Bug 1965985

This bug is cloned from bz1951323. On Fedora-Rawhide-20210529.n.0, kdump is working well with selinux-policy[1], may need to back-port it to rhel8.5.

[1] https://github.com/fedora-selinux/selinux-policy/pull/732

Original description of problem:
SELinux is preventing kdump from loading its generated initrd if `kdump` places its generated initrd in `/var/lib/kdump`, as may soon be the case for when `kdump` cannot place its generated initrd in the usual `/boot` on systems where `/boot` is mounted read-only, such as Fedora/RHEL CoreOS.
The default SELinux policies for `kdump`/`kexec` may need to be modified to address this.

The following is the `sealert` output from a build of Fedora CoreOS (which has `/boot` read-only) after `kdump` attempts to load the `kdump`-generated initrd placed at `/var/lib/kdump`:
```
SELinux is preventing kexec from read access on the file initramfs-5.10.19-200.fc33.x86_64kdump.img.

*****  Plugin catchall_labels (83.8 confidence) suggests   *******************

If you want to allow kexec to have read access on the initramfs-5.10.19-200.fc33.x86_64kdump.img file
Then you need to change the label on initramfs-5.10.19-200.fc33.x86_64kdump.img
Do
# semanage fcontext -a -t FILE_TYPE 'initramfs-5.10.19-200.fc33.x86_64kdump.img'
where FILE_TYPE is one of the following: NetworkManager_tmp_t, abrt_helper_exec_t, abrt_tmp_t, abrt_upload_watch_tmp_t, abrt_var_cache_t, abrt_var_run_t, admin_crontab_tmp_t, afs_cache_t, al.
Then execute:
restorecon -v 'initramfs-5.10.19-200.fc33.x86_64kdump.img'


*****  Plugin catchall (17.1 confidence) suggests   **************************

If you believe that kexec should be allowed read access on the initramfs-5.10.19-200.fc33.x86_64kdump.img 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:
# ausearch -c 'kexec' --raw | audit2allow -M my-kexec
# semodule -X 300 -i my-kexec.pp


Additional Information:
Source Context                system_u:system_r:kdump_t:s0
Target Context                system_u:object_r:var_lib_t:s0
Target Objects                initramfs-5.10.19-200.fc33.x86_64kdump.img [ file
                              ]
Source                        kexec
Source Path                   kexec
Port                          <Unknown>
Host                          <Unknown>
Source RPM Packages           
Target RPM Packages           
SELinux Policy RPM            selinux-policy-targeted-3.14.6-36.fc33.noarch
Local Policy RPM              <Unknown>
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     cosa-devsh
Platform                      Linux cosa-devsh 5.10.19-200.fc33.x86_64 #1 SMP
                              Fri Feb 26 16:21:30 UTC 2021 x86_64 x86_64
Alert Count                   2
First Seen                    2021-04-19 21:27:43 UTC
Last Seen                     2021-04-19 21:33:04 UTC
Local ID                      5ec95c86-81bf-4add-be38-5b46ac9fe88c

Raw Audit Messages
type=AVC msg=audit(1618867984.25:148): avc:  denied  { read } for  pid=1188 comm="kexec" name="initramfs-5.10.19-200.fc33.x86_64kdump.img" dev="vda4" ino=23069869 scontext=system_u:system_r:0


Hash: kexec,kdump_t,var_lib_t,file,read
```