of my NFSv4 file servers. Look= s promising. > > One additional question: Which nfs-utils branch are your working on - ste= ved/nfs-utils.git ? Yes, I'm working against upstream. I did check briefly that the code hadn't changed too much since 1.3.4 in that area. I've found one other place that has insufficient locking but the race to hit it is fairly small. It's in the Kerberos machine principal cache when it refreshes the machine credentials. I have a patch for that, but it's pretty invasive due to some other changes I'm currently working on. Let me know if you hit it, and I can work on a simple version to backport. Doug