From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: "Christian Brauner" <christian.brauner@ubuntu.com>,
"Stéphane Graber" <stgraber@ubuntu.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Aleksa Sarai" <cyphar@cyphar.com>,
"Jann Horn" <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>,
Jonathan Corbet <corbet@lwn.net>,
linux-kernel@vger.kernel.org,
containers@lists.linux-foundation.org, smbarber@chromium.org,
Seth Forshee <seth.forshee@canonical.com>,
linux-security-module@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Alexey Dobriyan <adobriyan@gmail.com>
Subject: Re: [PATCH v2 00/28] user_namespace: introduce fsid mappings
Date: Mon, 17 Feb 2020 13:06:08 -0800 [thread overview]
Message-ID: <1581973568.24289.6.camel@HansenPartnership.com> (raw)
In-Reply-To: <20200214183554.1133805-1-christian.brauner@ubuntu.com>
On Fri, 2020-02-14 at 19:35 +0100, Christian Brauner wrote:
[...]
> People not as familiar with user namespaces might not be aware that
> fsid mappings already exist. Right now, fsid mappings are always
> identical to id mappings. Specifically, the kernel will lookup fsuids
> in the uid mappings and fsgids in the gid mappings of the relevant
> user namespace.
This isn't actually entirely true: today we have the superblock user
namespace, which can be used for fsid remapping on filesystems that
support it (currently f2fs and fuse). Since this is a single shift,
how is it going to play with s_user_ns? Do you have to understand the
superblock mapping to use this shift, or are we simply using this to
replace s_user_ns?
James
next prev parent reply other threads:[~2020-02-17 21:06 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-14 18:35 [PATCH v2 00/28] user_namespace: introduce fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 01/28] user_namespace: introduce fsid mappings infrastructure Christian Brauner
2020-02-14 18:35 ` [PATCH v2 02/28] proc: add /proc/<pid>/fsuid_map Christian Brauner
2020-02-14 18:35 ` [PATCH v2 03/28] proc: add /proc/<pid>/fsgid_map Christian Brauner
2020-02-14 18:35 ` [PATCH v2 04/28] fsuidgid: add fsid mapping helpers Christian Brauner
2020-02-14 19:11 ` Jann Horn
2020-02-16 16:55 ` Christian Brauner
2020-02-14 18:35 ` [PATCH v2 05/28] proc: task_state(): use from_kfs{g,u}id_munged Christian Brauner
2020-02-14 18:35 ` [PATCH v2 06/28] cred: add kfs{g,u}id Christian Brauner
2020-02-14 18:35 ` [PATCH v2 07/28] sys: __sys_setfsuid(): handle fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 08/28] sys: __sys_setfsgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 09/28] sys:__sys_setuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 10/28] sys:__sys_setgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 11/28] sys:__sys_setreuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 12/28] sys:__sys_setregid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 13/28] sys:__sys_setresuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 14/28] sys:__sys_setresgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 15/28] fs: add is_userns_visible() helper Christian Brauner
2020-02-14 18:35 ` [PATCH v2 16/28] namei: may_{o_}create(): handle fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 17/28] inode: inode_owner_or_capable(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 18/28] capability: privileged_wrt_inode_uidgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 19/28] stat: " Christian Brauner
2020-02-14 19:03 ` Tycho Andersen
2020-02-16 14:12 ` Christian Brauner
2020-02-14 18:35 ` [PATCH v2 20/28] open: " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 21/28] posix_acl: " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 22/28] attr: notify_change(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 23/28] commoncap: cap_bprm_set_creds(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 24/28] commoncap: cap_task_fix_setuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 25/28] commoncap: handle fsid mappings with vfs caps Christian Brauner
2020-02-14 18:35 ` [PATCH v2 26/28] exec: bprm_fill_uid(): handle fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 27/28] ptrace: adapt ptrace_may_access() to always uses unmapped fsids Christian Brauner
2020-02-14 18:35 ` [PATCH v2 28/28] devpts: handle fsid mappings Christian Brauner
2020-02-16 15:55 ` [PATCH v2 00/28] user_namespace: introduce " Florian Weimer
2020-02-16 16:40 ` Christian Brauner
2020-02-17 21:06 ` James Bottomley [this message]
2020-02-17 21:20 ` Christian Brauner
2020-02-17 22:35 ` James Bottomley
2020-02-17 23:05 ` Christian Brauner
2020-02-17 21:11 ` James Bottomley
[not found] ` <CA+enf=vwd-dxzve87t7Mw1Z35RZqdLzVaKq=fZ4EGOpnES0f5w@mail.gmail.com>
2020-02-17 22:02 ` Stéphane Graber
2020-02-17 23:03 ` James Bottomley
2020-02-17 23:11 ` Stéphane Graber
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