From mboxrd@z Thu Jan  1 00:00:00 1970
From: Lubomir Rintel <lkundrak@v3.sk>
Subject: 4.2: Can't mount sysfs in a mount ns & user ns
Date: Thu, 13 Aug 2015 09:53:16 +0200
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Cc: "Eric W. Biederman" <ebiederm@xmission.com>
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Hi,

4.0.6-300.fc22.x86_64:
[lkundrak@fedora22-1 ~]$ unshare -r --mount --net
[root@fedora22-1 ~]# mount --make-slave /sys
[root@fedora22-1 ~]# mount -t sysfs sysfs /sys
[root@fedora22-1 ~]# 

4.2.0-0.rc6.git0.1.fc24.x86_64:
[lkundrak@fedora23-1 ~]$ unshare -r --mount --net
[root@fedora23-1 ~]# mount --make-slave /sys
[root@fedora23-1 ~]# mount -t sysfs sysfs /sys
mount: permission denied
[root@fedora23-1 ~]#

we use this in NetworkManager test suite, to ensure the devices we see
via GUdev are the same as we see via rtnetlink.

I'm wondering if this is a bug or an intended change?

Thanks,
Lubo