From: ebiederm@xmission.com (Eric W. Biederman)
To: Miklos Szeredi <mszeredi@redhat.com>
Cc: Dongsu Park <dongsu@kinvolk.io>,
lkml <linux-kernel@vger.kernel.org>,
Linux Containers <containers@lists.linux-foundation.org>,
Alban Crequy <alban@kinvolk.io>,
Seth Forshee <seth.forshee@canonical.com>,
Sargun Dhillon <sargun@sargun.me>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH 07/11] fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems
Date: Mon, 19 Feb 2018 16:56:56 -0600 [thread overview]
Message-ID: <87mv04mvuv.fsf@xmission.com> (raw)
In-Reply-To: <CAOssrKeSTY1pAhpmegFWdGh7irNbT4veG5JaYFj8Q1JjMynadw@mail.gmail.com> (Miklos Szeredi's message of "Wed, 14 Feb 2018 13:28:12 +0100")
Miklos Szeredi <mszeredi@redhat.com> writes:
> On Fri, Dec 22, 2017 at 3:32 PM, Dongsu Park <dongsu@kinvolk.io> wrote:
>> From: Seth Forshee <seth.forshee@canonical.com>
>>
>> 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
next prev parent reply other threads:[~2018-02-19 22:57 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-22 14:32 [PATCH v5 00/11] FUSE mounts from non-init user namespaces Dongsu Park
2017-12-22 14:32 ` [PATCH 01/11] block_dev: Support checking inode permissions in lookup_bdev() Dongsu Park
2017-12-22 18:59 ` Coly Li
2017-12-23 12:00 ` Dongsu Park
2017-12-23 3:03 ` Serge E. Hallyn
2017-12-22 14:32 ` [PATCH 02/11] mtd: Check permissions towards mtd block device inode when mounting Dongsu Park
2017-12-22 21:06 ` Richard Weinberger
2017-12-23 12:18 ` Dongsu Park
2017-12-23 12:56 ` Richard Weinberger
2017-12-23 3:05 ` Serge E. Hallyn
2017-12-22 14:32 ` [PATCH 03/11] fs: Allow superblock owner to change ownership of inodes Dongsu Park
2017-12-23 3:17 ` Serge E. Hallyn
2018-01-05 19:24 ` Luis R. Rodriguez
2018-01-09 15:10 ` Dongsu Park
2018-01-09 17:23 ` Luis R. Rodriguez
2018-02-13 13:18 ` Miklos Szeredi
2018-02-16 22:00 ` Eric W. Biederman
2017-12-22 14:32 ` [PATCH 04/11] fs: Don't remove suid for CAP_FSETID for userns root Dongsu Park
2017-12-23 3:26 ` Serge E. Hallyn
2017-12-23 12:38 ` Dongsu Park
2018-02-13 13:37 ` Miklos Szeredi
2017-12-22 14:32 ` [PATCH 05/11] fs: Allow superblock owner to access do_remount_sb() Dongsu Park
2017-12-23 3:30 ` Serge E. Hallyn
2017-12-22 14:32 ` [PATCH 06/11] capabilities: Allow privileged user in s_user_ns to set security.* xattrs Dongsu Park
2017-12-23 3:33 ` Serge E. Hallyn
2017-12-22 14:32 ` [PATCH 07/11] fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems Dongsu Park
2017-12-23 3:39 ` Serge E. Hallyn
2018-02-14 12:28 ` Miklos Szeredi
2018-02-19 22:56 ` Eric W. Biederman [this message]
2017-12-22 14:32 ` [PATCH 08/11] fuse: Support fuse filesystems outside of init_user_ns Dongsu Park
2017-12-23 3:46 ` Serge E. Hallyn
2018-01-17 10:59 ` Alban Crequy
2018-01-17 14:29 ` Seth Forshee
2018-01-17 18:56 ` Alban Crequy
2018-01-17 19:31 ` Seth Forshee
2018-01-18 10:29 ` Alban Crequy
2018-02-12 15:57 ` Miklos Szeredi
2018-02-12 16:35 ` Eric W. Biederman
2018-02-13 10:20 ` Miklos Szeredi
2018-02-16 21:52 ` Eric W. Biederman
2018-02-20 2:12 ` Eric W. Biederman
2017-12-22 14:32 ` [PATCH 09/11] fuse: Restrict allow_other to the superblock's namespace or a descendant Dongsu Park
2017-12-23 3:50 ` Serge E. Hallyn
2018-02-19 23:16 ` Eric W. Biederman
2017-12-22 14:32 ` [PATCH 10/11] fuse: Allow user namespace mounts Dongsu Park
2017-12-23 3:51 ` Serge E. Hallyn
2018-02-14 13:44 ` Miklos Szeredi
2018-02-15 8:46 ` Miklos Szeredi
2017-12-22 14:32 ` [PATCH 11/11] evm: Don't update hmacs in user ns mounts Dongsu Park
2017-12-23 4:03 ` Serge E. Hallyn
2017-12-24 5:12 ` Mimi Zohar
2017-12-24 5:56 ` Mimi Zohar
2017-12-25 7:05 ` [PATCH v5 00/11] FUSE mounts from non-init user namespaces Eric W. Biederman
2018-01-09 15:05 ` Dongsu Park
2018-01-18 14:58 ` Alban Crequy
2018-02-19 23:09 ` Eric W. Biederman
2018-02-13 11:32 ` Miklos Szeredi
2018-02-16 21:53 ` Eric W. Biederman
