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=-3.8 required=3.0 tests=BAYES_00, 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 0242BC63798 for ; Mon, 23 Nov 2020 15:52:17 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5346F208FE for ; Mon, 23 Nov 2020 15:52:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5346F208FE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=tycho.pizza Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=linux-audit-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-595-d4RepujRP1qQ54dKChFLuw-1; Mon, 23 Nov 2020 10:52:12 -0500 X-MC-Unique: d4RepujRP1qQ54dKChFLuw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C4A08805BFB; Mon, 23 Nov 2020 15:51:31 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3637B620DE; Mon, 23 Nov 2020 15:51:31 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 97860180954D; Mon, 23 Nov 2020 15:51:30 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 0ANFldXO014691 for ; Mon, 23 Nov 2020 10:47:39 -0500 Received: by smtp.corp.redhat.com (Postfix) id 25D342166B2B; Mon, 23 Nov 2020 15:47:39 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast03.extmail.prod.ext.rdu2.redhat.com [10.11.55.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 20E5A2166B27 for ; Mon, 23 Nov 2020 15:47:36 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0A27D811E85 for ; Mon, 23 Nov 2020 15:47:36 +0000 (UTC) Received: from new4-smtp.messagingengine.com (new4-smtp.messagingengine.com [66.111.4.230]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-172-vzsgBE0QOqO-XSQoLhE3vA-1; Mon, 23 Nov 2020 10:47:31 -0500 X-MC-Unique: vzsgBE0QOqO-XSQoLhE3vA-1 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailnew.nyi.internal (Postfix) with ESMTP id D00855803A4; Mon, 23 Nov 2020 10:47:30 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Mon, 23 Nov 2020 10:47:30 -0500 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrudegiedgkedvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefvhigthhho ucetnhguvghrshgvnhcuoehthigthhhosehthigthhhordhpihiiiigrqeenucggtffrrg htthgvrhhnpeegkeefjeegkedtjefgfeduleekueetjeeghffhuefgffefleehgeeifedv gfethfenucfkphepuddvkedruddtjedrvdeguddrudejgeenucevlhhushhtvghrufhiii gvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehthigthhhosehthigthhhordhpihii iigr X-ME-Proxy: Received: from cisco (unknown [128.107.241.174]) by mail.messagingengine.com (Postfix) with ESMTPA id C041D3064ABE; Mon, 23 Nov 2020 10:47:21 -0500 (EST) Date: Mon, 23 Nov 2020 10:47:19 -0500 From: Tycho Andersen To: Christian Brauner Subject: Re: [PATCH v2 07/39] mount: attach mappings to mounts Message-ID: <20201123154719.GD4025434@cisco> References: <20201115103718.298186-1-christian.brauner@ubuntu.com> <20201115103718.298186-8-christian.brauner@ubuntu.com> MIME-Version: 1.0 In-Reply-To: <20201115103718.298186-8-christian.brauner@ubuntu.com> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-loop: linux-audit@redhat.com X-Mailman-Approved-At: Mon, 23 Nov 2020 10:51:29 -0500 Cc: Andy Lutomirski , Mimi Zohar , James Bottomley , Andreas Dilger , Christoph Hellwig , Jonathan Corbet , smbarber@chromium.org, Christoph Hellwig , linux-ext4@vger.kernel.org, Mrunal Patel , Arnd Bergmann , Jann Horn , selinux@vger.kernel.org, Josh Triplett , Seth Forshee , Aleksa Sarai , Alexander Viro , Lennart Poettering , OGAWA Hirofumi , Geoffrey Thomas , David Howells , John Johansen , Theodore Tso , Dmitry Kasatkin , containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-audit@redhat.com, "Eric W. Biederman" , linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, Alban Crequy , linux-integrity@vger.kernel.org, Todd Kjos X-BeenThere: linux-audit@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Linux Audit Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=linux-audit-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Sun, Nov 15, 2020 at 11:36:46AM +0100, Christian Brauner wrote: > +static inline struct user_namespace *mnt_user_ns(const struct vfsmount *mnt) > +{ > + return mnt->mnt_user_ns; > +} I think you might want a READ_ONCE() here. Right now it seems ok, since the mnt_user_ns can't change, but if we ever allow it to change (and I see you have a idmapped_mounts_wip_v2_allow_to_change_idmapping branch on your public tree :D), the pattern of, user_ns = mnt_user_ns(path->mnt); if (mnt_idmapped(path->mnt)) { uid = kuid_from_mnt(user_ns, uid); gid = kgid_from_mnt(user_ns, gid); } could race. Tycho -- Linux-audit mailing list Linux-audit@redhat.com https://www.redhat.com/mailman/listinfo/linux-audit