From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out01.mta.xmission.com ([166.70.13.231]:47865 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934671AbeEWXXH (ORCPT ); Wed, 23 May 2018 19:23:07 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Linux Containers Cc: , Seth Forshee , "Serge E. Hallyn" , Christian Brauner , Date: Wed, 23 May 2018 18:22:56 -0500 Message-ID: <87o9h6554f.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [REVIEW][PATCH 0/6] Wrapping up the vfs support for unprivileged mounts Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Very slowly the work has been progressing to ensure the vfs has the necessary support for mounting filesystems without privilege. This patchset contains one more core piece of that work, ensuring a few more operations that would write back an inode and confuse an exisiting filesystem are denied. The rest of the changes actually enable userns root to do things with filesystems that the userns root has mounted. Most of these have been waiting in the wings a long time, held back because I wanted the core of the patchset to be solid before I started allowing additional behavor. It is definitely time for these changes so the effect of s_user_ns becomes less theoretical. The change to allow mknod is new, but consistent with everything else and harmless as device nodes on filesystems mounted without privilege are ignored. Unless problems show up in the during review I plan to merge these changes. These changes are also available at: git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git userns-test Eric W. Biederman (5): vfs: Don't allow changing the link count of an inode with an invalid uid or gid vfs: Allow userns root to call mknod on owned filesystems. fs: Allow superblock owner to replace invalid owners of inodes fs: Allow superblock owner to access do_remount_sb() capabilities: Allow privileged user in s_user_ns to set security.* xattrs Seth Forshee (1): fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems fs/attr.c | 36 ++++++++++++++++++++++++++++-------- fs/ioctl.c | 4 ++-- fs/namei.c | 16 ++++++++++++---- fs/namespace.c | 4 ++-- security/commoncap.c | 8 ++++++-- 5 files changed, 50 insertions(+), 18 deletions(-) Eric