Information
Monitor the loading and unloading of kernel modules. The programs insmod (install a kernel module), rmmod (remove a kernel module), and modprobe (a more sophisticated program to load and unload modules, as well as some other features) control loading and unloading of modules. The init_module (load a module) and delete_module (delete a module) system calls control loading and unloading of modules. Any execution of the loading and unloading module programs and system calls will trigger an audit record with an identifier of 'modules'.
Rationale:
Monitoring the use of insmod , rmmod and modprobe could provide system administrators with evidence that an unauthorized user loaded or unloaded a kernel module, possibly compromising the security of the system. Monitoring of the init_module and delete_module system calls would reflect an unauthorized user attempting to use a different program to load and unload modules.
Solution
For 32 bit systems Edit or create a file in the /etc/audit/rules.d/ directory ending in .rules
Example: vi /etc/audit/rules.d/audit.rules
and add the following lines:
-w /sbin/insmod -p x -k modules
-w /sbin/rmmod -p x -k modules
-w /sbin/modprobe -p x -k modules
-a always,exit -F arch=b32 -S init_module -S delete_module -k modules
For 64 bit systems Edit or create a file in the /etc/audit/rules.d/ directory ending in .rules
Example: vi /etc/audit/rules.d/audit.rules
and add the following lines:
-w /sbin/insmod -p x -k modules
-w /sbin/rmmod -p x -k modules
-w /sbin/modprobe -p x -k modules
-a always,exit -F arch=b64 -S init_module -S delete_module -k modules
Notes:
Reloading the auditd config to set active settings may require a system reboot.
This Benchmark recommendation maps to:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide:
Version 2, Release: 3 Benchmark Date: 26 Apr 2019
Vul ID: V-72187
Rule ID: SV-86811r4_rule
STIG ID: RHEL-07-030820
Severity: CAT II
Vul ID: V-72189
Rule ID: SV-86813r4_rule
STIG ID: RHEL-07-030830
Severity: CAT II