From patchwork Wed Apr 22 14:54:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 220768 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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 2755AC55185 for ; Wed, 22 Apr 2020 14:55:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0EB392076E for ; Wed, 22 Apr 2020 14:55:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728094AbgDVOzb (ORCPT ); Wed, 22 Apr 2020 10:55:31 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49646 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727920AbgDVOzT (ORCPT ); Wed, 22 Apr 2020 10:55:19 -0400 Received: from ip5f5af183.dynamic.kabel-deutschland.de ([95.90.241.131] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jRGmR-0006CM-Oh; Wed, 22 Apr 2020 14:55:15 +0000 From: Christian Brauner To: Jens Axboe , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: Jonathan Corbet , Serge Hallyn , "Rafael J. Wysocki" , Tejun Heo , "David S. Miller" , Christian Brauner , Saravana Kannan , Jan Kara , David Howells , Seth Forshee , David Rheinsberg , Tom Gundersen , Christian Kellner , Dmitry Vyukov , =?utf-8?q?St=C3=A9phane_Gr?= =?utf-8?q?aber?= , linux-doc@vger.kernel.org, netdev@vger.kernel.org, Steve Barber , Dylan Reid , Filipe Brandenburger , Kees Cook , Benjamin Elder , Akihiro Suda Subject: [PATCH v2 7/7] loopfs: only show devices in their correct instance Date: Wed, 22 Apr 2020 16:54:37 +0200 Message-Id: <20200422145437.176057-8-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200422145437.176057-1-christian.brauner@ubuntu.com> References: <20200422145437.176057-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since loopfs devices belong to a loopfs instance they have no business polluting the host's devtmpfs mount and should not propagate out of the namespace they belong to. Cc: Jens Axboe Cc: Greg Kroah-Hartman Signed-off-by: Christian Brauner --- /* v2 */ unchanged --- drivers/base/devtmpfs.c | 4 ++-- drivers/block/loop.c | 4 +++- include/linux/device.h | 3 +++ 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index c9017e0584c0..77371ceb88fa 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -111,7 +111,7 @@ int devtmpfs_create_node(struct device *dev) const char *tmp = NULL; struct req req; - if (!thread) + if (!thread || dev->no_devnode) return 0; req.mode = 0; @@ -138,7 +138,7 @@ int devtmpfs_delete_node(struct device *dev) const char *tmp = NULL; struct req req; - if (!thread) + if (!thread || dev->no_devnode) return 0; req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp); diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 2dc53bad4b48..5548151b9f11 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2213,8 +2213,10 @@ static int loop_add(struct loop_device **l, int i, struct inode *inode) disk->queue = lo->lo_queue; sprintf(disk->disk_name, "loop%d", i); #ifdef CONFIG_BLK_DEV_LOOPFS - if (loopfs_i_sb(inode)) + if (loopfs_i_sb(inode)) { disk->user_ns = loopfs_i_sb(inode)->s_user_ns; + disk_to_dev(disk)->no_devnode = true; + } #endif add_disk(disk); diff --git a/include/linux/device.h b/include/linux/device.h index ac8e37cd716a..c69ef1c5a0ef 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -523,6 +523,8 @@ struct dev_links_info { * sync_state() callback. * @dma_coherent: this particular device is dma coherent, even if the * architecture supports non-coherent devices. + * @no_devnode: whether device nodes associated with this device are kept out + * of devtmpfs (e.g. due to separate filesystem) * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -622,6 +624,7 @@ struct device { defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) bool dma_coherent:1; #endif + bool no_devnode:1; }; static inline struct device *kobj_to_dev(struct kobject *kobj)