Our automated TC for snapper passes on x86_64 VM 1MT-RHEL-7.5-20180315.0 if the latest selinux-policy (3.13.1-192.el7_5.1) installed. Could you re-run your snapper tests and let us know, what are their results.

The same SELinux denial as mentioned in comment#7 we already saw in BZ#1063150.

Our TC found out that following rules are missing:

allow snapperd_t kernel_t : process { setsched };
allow snapperd_t fs_t : filesystem { mount };

The reason for switching this bug to ASSIGNED is that both rules should be present, but they are not. BZ#1063150 is closed as current release, therefore the rules should be present.

Jakub, 

Following line: 

allow snapperd_t kernel_t : process { setsched };

Is allowing snapperd to set priority for kernel threads. Is to okay? Snapperd is manipulating with kernel threads prio? 

THanks,
Lukas.

Lukas,
I lack the knowledge to answer this properly, this is more a question for Ondrej.
Jakub

Snapperd is lowering priority of background tasks (threads) performing snapshot comparison. Both process priority and i/o priority are set (lowered).

setpriority()
syscall(SYS_ioprio_set,...)

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:1059