Bug 1919122
| Summary: | Permission denied+AVC seen when executing "sudo authconfig" as a confined user (staff_u or sysadm_u) | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Renaud Métrich <rmetrich> |
| Component: | selinux-policy | Assignee: | Zdenek Pytela <zpytela> |
| Status: | CLOSED ERRATA | QA Contact: | Amith <apeetham> |
| Severity: | medium | Docs Contact: | |
| Priority: | high | ||
| Version: | 8.3 | CC: | lvrabec, miturria, mmalik, plautrba, ssekidde |
| Target Milestone: | rc | Keywords: | Triaged |
| Target Release: | 8.6 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | selinux-policy-3.14.3-86.el8 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2022-05-10 15:14:56 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 1778780 | ||
Thank you. Switching to selinux-policy. Interestingly, if the sysadm_u user can change to root via sudo -i, they *can* run the authconfig command while running a root shell: > sudo authconfig --test [sudo] password for user: sudo: unable to execute /sbin/authconfig: Permission denied > sudo -i > whoami root > id -Z sysadm_u:sysadm_r:sysadm_t:s0 > authconfig --test Running authconfig compatibility tool. [...] Why would that be the case? Will be resolved by labeling /usr/lib/python3.6/site-packages/authselect/authcompat.py but in RHEL 8 only as there is no authselect-compat in current releases. 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 (selinux-policy bug fix and enhancement update), 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-2022:1995 |
Description of problem: Executing "sudo authconfig" as a confined user ends up having a Permission denied + AVC: -------- 8< ---------------- 8< ---------------- 8< ---------------- 8< -------- $ sudo authconfig --test [sudo] password for staff: sudo: unable to execute /sbin/authconfig: Permission denied -------- 8< ---------------- 8< ---------------- 8< ---------------- 8< -------- AVC: -------- 8< ---------------- 8< ---------------- 8< ---------------- 8< -------- time->Fri Jan 22 09:03:35 2021 type=PROCTITLE msg=audit(1611302615.729:148): proctitle=7375646F0061757468636F6E666967002D2D74657374 type=SYSCALL msg=audit(1611302615.729:148): arch=c000003e syscall=59 success=no exit=-13 a0=559e79623e78 a1=559e7961de78 a2=559e79673930 a3=1 items=0 ppid=1963 pid=1987 auid=1001 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts1 ses=4 comm="sudo" exe="/usr/bin/sudo" subj=staff_u:staff_r:staff_sudo_t:s0-s0:c0.c1023 key=(null) type=AVC msg=audit(1611302615.729:148): avc: denied { execute_no_trans } for pid=1987 comm="sudo" path="/usr/lib/python3.6/site-packages/authselect/authcompat.py" dev="dm-0" ino=18148211 scontext=staff_u:staff_r:staff_sudo_t:s0-s0:c0.c1023 tcontext=system_u:object_r:lib_t:s0 tclass=file permissive=0 -------- 8< ---------------- 8< ---------------- 8< ---------------- 8< -------- The reason for this is having /sbin/authconfig be a symlink to /usr/lib/python3.6/site-packages/authselect/authcompat.py which is labeled with lib_t, preventing the execution by staff_sudo_t. Same happens when being sysadm_sudo_t. Version-Release number of selected component (if applicable): authselect-compat-1.2.1-2.el8.x86_64 How reproducible: Always Steps to Reproduce: 1. Create a confined user that can sudo # useradd -Z staff_u -G wheel staff # echo "pass" | passwd --stdin staff 2. Switch to the user # ssh staff@localhost staff@localhost's password: pass $ id -Z staff_u:staff_r:staff_t:s0-s0:c0.c1023 3. Execute authconfig through sudo $ sudo authconfig --test [sudo] password for staff: pass sudo: unable to execute /sbin/authconfig: Permission denied Actual results: sudo: unable to execute /sbin/authconfig: Permission denied + AVC Expected results: works fine