Bug 258481

Summary:	Jail information leak via zfs kstats
Product:	Base System	Reporter:	Alan Somers <asomers>
Component:	kern	Assignee:	Allan Jude <allanjude>
Status:	Closed FIXED
Severity:	Affects Many People	CC:	admin, allanjude, chris, dvl, emaste, grahamperrin, pi
Priority:	---
Version:	CURRENT
Hardware:	Any
OS:	Any

Description Alan Somers freebsd_committer

2021-09-13 16:52:45 UTC

A jailed user can determine the names and throughput of ZFS datasets that aren't accessible in the jail, by querying the kstat.zfs.zroot.dataset tree.  For example:

[asomers@universe14a ~]$ sysctl kstat.zfs | grep dataset_name
kstat.zfs.zroot.dataset.objset-0x81.dataset_name: zroot/var/tmp
kstat.zfs.zroot.dataset.objset-0x7a.dataset_name: zroot/var/spool
kstat.zfs.zroot.dataset.objset-0x73.dataset_name: zroot/var/run
kstat.zfs.zroot.dataset.objset-0x6c.dataset_name: zroot/var/log
kstat.zfs.zroot.dataset.objset-0x65.dataset_name: zroot/var/empty
kstat.zfs.zroot.dataset.objset-0x5e.dataset_name: zroot/var/db
kstat.zfs.zroot.dataset.objset-0x8f.dataset_name: zroot/var/cache/pkg
kstat.zfs.zroot.dataset.objset-0x88.dataset_name: zroot/var/cache
kstat.zfs.zroot.dataset.objset-0x57.dataset_name: zroot/var
kstat.zfs.zroot.dataset.objset-0x29.dataset_name: zroot/usr/src
kstat.zfs.zroot.dataset.objset-0x45.dataset_name: zroot/usr/obj
kstat.zfs.zroot.dataset.objset-0x50.dataset_name: zroot/usr/local
kstat.zfs.zroot.dataset.objset-0x3b.dataset_name: zroot/usr
kstat.zfs.zroot.dataset.objset-0x34.dataset_name: zroot/tmp
kstat.zfs.zroot.dataset.objset-0x39b.dataset_name: zroot/j/jails/universe14a/scratch
kstat.zfs.zroot.dataset.objset-0x596.dataset_name: zroot/j/jails/universe14a/home
kstat.zfs.zroot.dataset.objset-0xad.dataset_name: zroot/j/jails/universe14a
kstat.zfs.zroot.dataset.objset-0x1b0.dataset_name: zroot/j/jails/universe13a/scratch
kstat.zfs.zroot.dataset.objset-0x1aa.dataset_name: zroot/j/jails/universe13a/home
kstat.zfs.zroot.dataset.objset-0x1a4.dataset_name: zroot/j/jails/universe13a
kstat.zfs.zroot.dataset.objset-0x1cd.dataset_name: zroot/j/jails/universe12a/scratch
kstat.zfs.zroot.dataset.objset-0x1d3.dataset_name: zroot/j/jails/universe12a/home
kstat.zfs.zroot.dataset.objset-0x11e.dataset_name: zroot/j/jails/universe12a
kstat.zfs.zroot.dataset.objset-0xde.dataset_name: zroot/j/jails/universe11a/scratch
kstat.zfs.zroot.dataset.objset-0xd2.dataset_name: zroot/j/jails/universe11a/home
kstat.zfs.zroot.dataset.objset-0x98.dataset_name: zroot/j/jails/universe11a
kstat.zfs.zroot.dataset.objset-0x59.dataset_name: zroot/j/jails
kstat.zfs.zroot.dataset.objset-0x3f.dataset_name: zroot/j
kstat.zfs.zroot.dataset.objset-0x192ec.dataset_name: zroot/git
kstat.zfs.zroot.dataset.objset-0x2d.dataset_name: zroot/home
kstat.zfs.zroot.dataset.objset-0x15.dataset_name: zroot

Comment 1 Allan Jude freebsd_committer

2022-09-20 13:34:48 UTC

I am looking into this

Comment 2 Allan Jude freebsd_committer

2022-12-03 02:47:50 UTC

upstream pull request: https://github.com/openzfs/zfs/pull/14254

Comment 3 Allan Jude freebsd_committer

2023-02-04 19:07:31 UTC

This was merged into stable/13 on 2023-01-26 and will be included in 13.2-RELEASE