[lxc-users] "lxc list" on Linux 4.18: cannot perform readlinkat() on the mount namespace file descriptor of the init process: Permission denied

[Tomasz Chmielewski]

# lxc list
cannot perform readlinkat() on the mount namespace file descriptor of
the init process: Permission denied

# dmesg -c
[ 1554.529049] audit: type=1400 audit(1534333565.580:49):
apparmor="DENIED" operation="ptrace"
profile="/snap/core/5145/usr/lib/snapd/snap-confine" pid=2636
comm="snap-confine" requested_mask="read" denied_mask="read"
peer="unconfined"


This is after upgrading the kernel to:

# uname -a
Linux lxd05 4.18.0-041800-generic #201808122131 SMP Sun Aug 12 21:33:20
UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


# snap list
Name Version Rev Tracking Publisher Notes
core 16-2.34.3 5145 stable canonical core
lxd 3.3 8011 stable canonical -


# cat /etc/issue
Ubuntu 18.04.1 LTS \n \l



Expected?



Tomasz Chmielewski
https://lxadm.com

[Christian Brauner]

Post by Tomasz Chmielewski
# lxc list
cannot perform readlinkat() on the mount namespace file descriptor of the
init process: Permission denied

Where is this error coming from? It's not from LX{C,D}
What does lxc info show?

Post by Tomasz Chmielewski
# dmesg -c
[ 1554.529049] audit: type=1400 audit(1534333565.580:49): apparmor="DENIED"
operation="ptrace" profile="/snap/core/5145/usr/lib/snapd/snap-confine"
pid=2636 comm="snap-confine" requested_mask="read" denied_mask="read"
peer="unconfined"
# uname -a
Linux lxd05 4.18.0-041800-generic #201808122131 SMP Sun Aug 12 21:33:20 UTC
2018 x86_64 x86_64 x86_64 GNU/Linux
# snap list
Name Version Rev Tracking Publisher Notes
core 16-2.34.3 5145 stable canonical core
lxd 3.3 8011 stable canonical -
# cat /etc/issue
Ubuntu 18.04.1 LTS \n \l
Expected?
Tomasz Chmielewski
https://lxadm.com
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[Tomasz Chmielewski]

Post by Christian Brauner

Post by Tomasz Chmielewski
# lxc list
cannot perform readlinkat() on the mount namespace file descriptor of the
init process: Permission denied

Where is this error coming from? It's not from LX{C,D}
What does lxc info show?

It looks like some apparmor / snap issue:

https://bugs.launchpad.net/snapd/+bug/1786889


Tomasz Chmielewski
https://lxadm.com