Hands-on Lab·Red Hat Certified System Administrator
Default Permissions and umask
One objective. The arithmetic is simple once you know files start from 666 and directories from 777 - and that the umask *removes* bits rather than granting them, which is why a new file is never executable however permissive the umask.
Security and SELinux Guide 54 of 67 Beginner
- OSRHEL 10.0 (Coughlan)
- Kernel6.12.0-55.9.1.el10_0
- dnf4.20.0
- Flatpak1.16.0
- TimeAbout 10 min
- Reviewed23 August 2026
Written against the versions above. Two places set it and they are not interchangeable. **`/etc/login.defs UMASK`** is applied by `pam_umask` at login, for any session. **`/etc/profile` and `/etc/bashrc`** set it for shells. RHEL 10's default is `022` for root and `002` for ordinary users, because of the user private group scheme.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| RHCSA-A01 | 192.168.0.31 | RHEL 10.0 (Coughlan) | Practice node (graded) - spare /dev/sda | 2 Core | 4 GB | 50 GB + 15 GB |
Before you start
- A shell.
- The session writes and removes
/tmp/umtest.
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What it does
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Changing it
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Making it stick