Bug 1455631
| Summary: | sbd daemon can not access /proc/sysrq-trigger | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Miroslav Lisik <mlisik> |
| Component: | selinux-policy | Assignee: | Lukas Vrabec <lvrabec> |
| Status: | CLOSED ERRATA | QA Contact: | Milos Malik <mmalik> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 7.4 | CC: | cfeist, kwenning, lvrabec, mgrepl, mmalik, plautrba, pvrabec, ssekidde |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-08-01 15:26:23 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: | 1413951 | ||
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, 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-2017:1861 |
Description of problem: SE-Linux prevents sbd from accessing the /proc/sysrq-trigger. Version-Release number of selected component (if applicable): # rpm -qa selinux\* selinux-policy-3.13.1-151.el7.noarch selinux-policy-targeted-3.13.1-151.el7.noarch selinux-policy-devel-3.13.1-151.el7.noarch How reproducible: always Steps to Reproduce: 1. install sbd package [root@virt-146 ~]# yum -y -q install sbd 2. Change sbd configuration file at /etc/sysconfig/sbd, set SBD_DEVICE to your testing device [root@virt-146 ~]# cat > /etc/sysconfig/sbd <<EOF > SBD_DELAY_START=no > SBD_DEVICE="/dev/sda" > SBD_PACEMAKER=yes > SBD_STARTMODE=always > SBD_WATCHDOG_DEV=/dev/null > SBD_WATCHDOG_TIMEOUT=5 > EOF 3. Create sbd header on the block device. [root@virt-146 ~]# sbd -d /dev/sda create Initializing device /dev/sda Creating version 2.1 header on device 4 (uuid: 9f69bcb1-f563-4095-9b2f-31515d833398) Initializing 255 slots on device 4 Device /dev/sda is initialized. 4. Modify sbd.service file to enable start service manualy. [root@virt-146 ~]# sed -i "s/^RefuseManualStart=.*$/RefuseManualStart=false/" /usr/lib/systemd/system/sbd.service [root@virt-146 ~]# sed -i "s/^RefuseManualStop=.*$/RefuseManualStop=false/" /usr/lib/systemd/system/sbd.service [root@virt-146 ~]# systemctl daemon-reload 5. Start the sbd service: [root@virt-146 ~]# systemctl start sbd [root@virt-146 ~]# systemctl status sbd ● sbd.service - Shared-storage based fencing daemon Loaded: loaded (/usr/lib/systemd/system/sbd.service; disabled; vendor preset: disabled) Active: active (running) since Thu 2017-05-25 18:01:49 CEST; 2s ago Process: 11976 ExecStart=/usr/sbin/sbd $SBD_OPTS -p /var/run/sbd.pid watch (code=exited, status=0/SUCCESS) Main PID: 11977 (sbd) CGroup: /system.slice/sbd.service ├─11977 sbd: inquisitor ├─11978 sbd: watcher: /dev/sda - slot: 0 - uuid: 91c62c77-bd37-40be-9cfc-a2c93dce646c ├─11979 sbd: watcher: Pacemaker └─11980 sbd: watcher: Cluster May 25 18:01:46 virt-146.cluster-qe.lab.eng.brq.redhat.com systemd[1]: Starting Shared-storage bas.... May 25 18:01:49 virt-146.cluster-qe.lab.eng.brq.redhat.com systemd[1]: Started Shared-storage base.... Hint: Some lines were ellipsized, use -l to show in full. 6. Write 'reset' message to the slot on the sbd device (use sbd's list command to get the slot name). [root@virt-146 ~]# sbd -d /dev/sda list 0 virt-146.cluster-qe.lab.eng.brq.redhat.com clear [root@virt-146 ~]# sbd -d /dev/sda message virt-146.cluster-qe.lab.eng.brq.redhat.com reset 7. Check the avc messages Actual results: Following SELinux denial appeared in enforcing mode: ---- time->Thu May 25 18:02:34 2017 type=PROCTITLE msg=audit(1495728154.529:3357): proctitle=7362643A20776174636865723A202F6465762F736461202D20736C6F743A2030202D20757569643A2039316336326337372D626433372D343062652D396366632D613263393364636536343663 