From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out03.mta.xmission.com ([166.70.13.233]:51303 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932195AbeBSW5W (ORCPT ); Mon, 19 Feb 2018 17:57:22 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Miklos Szeredi Cc: Dongsu Park , lkml , Linux Containers , Alban Crequy , Seth Forshee , Sargun Dhillon , linux-fsdevel , Alexander Viro References: <61a37f0b159dd56825696d8d3beb8eaffdf1f72f.1512041070.git.dongsu@kinvolk.io> Date: Mon, 19 Feb 2018 16:56:56 -0600 In-Reply-To: (Miklos Szeredi's message of "Wed, 14 Feb 2018 13:28:12 +0100") Message-ID: <87mv04mvuv.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [PATCH 07/11] fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Miklos Szeredi writes: > On Fri, Dec 22, 2017 at 3:32 PM, Dongsu Park wrote: >> From: Seth Forshee >> >> The user in control of a super block should be allowed to freeze >> and thaw it. Relax the restrictions on the FIFREEZE and FITHAW >> ioctls to require CAP_SYS_ADMIN in s_user_ns. > > Why is this required for unprivileged fuse? > > Fuse doesn't support freeze, so this seems to make no sense in the > context of this patchset. This isn't required to support fuse. It is a relaxation in permissions so it isn't strictly necessary for anything. Until just recently Seth and I work working through the vfs looking at what we need in general for unprivileged mounts. With fuse as our focus but we were not limiting ourselves to fuse. I have been putting off relaxation of permissions like this because they are not necessary for safety. But in general they do make sense. In practice I think all we need to worry about for fuse is the last 4 patches. Eric