Bug 2169520

Created attachment 1943915 [details]
SELinux type enforcement file for collectd-ipmi

Description of problem:
Hello!  I am running a RHEL 9 system with SELinux enforcing.  I have collectd-ipmi configured to pull IPMI data through the local IPMI interface (/dev/ipmi0).  collectd's SELinux module does not allow this access, so it is failing.  I'm opening this bug to report the issue, and to ask if a SELinux module could please be added to the collectd-ipmi package.

Version-Release number of selected component (if applicable):
collectd-5.12.0-24.el9.x86_64
collectd-ipmi-5.12.0-24.el9.x86_64

How reproducible:
This appears to always reproduce, as long as SELinux is enabled and enforcing.

Steps to Reproduce:
1. Build a RHEL 9.1 system with SELinux enabled (and enforcing).

2. Install `epel-release`, then install `collectd` & `collectd-ipmi`.

3. Create a file at path `/etc/collectd.d/ipmi.conf`, containing the following five lines:

LoadPlugin "ipmi"
<Plugin "ipmi">
  <Instance "local">
  </Instance>
</Plugin>

5. Enable and start the `collectd` service.

Actual results:

Collectd starts, but reports the following issue with the ipmi module:

Feb 13 11:27:55 srcc-globus-dtn02.stanford.edu collectd[217029]: ipmi plugin: ipmi_smi_setup_con failed for `local`: OS: Permission denied
Feb 13 11:27:55 srcc-globus-dtn02.stanford.edu collectd[217029]: ipmi plugin: c_ipmi_thread_init failed.
Feb 13 11:27:55 srcc-globus-dtn02.stanford.edu collectd[217029]: ipmi plugin: c_ipmi_read: I'm not active, returning false.

The following entries are recorded in the audit logs:

type=PROCTITLE msg=audit(1676316989.876:2139): proctitle="/usr/sbin/collectd"
type=SYSCALL msg=audit(1676316989.876:2139): arch=c000003e syscall=257 success=no exit=-13 a0=ffffff9c a1=7ffbecd72d60 a2=2 a3=0 items=0 ppid=1 pid=217433 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="ipmi" exe="/usr/sbin/collectd" subj=system_u:system_r:collectd_t:s0 key=(null)
type=AVC msg=audit(1676316989.876:2139): avc:  denied  { read write } for  pid=217433 comm="ipmi" name="ipmi0" dev="devtmpfs" ino=464 scontext=system_u:system_r:collectd_t:s0 tcontext=system_u:object_r:ipmi_device_t:s0 tclass=chr_file permissive=0
type=PROCTITLE msg=audit(1676317473.800:2146): proctitle="/usr/sbin/collectd"
type=SYSCALL msg=audit(1676317473.800:2146): arch=c000003e syscall=257 success=no exit=-13 a0=ffffff9c a1=7fc8200aed60 a2=2 a3=0 items=0 ppid=1 pid=217744 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="ipmi" exe="/usr/sbin/collectd" subj=system_u:system_r:collectd_t:s0 key=(null)
type=AVC msg=audit(1676317473.800:2146): avc:  denied  { open } for  pid=217744 comm="ipmi" path="/dev/ipmi0" dev="devtmpfs" ino=464 scontext=system_u:system_r:collectd_t:s0 tcontext=system_u:object_r:ipmi_device_t:s0 tclass=chr_file permissive=0
type=PROCTITLE msg=audit(1676317769.843:2155): proctitle="/usr/sbin/collectd"
type=SYSCALL msg=audit(1676317769.843:2155): arch=c000003e syscall=16 success=no exit=-13 a0=5 a1=8028690d a2=7f3dc8df8a20 a3=7f3dc40048f0 items=0 ppid=1 pid=217841 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="ipmi" exe="/usr/sbin/collectd" subj=system_u:system_r:collectd_t:s0 key=(null)
type=AVC msg=audit(1676317769.843:2155): avc:  denied  { ioctl } for  pid=217841 comm="ipmi" path="/dev/ipmi0" dev="devtmpfs" ino=464 ioctlcmd=0x690d scontext=system_u:system_r:collectd_t:s0 tcontext=system_u:object_r:ipmi_device_t:s0 tclass=chr_file permissive=0

Expected results:
I expected the `collectd-ipmi` package to include a SELinux module, so that it would be able to access the local IPMI device.


Additional info:
collectd's IPMI module is able to talk to IPMI using the local IPMI device (`/dev/ipmi0`), if it exists (which it often does, on most servers).  However, collectd's default SELinux configuration does not allow it to perform the operations needed to talk to the local IPMI device.  the `collectd-ipmi` module sees a "Permission Denied" error, and SELinux logs what it did into the audit log.

Using the steps at https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/5/html/deployment_guide/sec-sel-building-policy-module, Section 5.12, I was able to build and install an SELinux policy module that resolves the error.  I'm attaching the type enforcement file that I made, over multiple iterations of `ausearch -m AVC` and `audit2allow`.  You can use the file yourself by copying it to `/tmp/collectd-ipmi.te` on your server and running these three commands:

checkmodule -m -o /tmp/collectd-ipmi.mod /tmp/collectd-ipmi.te
semodule_package -o /tmp/collectd-ipmi.pp -m /tmp/collectd-ipmi.mod
semodule -i /tmp/collectd-ipmi.pp

If I understand things correctly, the files in `/tmp` do not need to be saved, for the installed module to persist across reboots.