type=SYSCALL msg=audit(1495728154.529:3357): arch=c000003e syscall=2 success=no exit=-13 a0=40bcb0 a1=441 a2=1b6 a3=24 items=0 ppid=11977 pid=11978 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="sbd" exe="/usr/sbin/sbd" subj=system_u:system_r:sbd_t:s0 key=(null) type=AVC msg=audit(1495728154.529:3357): avc: denied { append } for pid=11978 comm="sbd" name="sysrq-trigger" dev="proc" ino=4026532058 scontext=system_u:system_r:sbd_t:s0 tcontext=system_u:object_r:sysctl_t:s0 tclass=file ---- time->Thu May 25 18:02:34 2017 type=PROCTITLE msg=audit(1495728154.530:3358): proctitle=7362643A20776174636865723A202F6465762F736461202D20736C6F743A2030202D20757569643A2039316336326337372D626433372D343062652D396366632D613263393364636536343663 type=SYSCALL msg=audit(1495728154.530:3358): arch=c000003e syscall=169 success=no exit=-1 a0=fffffffffee1dead a1=28121969 a2=1234567 a3=7ffe588f0d60 items=0 ppid=11977 pid=11978 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="sbd" exe="/usr/sbin/sbd" subj=system_u:system_r:sbd_t:s0 key=(null) type=AVC msg=audit(1495728154.530:3358): avc: denied { sys_boot } for pid=11978 comm="sbd" capability=22 scontext=system_u:system_r:sbd_t:s0 tcontext=system_u:system_r:sbd_t:s0 tclass=capability Expected results: No AVC messages. The sbd daemon should be allowed to write into /proc/sysrq-trigger and machine should reboot. ------------------------------------------------------- Additional info: a) No AVC messages in the permissive mode because machine immediately reboots. b) 'reset' message was writen: [root@virt-146 ~]# sbd -d /dev/sda list 0 virt-146.cluster-qe.lab.eng.brq.redhat.com reset virt-146.cluster-qe.lab.eng.brq.redhat.com c) status of sbd daemon [root@virt-146 ~]# systemctl status sbd ● sbd.service - Shared-storage based fencing daemon Loaded: loaded (/usr/lib/systemd/system/sbd.service; disabled; vendor preset: disabled) Active: failed (Result: timeout) since Thu 2017-05-25 18:04:12 CEST; 3min 6s ago Process: 12117 ExecStop=/usr/bin/kill -TERM $MAINPID (code=exited, status=1/FAILURE) Process: 11976 ExecStart=/usr/sbin/sbd $SBD_OPTS -p /var/run/sbd.pid watch (code=exited, status=0/SUCCESS) Main PID: 11977 (code=exited, status=1/FAILURE) May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com kill[12117]: -p, --pid print pids without signaling them May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com kill[12117]: -l, --list [=<signal>] list signal names, or convert one to a name May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com kill[12117]: -L, --table list signal names and numbers May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com kill[12117]: -h, --help display this help and exit May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com kill[12117]: -V, --version output version information and exit May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com kill[12117]: For more details see kill(1). May 25 18:02:42 virt-146.cluster-qe.lab.eng.brq.redhat.com systemd[1]: sbd.service: control process exited, code=exited status=1 May 25 18:04:12 virt-146.cluster-qe.lab.eng.brq.redhat.com systemd[1]: sbd.service stop-sigterm timed out. Killing. May 25 18:04:12 virt-146.cluster-qe.lab.eng.brq.redhat.com systemd[1]: Unit sbd.service entered failed state. May 25 18:04:12 virt-146.cluster-qe.lab.eng.brq.redhat.com systemd[1]: sbd.service failed. d) snippet from /var/log/messages: May 25 18:01:46 virt-146 systemd: Starting Shared-storage based fencing daemon... May 25 18:01:49 virt-146 systemd: Started