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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E807FC282E1 for ; Fri, 24 May 2019 22:21:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD34220862 for ; Fri, 24 May 2019 22:21:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RQPcqx6o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404344AbfEXWVP (ORCPT ); Fri, 24 May 2019 18:21:15 -0400 Received: from mail-wr1-f48.google.com ([209.85.221.48]:44298 "EHLO mail-wr1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404332AbfEXWVP (ORCPT ); Fri, 24 May 2019 18:21:15 -0400 Received: by mail-wr1-f48.google.com with SMTP id w13so3015447wru.11; Fri, 24 May 2019 15:21:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:mime-version:message-id:in-reply-to :references:user-agent:content-transfer-encoding; bh=kV6iJR4xfy9BRC6MyG7RFLVo/Wi9XJHicoj8GiJ50zE=; b=RQPcqx6ozrqP8a1MxQY745UDH4f80SGRWFECqSzzyeASqseyw2aQlzRzIn1wiM81sg xsbUtqjNLpiZTDR/k11/K9wPe+t70ZSe1+78iAG390Y/HLpNbDtocRJNNPfHN4GRQG/G AvmvGxT33F/Nounqxq/tVmwfrkbNL2OspUTiWl/KPhxixJkuhxaArg2hRwQ2s4oey+ZJ NXsVa6G+37JjbFSaKF2s6IHQnDl4KXaesPaA5Y9yaTT6QReo1UvSaCciJixjZiMNOaXw z0WWhoz3l/w4vT5on4FVVwrbCe5qkPePBrHdGNYWF/jRUpSTOzW9ACEU42qBBEMl+fXy B1jA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:mime-version:message-id :in-reply-to:references:user-agent:content-transfer-encoding; bh=kV6iJR4xfy9BRC6MyG7RFLVo/Wi9XJHicoj8GiJ50zE=; b=qELDDdwBLBUhiZSa1qgmtr1csFhSTo6VmOy3nw4vY6YY9Fn7zdpgsSqAreN1kXJ7x9 Qeeaj/jjJhd4bQpVdD7GGiV8KmRYExc26AysXeUqa1g/ZFxq90y6pDUiWvQ37sS6gBA9 GUxHH6hvf4BZ7B9Cy5Cl0i8Vl8am0rEsq9LbCHzvqn2uMhIVYUNx8p8ss/4L58zskMHX 1MCyjaMU99dtzAhRTpT6oZZOzFLSpZr01SLhVzhFMUr+eWUsbfu3D+HV4PhSsWqpVzn5 1ZMRN7jdWMs6ZUcZIatXKfbY2IFArdj6gWlA9KW90upIVA82rY8rWboNiIDAD8sR52wS Mgqw== X-Gm-Message-State: APjAAAVQR0YQ73I02Er2Zd1yToNDgBEhVyD5kXW8DG/+1qWjPM3W7NEl +IzXlGqteEKkrpvghNr3CMSYq3qTSCP5Bg== X-Google-Smtp-Source: APXvYqyiO9AqF/rXwvpnWtzQtWh6QNPh6n/g/DmOpGzsA7BmBQUI/Z91rD8hQzpSoz5Dwi9toVKNZg== X-Received: by 2002:a5d:628d:: with SMTP id k13mr7050635wru.319.1558736473197; Fri, 24 May 2019 15:21:13 -0700 (PDT) Received: from localhost ([92.59.185.54]) by smtp.gmail.com with ESMTPSA id l18sm3880043wrv.38.2019.05.24.15.21.11 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 24 May 2019 15:21:12 -0700 (PDT) From: Vicente Bergas To: Al Viro Cc: , Subject: Re: =?iso-8859-1?Q?d=5Flookup:_Unable_to_handle_kernel_paging_request?= Date: Sat, 25 May 2019 00:21:11 +0200 MIME-Version: 1.0 Message-ID: In-Reply-To: <20190522162945.GN17978@ZenIV.linux.org.uk> References: <23950bcb-81b0-4e07-8dc8-8740eb53d7fd@gmail.com> <20190522135331.GM17978@ZenIV.linux.org.uk> <20190522162945.GN17978@ZenIV.linux.org.uk> User-Agent: Trojita Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wednesday, May 22, 2019 6:29:46 PM CEST, Al Viro wrote: > On Wed, May 22, 2019 at 05:44:30PM +0200, Vicente Bergas wrote: > ... > IOW, here we have also run into bogus hlist forward pointer or head - > same 0x1000000 in one case and 0x0000880001000000 in two others. > > Have you tried to see if KASAN catches anything on those loads? > Use-after-free, for example... Another thing to try: slap > =09WARN_ON(entry->d_flags & DCACHE_NORCU); > in __d_rehash() and see if it triggers. Hi, i have been running 3 days with KASAN enabled and also with diff a/fs/dcache.c b/fs/dcache.c @@ -2395,3 +2395,4 @@ static void __d_rehash(struct dentry *entry) =09struct hlist_bl_head *b =3D d_hash(entry->d_name.hash); =20 +=09WARN_ON(entry->d_flags & DCACHE_NORCU); =09hlist_bl_lock(b); but the issue has not appeared again. Next week i will try -rc2 without KASAN and with WARN_ON and see if it triggers. Regards, Vicen=C3=A7.