2018-02-21 20:24 ` [PATCH v6 0/6] fuse: " Eric W. Biederman
2018-02-21 20:29 ` [PATCH v6 1/5] fuse: Remove the buggy retranslation of pids in fuse_dev_do_read Eric W. Biederman
2018-02-22 10:13 ` Miklos Szeredi
2018-02-22 19:04 ` Eric W. Biederman
2018-02-21 20:29 ` [PATCH v6 2/5] fuse: Fail all requests with invalid uids or gids Eric W. Biederman
2018-02-22 10:26 ` Miklos Szeredi
2018-02-22 18:15 ` Eric W. Biederman
2018-02-21 20:29 ` [PATCH v6 3/5] fuse: Support fuse filesystems outside of init_user_ns Eric W. Biederman
2018-02-21 20:29 ` [PATCH v6 4/5] fuse: Ensure posix acls are translated " Eric W. Biederman
2018-02-22 11:40 ` Miklos Szeredi
2018-02-22 19:18 ` Eric W. Biederman
2018-02-22 22:50 ` Eric W. Biederman
2018-02-26 7:47 ` Miklos Szeredi
2018-02-26 16:35 ` Eric W. Biederman
2018-02-26 21:51 ` Eric W. Biederman
2018-02-21 20:29 ` [PATCH v6 5/5] fuse: Restrict allow_other to the superblock's namespace or a descendant Eric W. Biederman
2018-02-26 23:52 ` [PATCH v7 0/7] fuse: mounts from non-init user namespaces Eric W. Biederman
2018-02-26 23:52 ` [PATCH v7 1/7] fuse: Remove the buggy retranslation of pids in fuse_dev_do_read Eric W. Biederman
2018-02-26 23:52 ` [PATCH v7 2/7] fuse: Fail all requests with invalid uids or gids Eric W. Biederman
2018-02-26 23:52 ` [PATCH v7 3/7] fs/posix_acl: Document that get_acl respects ACL_DONT_CACHE Eric W. Biederman
2018-02-27 1:13 ` Linus Torvalds
2018-02-27 2:53 ` Eric W. Biederman
2018-02-27 3:14 ` Eric W. Biederman
2018-02-27 3:41 ` Linus Torvalds
2018-03-02 19:53 ` [RFC][PATCH] fs/posix_acl: Update the comments and support lightweight cache skipping Eric W. Biederman
2018-02-27 3:36 ` [PATCH v7 3/7] fs/posix_acl: Document that get_acl respects ACL_DONT_CACHE Linus Torvalds
2018-02-26 23:52 ` [PATCH v7 4/7] fuse: Cache a NULL acl when FUSE_GETXATTR returns -ENOSYS Eric W. Biederman
2018-02-26 23:53 ` [PATCH v7 5/7] fuse: Simplfiy the posix acl handling logic Eric W. Biederman
2018-02-27 9:00 ` Miklos Szeredi
2018-03-02 21:49 ` Eric W. Biederman
2018-02-26 23:53 ` [PATCH v7 6/7] fuse: Support fuse filesystems outside of init_user_ns Eric W. Biederman
2018-02-26 23:53 ` [PATCH v7 7/7] fuse: Restrict allow_other to the superblock's namespace or a descendant Eric W. Biederman
2018-03-02 21:58 ` [PATCH v8 0/6] fuse: mounts from non-init user namespaces Eric W. Biederman
2018-03-02 21:59 ` [PATCH v8 1/6] fs/posix_acl: Update the comments and support lightweight cache skipping Eric W. Biederman
2018-03-05 9:53 ` Miklos Szeredi
2018-03-05 13:53 ` Eric W. Biederman
2018-03-02 21:59 ` [PATCH v8 2/6] fuse: Simplfiy the posix acl handling logic Eric W. Biederman
2018-03-02 21:59 ` [PATCH v8 3/6] fuse: Remove the buggy retranslation of pids in fuse_dev_do_read Eric W. Biederman
2018-03-02 21:59 ` [PATCH v8 4/6] fuse: Fail all requests with invalid uids or gids Eric W. Biederman
2018-03-02 21:59 ` [PATCH v8 5/6] fuse: Support fuse filesystems outside of init_user_ns Eric W. Biederman
2018-03-02 21:59 ` [PATCH v8 6/6] fuse: Restrict allow_other to the superblock's namespace or a descendant Eric W. Biederman
2018-03-08 21:23 ` [PATCH v9 0/4] fuse: mounts from non-init user namespaces Eric W. Biederman
2018-03-08 21:24 ` [PATCH v9 1/4] fuse: Remove the buggy retranslation of pids in fuse_dev_do_read Eric W. Biederman
2018-03-08 21:24 ` [PATCH v9 2/4] fuse: Fail all requests with invalid uids or gids Eric W. Biederman
2018-03-08 21:24 ` [PATCH v9 3/4] fuse: Support fuse filesystems outside of init_user_ns Eric W. Biederman
2018-03-08 21:24 ` [PATCH v9 4/4] fuse: Restrict allow_other to the superblock's namespace or a descendant Eric W. Biederman
2018-03-20 16:25 ` [PATCH v9 0/4] fuse: mounts from non-init user namespaces Miklos Szeredi
2018-03-20 18:27 ` Eric W. Biederman
2018-03-21 8:38 ` Miklos Szeredi
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