RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Bug 1871784 - Creating a user mapped explicitly with home directory in /tmp breaks the system
Summary: Creating a user mapped explicitly with home directory in /tmp breaks the system
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: libsemanage
Version: 7.8
Hardware: All
OS: Linux
high
high
Target Milestone: rc
: ---
Assignee: Vit Mojzis
QA Contact: BaseOS QE Security Team
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2020-08-24 10:10 UTC by Renaud Métrich
Modified: 2020-08-24 10:56 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2020-08-24 10:56:13 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

Description Renaud Métrich 2020-08-24 10:10:47 UTC 
Description of problem:

Creating a user mapped explicitly with home directory being /tmp breaks the context of /tmp:
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
# useradd -Z unconfined_u -d /tmp test

# matchpathcon /tmp
/tmp	unconfined_u:object_r:user_home_dir_t:s0
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------

This happens even though the default "usepasswd=False" is used in /etc/selinux/semanage.conf:
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
# usepasswd check tells semanage to scan all pass word records for home directories
# and setup the labeling correctly.  If this is turned off, SELinux will label /home 
# correctly only.  You will need to use semanage fcontext command.  
# For example, if you had home dirs in /althome directory you would have to execute
# semanage fcontext -a -e /home /althome
usepasswd=False
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------

With "usepasswd=False", from the comment in the file, the tools are not supposed to change anything that is outside "/home".


Version-Release number of selected component (if applicable):

libsemanage-2.5-14.el7.x86_64


How reproducible:

Always, see above.

Additional info:

This issue is critical when updating Red Hat software such as RHVH: internally RHVH update procedure uses temporary mounts in /tmp/XXX that get all their files relabeled with "user_home_dir_t" due to this bug.

A workaround is to amend "ignoredirs" to specify "/tmp" as well:
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
ignoredirs=/root;/tmp
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
Comment 2 Lukas Vrabec 2020-08-24 10:56:13 UTC 
This issue was not selected to be included in Red Hat Enterprise Linux 7 because it is seen either as low or moderate impact to a small number of use-cases. Current minor release will be in Maintenance Support 2 Phase, which means that qualified Critical and Important Security errata advisories (RHSAs) and Urgent Priority Bug Fix errata advisories (RHBAs) may be released as they become available.

We will now close this issue, but if you believe that it qualifies for the Maintenance Support 2 Phase, please re-open; otherwise, we recommend moving the request to Red Hat Enterprise Linux 8 if applicable.
Note You need to log in before you can comment on or make changes to this bug.