Bug 1566168

Summary: SELinux is preventing /usr/lib/systemd/systemd-resolved from 'read' accesses on the directory /run/dbus.
Product: [Fedora] Fedora Reporter: Giovanni Campagna <scampa.giovanni>
Component: selinux-policyAssignee: Lukas Vrabec <lvrabec>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 28CC: bartoc+fedora_bugs, dwalsh, lvrabec, mgrepl, plautrba, pmoore, ppywlkiqletw, rockonthemoonfm, scampa.giovanni
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Unspecified   
Whiteboard: abrt_hash:e7f8bc9b1633501a3f43b1cbe5fde6c21cd2039fbe5333ce6f1205dd89a030d9;VARIANT_ID=workstation;
Fixed In Version: selinux-policy-3.14.1-25.fc28 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-05-23 15:40:26 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Giovanni Campagna 2018-04-11 16:29:41 UTC
Description of problem:
It just happens with systemd-resolved enabled.

systemd-resolved is a system bus daemon, it seems reasonable it accesses /run/dbus
SELinux is preventing /usr/lib/systemd/systemd-resolved from 'read' accesses on the directory /run/dbus.

*****  Plugin catchall (100. confidence) suggests   **************************

If you believe that systemd-resolved should be allowed read access on the dbus directory 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:
# ausearch -c 'systemd-resolve' --raw | audit2allow -M my-systemdresolve
# semodule -X 300 -i my-systemdresolve.pp

Additional Information:
Source Context                system_u:system_r:systemd_resolved_t:s0
Target Context                system_u:object_r:system_dbusd_var_run_t:s0
Target Objects                /run/dbus [ dir ]
Source                        systemd-resolve
Source Path                   /usr/lib/systemd/systemd-resolved
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           systemd-238-7.fc28.x86_64
Target RPM Packages           dbus-1.12.0-1.fc28.x86_64
Policy RPM                    selinux-policy-3.14.1-19.fc28.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 4.16.0-300.fc28.x86_64 #1 SMP Tue
                              Apr 3 03:44:37 UTC 2018 x86_64 x86_64
Alert Count                   5
First Seen                    2018-03-31 17:48:56 PDT
Last Seen                     2018-04-10 21:21:29 PDT
Local ID                      02efbf8f-bdd3-4529-b1a9-69ec4198345a

Raw Audit Messages
type=AVC msg=audit(1523420489.160:102): avc:  denied  { read } for  pid=963 comm="systemd-resolve" name="dbus" dev="tmpfs" ino=23943 scontext=system_u:system_r:systemd_resolved_t:s0 tcontext=system_u:object_r:system_dbusd_var_run_t:s0 tclass=dir permissive=0


type=SYSCALL msg=audit(1523420489.160:102): arch=x86_64 syscall=inotify_add_watch success=no exit=EACCES a0=f a1=562c4a16ee60 a2=2000d84 a3=63 items=1 ppid=1 pid=963 auid=4294967295 uid=997 gid=996 euid=997 suid=997 fsuid=997 egid=996 sgid=996 fsgid=996 tty=(none) ses=4294967295 comm=systemd-resolve exe=/usr/lib/systemd/systemd-resolved subj=system_u:system_r:systemd_resolved_t:s0 key=(null)

type=CWD msg=audit(1523420489.160:102): cwd=/

type=PATH msg=audit(1523420489.160:102): item=0 name=/run/dbus inode=23943 dev=00:17 mode=040755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:system_dbusd_var_run_t:s0 nametype=NORMAL cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0

Hash: systemd-resolve,systemd_resolved_t,system_dbusd_var_run_t,dir,read

Version-Release number of selected component:
selinux-policy-3.14.1-19.fc28.noarch

Additional info:
component:      selinux-policy
reporter:       libreport-2.9.4
hashmarkername: setroubleshoot
kernel:         4.16.0-300.fc28.x86_64
type:           libreport

Comment 1 Lukas Vrabec 2018-04-17 13:02:23 UTC
Hi, 

Are you able to reproduce it? 

Thanks,
Lukas.

Comment 2 Giovanni Campagna 2018-04-23 01:43:31 UTC
It still happens (I just got a new notification right now).
I cannot reproduce it precisely.

Regardless, this does not seem like a difficult bug to diagnose: systemd-resolved is a system bus daemon, hence it needs to access /run/dbus.
(On a cursory read it seems it is trying to check if the dbus socket is there, and then set an inotify watch on it - which makes sense, as systemd-resolved needs to be able to survive the system bus disappearing or appearing late during boot)
The bug is just in the policy.

Comment 3 Charles Barto 2018-04-25 13:27:54 UTC
Description of problem:
This started happening after updating last night. I'm domain joined and have 
tried getting DNS from both/either RAs and DHCPv6,
even entering in manual addresses in network manager does 
not work (which sould be consistent with resolved not
being able to read dbus).

Version-Release number of selected component:
selinux-policy-3.14.1-21.fc28.noarch

Additional info:
reporter:       libreport-2.9.4
hashmarkername: setroubleshoot
kernel:         4.16.3-300.fc28.x86_64
type:           libreport

Comment 4 Villy Kruse 2018-04-30 04:53:41 UTC
Description of problem:
This occurs when running systemd-resolvd in the new FC28 version.
No problem in the latest FC27 version.

Version-Release number of selected component:
selinux-policy-3.14.1-21.fc28.noarch

Additional info:
reporter:       libreport-2.9.4
hashmarkername: setroubleshoot
kernel:         4.16.4-300.fc28.x86_64
type:           libreport

Comment 5 Fedora Update System 2018-05-21 09:56:24 UTC
selinux-policy-3.14.1-25.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-d19ffdb4ba

Comment 6 Fedora Update System 2018-05-21 17:15:40 UTC
selinux-policy-3.14.1-25.fc28 has been pushed to the Fedora 28 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-d19ffdb4ba

Comment 7 Fedora Update System 2018-05-23 15:40:26 UTC
selinux-policy-3.14.1-25.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.