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ZFS on Linux - Slackware 14.1 and setuid problems

This is probably a niche topic but perhaps someone has run into this strangeness. On real (not virtualized) hardware, I have two identical instances of Slackware64-current at my disposal.

The primary system is good old ext4 and my playpen system is ZFS-0.6.2. I don't spend much time in the latter experimental system but tonight I encountered something odd. As a regular user, I executed this command:

sudo ls /root

Here's the result:

Code:

sudo: unable to stat /etc/sudoers: Permission denied

sudo: no valid sudoers sources found, quitting

sudo: unable to initialize policy plugin

And running strace, more detail emerges:

Code:

sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the 'nosuid' option set or an NFS file system without root privileges?

Yet these things show no indication of suid being disabled:

Code:

zducky/slack on / type zfs (rw,relatime,xattr)

zducky/slack setuid  on  default

I think a handful of forum participants are using ZFS on Linux and any troubleshooting tips would be appreciated.

What are the permissions on /etc/sudoers? Should be 440.
What are the permissions on `which sudo`? Should be 4755.

Quote:

Originally Posted by AlucardZero (Post 5065906)

What are the permissions on /etc/sudoers? Should be 440.
What are the permissions on `which sudo`? Should be 4755.

Code:

-r--r----- 1 root root  3012 Nov  9 13:50 /etc/sudoers

-rwsr-xr-x 1 root root 134128 Nov  8 12:11 /usr/bin/sudo

The playpen experimental system using ZFS is a replica (via rsync -xHDa) of the main system, so all perms and ownership are preserved. Another oddity, perhaps related, is that using ncsd on the ZFS-based system returns nothing for all of the service definitions it maintains. On those occasions when I boot into the ZFS Slackware system, I just disable that glibc-provided name service caching daemon.