Bug 951659
| Summary: | selinux-policy-targeted-3.11.1-87.fc18 blocks winbindd from unlink/write to /var/tmp/host_0 | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Jonathan Abbey <jonabbey> |
| Component: | selinux-policy-targeted | Assignee: | Miroslav Grepl <mgrepl> |
| Status: | CLOSED ERRATA | QA Contact: | Ben Levenson <benl> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 18 | CC: | dwalsh |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2013-04-18 02:53:50 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: | |||
524e73638aee5f5e8e29d126bc4b2d99d190cc3f fixes this in Git. Thanks. I should say that the system that stayed working may have had its /var/tmp/host_0 file labelled differently before I did the updates.. I don't know for sure that the updates relabeled that file on the system that broke. I am surprised we did not already allow this. Yeah. I checked the srpm for this selinux-policy build, but I didn't see anything in the changelog that mentioned this changing recently, and I didn't know where I could find revision control for it to look for myself. Well it is more about correcting the labelling and it looks like you were lucky enough to not have /var/tmp relabeled. So /var/tmp/host_0 is meant to retain the user_tmp_t labeling? I was thinking winbind_t was just lacking the appropriate permission to unlink/write krb5_host_rcache_t.. No winbind_t was just lacking the appropriate permission to unlink/write krb5_host_rcache_t.. Which is now fixed in git, and hopefully Miroslav will be sending out the fix in the next update. It should be labeled as kerberos content. selinux-policy-3.11.1-90.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/selinux-policy-3.11.1-90.fc18 Package selinux-policy-3.11.1-90.fc18: * should fix your issue, * was pushed to the Fedora 18 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing selinux-policy-3.11.1-90.fc18' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2013-5742/selinux-policy-3.11.1-90.fc18 then log in and leave karma (feedback). selinux-policy-3.11.1-90.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report. |
Description of problem: Running winbind on Fedora 18. After updating selinux-policy-targeted, winbind daemons can no longer unlink/write to /var/tmp/host_0 with label system_u:object_r:krb5_host_rcache_t:s0 Version-Release number of selected component (if applicable): selinux-policy-targeted-3.11.1-87.fc18.noarch How reproducible: Attempt to ssh to system using winbind PAM module for logins after selinux-policy-targeted is updated to 3.11.1-87.fc18.noarch Steps to Reproduce: 1. yum update selinux-policy selinux-policy-targeted 2. ssh to system Actual results: Login fails, messages appear in /var/log/audit.log: type=AVC msg=audit(1365785661.223:72016): avc: denied { write } for pid=22603 comm="winbindd" name="host_0" dev="dm-1" ino=920593 scontext=system_u:system_r:winbind_t:s0 tcontext=system_u:object_r:krb5_host_rcache_t:s0 tclass=file type=AVC msg=audit(1365785661.223:72017): avc: denied { unlink } for pid=22603 comm="winbindd" name="host_0" dev="dm-1" ino=920593 scontext=system_u:system_r:winbind_t:s0 tcontext=system_u:object_r:krb5_host_rcache_t:s0 tclass=file type=AVC msg=audit(1365785662.923:72018): avc: denied { write } for pid=22603 comm="winbindd" name="host_0" dev="dm-1" ino=920593 scontext=system_u:system_r:winbind_t:s0 tcontext=system_u:object_r:krb5_host_rcache_t:s0 tclass=file Expected results: Successful login, no AVC deny messages in /var/log/audit.log. Additional info: I updated the selinux-policy and selinux-policy-targeted RPMs on two Fedora 18 systems that should be essentially identical in configuration, both using winbind to an Active Directory controller for PAM. On one of the systems, /var/tmp/host_0 got relabeled (by the selinux-policy-targeted update?) to type krb5_host_rcache_t, whereupon logins started failing. On the other system, /var/tmp/host_0 kept the type label 'user_tmp_t', and logins kept working. I fixed the problem on the broken system by doing 'chcon -t user_tmp_t /var/tmp/host_0', but running 'restorecon -v -n /var/tmp/host_0' on each system shows that both systems think that 'krb5_host_rcache_t' is the proper type label for the file. I haven't tried relabeling and rebooting either system, so I don't know if this problem would resolve with the new policy after a reboot, but I tried doing a 'systemctl restart winbind' several times on the affected system, and logins did not resume functioning until I manually relabeled /var/tmp/host_0 to user_tmp_t. Running sealert on the error recorded in /var/log/messages gave the following: SELinux is preventing /usr/sbin/winbindd (deleted) from write access on the file host_0. ***** Plugin catchall (100. confidence) suggests *************************** If you believe that winbindd (deleted) should be allowed write access on the host_0 file by default. Then you should report this as a bug. You can generate a local policy module to allow this access. Do allow this access for now by executing: # grep winbindd /var/log/audit/audit.log | audit2allow -M mypol # semodule -i mypol.pp Additional Information: Source Context system_u:system_r:winbind_t:s0 Target Context system_u:object_r:krb5_host_rcache_t:s0 Target Objects host_0 [ file ] Source winbindd Source Path /usr/sbin/winbindd (deleted) Port <Unknown> Host xportal2.arlut.utexas.edu Source RPM Packages samba-winbind-4.0.4-3.fc18.x86_64 Target RPM Packages Policy RPM selinux-policy-3.11.1-87.fc18.noarch Selinux Enabled True Policy Type targeted Enforcing Mode Enforcing Host Name xportal2.arlut.utexas.edu Platform Linux xportal2.arlut.utexas.edu 3.8.3-203.fc18.x86_64 #1 SMP Mon Mar 18 12:59:28 UTC 2013 x86_64 x86_64 Alert Count 79 First Seen 2013-04-12 10:13:41 CDT Last Seen 2013-04-12 11:54:37 CDT Local ID 5271b3fd-bec9-46ac-a988-a6a894e42719 Raw Audit Messages type=AVC msg=audit(1365785677.314:72031): avc: denied { write } for pid=25014 comm="winbindd" name="host_0" dev="dm-1" ino=920593 scontext=system_u:system_r:winbind_t:s0 tcontext=system_u:object_r:krb5_host_rcache_t:s0 tclass=file type=SYSCALL msg=audit(1365785677.314:72031): arch=x86_64 syscall=open success=no exit=EACCES a0=23de060 a1=2 a2=180 a3=10 items=0 ppid=25013 pid=25014 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 ses=4294967295 tty=(none) comm=winbindd exe=/usr/sbin/winbindd subj=system_u:system_r:winbind_t:s0 key=(null) Hash: winbindd,winbind_t,krb5_host_rcache_t,file,write audit2allow #============= winbind_t ============== allow winbind_t krb5_host_rcache_t:file write; audit2allow -R require { type winbind_t; } #============= winbind_t ============== kerberos_filetrans_named_content(winbind_t)