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,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 0557EC43603 for ; Tue, 17 Dec 2019 12:56:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 948DC20663 for ; Tue, 17 Dec 2019 12:56:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ts.fujitsu.com header.i=@ts.fujitsu.com header.b="RdeM+gcV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727780AbfLQM4j (ORCPT ); Tue, 17 Dec 2019 07:56:39 -0500 Received: from mail3.bemta25.messagelabs.com ([195.245.230.88]:59851 "EHLO mail3.bemta25.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726141AbfLQM4j (ORCPT ); Tue, 17 Dec 2019 07:56:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ts.fujitsu.com; s=200619tsfj; t=1576587396; i=@ts.fujitsu.com; bh=fpkvNtzpSQbdWK6I0VIWWEXa6W4Wxi8aXY9BJ5Mg5Q0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding:Content-Type; b=RdeM+gcVOTFvbn2ck8Nmca1G7PZ5vVFdGPIDvyrKHtvuppCa7jicgMjLOClcOVg0N Rx2jTXpWS+Q1LeARetPUzvIWIjdn3TIvGeyEWKQAo9H1kDai8mVW98Vg8EEoi7eFkD 2E8vlW6dKIYGkJ2KGYAIPnkpzwsK5z0gCECJjpq6TiE58EXxIR7JwGosAsDWJvY/kn baUhkqXs7uUi0pjYm3kXI/fZBPgxudDw1dBc9c7gPjYqF7bFv5cYmbk+ZWz42Gu+vz Zc1hEryQEvwR7Zg0zkX2oHkDV9+hrXpDp/tXNg9oa/3xuSnJAEepVokVXGNlirkMjf RRAlZQ4zPw/+Q== Received: from [46.226.52.197] (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits)) by server-8.bemta.az-b.eu-west-1.aws.symcld.net id FF/4B-22072-380D8FD5; Tue, 17 Dec 2019 12:56:35 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrBIsWRWlGSWpSXmKPExsViZ8MRqtt84Ue swZULChbHJ1ha7Nl7ksXi8q45bBaTOo+xObB4tGyO9ph3MtDj8ya5AOYo1sy8pPyKBNaM0zP1 C16wV3TemMXSwLiSrYuRi0NIYA6jxJkTf1kgnHmMEquOXmDtYuTkYBMwkNj16hAziC0ioCzx5 MB6MJtZIENi74XnTCC2sICHxOa9bxlBbBYBVYlrW96AxXkFDCVOrTwGVs8poCvx+OY+dhBbSC BIYsrzxYwQNYISJ2c+YYGYKS/RcbmRFcLWkViw+xPbBEbeWUjKZiEpm4WkbAEj8ypGi6SizPS MktzEzBxdQwMDXUNDI11DSzNdIwMjvcQq3SS91FLd8tTiEl1DvcTyYr3iytzknBS9vNSSTYzA AE0pOHJqB+Ohr2/1DjFKcjApifK+3fkjVogvKT+lMiOxOCO+qDQntfgQowwHh5IE779zQDnBo tT01Iq0zBxgtMCkJTh4lER4Oc8DpXmLCxJzizPTIVKnGBWlxHlngfQJgCQySvPg2mAReolRVk qYl5GBgUGIpyC1KDezBFX+FaM4B6OSMK8TyBSezLwSuOmvgBYzAS028vsGsrgkESEl1cAU83r CNDHW5HrPp8Lcp60OT2SNN3TaNOW5peC9LVzr918N/JRRqucWdmXJEXlrkeqdyuvfd/32cHnj +C/++4e8mERx5d09T4smf193+ibDrpxrmf8SQ9zM99u/0fyzpHPTpA7r4wobL59jFSqZb3zWN PjKl53lbJEZ4Zesml6UfOer1LobFP73weNVRdYP/143Pi9autHWUjzh9rtZ9lGcBxsnnJ6921 BnCb/O7eimr3d2Z9r+MWnfte79Fe8lxxRT7rNNvPTBennWvtjm27nnZTUXcU5dM9lCdE/c3hq Vz1z5Nb6tMz9JmGtct5qp2KBXG62geVb++szaMwce/qyYq3boyYP27WoWwisf2vWdUGIpzkg0 1GIuKk4EAF2F0T1LAwAA X-Env-Sender: dietmar.hahn@ts.fujitsu.com X-Msg-Ref: server-2.tower-285.messagelabs.com!1576587395!675162!1 X-Originating-IP: [62.60.8.85] X-SYMC-ESS-Client-Auth: outbound-route-from=pass X-StarScan-Received: X-StarScan-Version: 9.44.22; banners=-,-,- X-VirusChecked: Checked Received: (qmail 24937 invoked from network); 17 Dec 2019 12:56:35 -0000 Received: from unknown (HELO mailhost4.uk.fujitsu.com) (62.60.8.85) by server-2.tower-285.messagelabs.com with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 17 Dec 2019 12:56:35 -0000 Received: from sanpedro.mch.fsc.net ([172.17.20.6]) by mailhost4.uk.fujitsu.com (8.14.5/8.14.5) with SMTP id xBHCuYMe013636; Tue, 17 Dec 2019 12:56:34 GMT Received: from amur.mch.fsc.net (unknown [10.172.102.15]) by sanpedro.mch.fsc.net (Postfix) with ESMTP id 1B9F5AB1D3A; Tue, 17 Dec 2019 13:56:26 +0100 (CET) From: Dietmar Hahn To: Andi Kleen Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Al Viro Subject: Re: [PATCH] Fix a panic when core_pattern is set to "| prog..." Date: Tue, 17 Dec 2019 13:56:25 +0100 Message-ID: <7309912.xQAL2Br30t@amur.mch.fsc.net> In-Reply-To: <87r214unfw.fsf@linux.intel.com> References: <2996767.y7E8ffpIOs@amur.mch.fsc.net> <87r214unfw.fsf@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 16. Dezember 2019, 19:37:07 CET schrieb Andi Kleen: > Dietmar Hahn writes: > > > Hi, > > > > if the /proc/sys/kernel/core_pattern is set with a space between '|' and the > > program and later a core file should be written the kernel panics. > > This happens because in format_corename() the first part of cn.corename > > is set to '\0' and later call_usermodehelper_exec() exits because of an > > empty command path but with return 0. But no pipe is created and thus > > cprm.file == NULL. > > This leads in file_start_write() to the panic because of dereferencing > > file_inode(file)->i_mode. > > It would seem better to just skip the spaces and DTRT? This would be the normal case but the mistake happened accidently. And I was really surprised to see the system panic after the segfault of a user program. And it took a little bit time to find the cause ... Dietmar. > Of course doing the error check properly is a good idea anyways. > > -Andi