Security-Enhanced Linux secures the readahead processes via flexible mandatory access control.
The readahead processes execute with the readahead_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
ps -eZ | grep readahead_t
The readahead_t SELinux type can be entered via the readahead_exec_t file type.
The default entrypoint paths for the readahead_t domain are the following:
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux readahead policy is very flexible allowing users to setup their readahead processes in as secure a method as possible.
The following process types are defined for readahead:
Note: semanage permissive -a readahead_t can be used to make the process type readahead_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.
setsebool -P fips_mode 1
The SELinux process type readahead_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.
You can see the context of a file using the -Z option to lsP Policy governs the access confined processes have to these files. SELinux readahead policy is very flexible allowing users to setup their readahead processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the readahead, if you wanted to store files with these types in a diffent paths, you need to execute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk.
semanage fcontext -a -t readahead_var_run_t '/srv/myreadahead_content(/.*)?'
restorecon -R -v /srv/myreadahead_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for readahead:
- Set files with the readahead_exec_t type, if you want to transition an executable to the readahead_t domain.
- Set files with the readahead_var_lib_t type, if you want to store the readahead files under the /var/lib directory.
- Set files with the readahead_var_run_t type, if you want to store the readahead files under the /run or /var/run directory.
Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels.
semanage permissive can also be used to manipulate whether or not a process type is permissive.
semanage module can also be used to enable/disable/install/remove policy modules.
semanage boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux policy settings.