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=-0.6 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=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 CF680C2D0DB for ; Mon, 27 Jan 2020 20:33:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9887A24679 for ; Mon, 27 Jan 2020 20:33:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=fastmail.com header.i=@fastmail.com header.b="txcCO4ws"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="paURXrYu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725955AbgA0Udi (ORCPT ); Mon, 27 Jan 2020 15:33:38 -0500 Received: from wout4-smtp.messagingengine.com ([64.147.123.20]:54031 "EHLO wout4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725944AbgA0Udh (ORCPT ); Mon, 27 Jan 2020 15:33:37 -0500 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id F10B6638 for ; Mon, 27 Jan 2020 15:33:36 -0500 (EST) Received: from imap4 ([10.202.2.54]) by compute3.internal (MEProxy); Mon, 27 Jan 2020 15:33:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastmail.com; h= mime-version:message-id:date:from:to:subject:content-type; s= fm2; bh=zg5ssK407JPg1RZMfOec4RxYfdcQGWZdVLCugGNiFFk=; b=txcCO4ws 5DL65ZIABDdY2mMQNZ9TnLKjQymITjLaczZHQt0JSmzsa8zS0EPSbYTZl0/Kf6Ux WBwWt17A72etn8lvAeOZZweu/bkYnvhrkcG+ds+cyYi/VGuC+Eh9s3i8seb5HswI CYUokkZfEYLpa9wB4p44my+W+gaevAzAZeYkClO5bunQmWE5EIkaPadlBPO8jeTG bh4wxL23H7h0mUabUySMCiaeoR+BVNMwuvBlBmCeMG2ZHE1Cac8LGfAxCg2uB+BR w3dA66GmVqKO/+DSSW1AyS0Ic+Ud3j+cTNP3PInhP2ovKGiTWEfVtbv8mIPMCx5X Cc6kcghHAakSfQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:date:from:message-id :mime-version:subject:to:x-me-proxy:x-me-proxy:x-me-sender :x-me-sender:x-sasl-enc; s=fm1; bh=zg5ssK407JPg1RZMfOec4RxYfdcQG WZdVLCugGNiFFk=; b=paURXrYuxaM/obwpK4J8CFuRfyr4pfgSVpJsi5VMF9mTL N1eYtYUqHsYfpfmHSMBkChsiuL7XH4M4KI3Ds/ZnGiINgTovV/ZEEqje087x9TbI +uJLJQoJ0zt/p5w3AAoBlAY30FJP6ROgY11gYEkA2GTGXG9C3i/eL1k8SGGZqXPh UCCsmTPZ0WXFHUgYTCxL8mnwXn1KpqcdIZpwmCZIJQIY1kPE4jOB29s3/gO0UrTa DWdQglmZxzmAPXlN1zP8KdRsOaejl9D91YPSrEtjJMBrYsUsnXSXLtbeajC7cB5k 7uBu3RMMa5y50LnukCqt3BfsRqi4VQZntz0RZhOBw== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrfedvgddufeeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefofgggkfffhffvufgtsehttdertd erredtnecuhfhrohhmpedftehlvgigrghnuggvrhcukfhvrghnohhvfdcuoegrmhhivhgr nhhovhesfhgrshhtmhgrihhlrdgtohhmqeenucevlhhushhtvghrufhiiigvpedtnecurf grrhgrmhepmhgrihhlfhhrohhmpegrmhhivhgrnhhovhesfhgrshhtmhgrihhlrdgtohhm X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id 784333C00A1; Mon, 27 Jan 2020 15:33:36 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.1.7-781-gfc16016-fmstable-20200127v1 Mime-Version: 1.0 Message-Id: <9e7ccbf8-e640-49b1-8e9c-ffa330b0feef@www.fastmail.com> Date: Mon, 27 Jan 2020 12:34:05 -0800 From: "Alexander Ivanov" To: linux-security-module@vger.kernel.org Subject: Denying access from sb_umount issue Content-Type: text/plain Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: The lsm module implementes sb_umount() hook to disable lazy umounts. When access is denied, all consecutive umounts fail. It looks like mount reference count is messed up when sb_umount() return -EPERM. Is it possible that umount syscall assumes do_umount() touches those references and it calls dput(path.dentry); mntput_no_expire(mnt); regardless of what do_mount() returns? Thanks, --Alex