RE: [PATCH 2/4] fs: define a firmware security filesystem named fwsecurityfs

[David Laight <David.Laight@ACULAB.COM>]

From: James Bottomley
> Sent: 21 November 2022 14:03
...
> > Then how does the networking code handle the namespace stuff in
> > sysfs?
> > That seems to work today, or am I missing something?
> 
> have you actually tried?
> 
> jejb@lingrow:~> sudo unshare --net bash
> lingrow:/home/jejb # ls /sys/class/net/
> lo  tun0  tun10  wlan0
> lingrow:/home/jejb # ip link show
> 1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT group
> default qlen 1000
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> 
> So, as you see, I've entered a network namespace and ip link shows me
> the only interface I can see in that namespace (a down loopback) but
> sysfs shows me every interface on the system outside the namespace.

You have to remount /sys to get the restricted copy.
eg by running 'ip netns exec namespace command'.

	David

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