Shared-storage based fencing daemon. May 25 18:02:34 virt-146 sbd[11978]: /dev/sda: emerg: do_exit: Rebooting system: reboot May 25 18:02:34 virt-146 sbd[11978]: /dev/sda: error: sysrq_trigger: Opening sysrq-trigger failed.: Permission denied (13) May 25 18:02:34 virt-146 sbd[11978]: /dev/sda: error: do_exit: Reboot failed: Operation not permitted (1) May 25 18:02:34 virt-146 sbd[11977]: warning: cleanup_servant_by_pid: Servant for /dev/sda (pid: 11978) has terminated May 25 18:02:35 virt-146 sbd[12091]: /dev/sda: emerg: do_exit: Rebooting system: reboot May 25 18:02:35 virt-146 sbd[12091]: /dev/sda: error: sysrq_trigger: Opening sysrq-trigger failed.: Permission denied (13) May 25 18:02:35 virt-146 sbd[12091]: /dev/sda: error: do_exit: Reboot failed: Operation not permitted (1) May 25 18:02:35 virt-146 sbd[11977]: warning: cleanup_servant_by_pid: Servant for /dev/sda (pid: 12091) has terminated May 25 18:02:40 virt-146 sbd[11977]: warning: inquisitor_child: Latency: No liveness for 4 s exceeds threshold of 3 s (healthy servants: 0) May 25 18:02:41 virt-146 sbd[11977]: warning: inquisitor_child: Latency: No liveness for 5 s exceeds threshold of 3 s (healthy servants: 0) May 25 18:02:41 virt-146 sbd[12109]: /dev/sda: emerg: do_exit: Rebooting system: reboot May 25 18:02:41 virt-146 sbd[12109]: /dev/sda: error: sysrq_trigger: Opening sysrq-trigger failed.: Permission denied (13) May 25 18:02:41 virt-146 sbd[12109]: /dev/sda: error: do_exit: Reboot failed: Operation not permitted (1) May 25 18:02:41 virt-146 sbd[11977]: warning: cleanup_servant_by_pid: Servant for /dev/sda (pid: 12109) has terminated May 25 18:02:41 virt-146 sbd[11977]: warning: inquisitor_child: Latency: No liveness for 5 s exceeds threshold of 3 s (healthy servants: 0) May 25 18:02:41 virt-146 sbd[11977]: warning: inquisitor_child: Latency: No liveness for 5 s exceeds threshold of 3 s (healthy servants: 0) May 25 18:02:42 virt-146 sbd[11977]: emerg: do_exit: Rebooting system: reboot May 25 18:02:42 virt-146 sbd[11977]: error: sysrq_trigger: Opening sysrq-trigger failed.: Permission denied (13) May 25 18:02:42 virt-146 sbd[11977]: error: do_exit: Reboot failed: Operation not permitted (1) May 25 18:02:42 virt-146 systemd: sbd.service: main process exited, code=exited, status=1/FAILURE May 25 18:02:42 virt-146 kill: Usage: May 25 18:02:42 virt-146 kill: kill [options] <pid|name> [...] May 25 18:02:42 virt-146 kill: Options: May 25 18:02:42 virt-146 kill: -a, --all do not restrict the name-to-pid conversion to processes May 25 18:02:42 virt-146 kill: with the same uid as the present process May 25 18:02:42 virt-146 kill: -s, --signal <sig> send specified signal May 25 18:02:42 virt-146 kill: -q, --queue <sig> use sigqueue(2) rather than kill(2) May 25 18:02:42 virt-146 kill: -p, --pid print pids without signaling them May 25 18:02:42 virt-146 kill: -l, --list [=<signal>] list signal names, or convert one to a name May 25 18:02:42 virt-146 kill: -L, --table list signal names and numbers May 25 18:02:42 virt-146 kill: -h, --help display this help and exit May 25 18:02:42 virt-146 kill: -V, --version output version information and exit May 25 18:02:42 virt-146 kill: For more details see kill(1). May 25 18:02:42 virt-146 systemd: sbd.service: control process exited, code=exited status=1 May 25 18:04:12 virt-146 systemd: sbd.service stop-sigterm timed out. Killing. May 25 18:04:12 virt-146 systemd: Unit sbd.service entered failed state. May 25 18:04:12 virt-146 systemd: sbd.service failed.