Files
debian-cis/bin/hardening/disable_udf.sh
Damien Cavagnini 3753a72723 refactor: is_kernel_option_enabled
Current "is_kernel_option_enabled" function is doing many things, like checking for a kernel option AND checking a kernel module state AND checking if it is disabled
We split it in different functions:
        - is_kernel_monolithic
        - is_kernel_option_enabled -> check for a kernel configuration in the running kernel
        - is_kernel_module_loaded -> check if a module is currently loaded
        - is_kernel_module_available -> check if a module is configured in all available kernel configs
        - is_kernel_module_disabled   -> check if a kernel module is disabled in the modprobe configuration

Also:

- update its behaviour to debian 12 CIS recommendation, to check if a module is "available in ANY installed kernel"
- fix "disable_usb_storage" to look for correct module name once loaded : issue #249
- the associated checks now check separately if the module is loaded, and if it is configured
- for checks about kernel module presence, the "apply" function now manages to disable the module in the modprobe configuration (if kernel not monolithic) (but still wont unload it)
2025-07-11 09:16:27 +02:00

98 lines
3.2 KiB
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#!/bin/bash
# run-shellcheck
#
# CIS Debian Hardening
#
#
# Ensure mounting of udf filesystems is disabled (Scored)
#
set -e # One error, it's over
set -u # One variable unset, it's over
# shellcheck disable=2034
HARDENING_LEVEL=2
# shellcheck disable=2034
DESCRIPTION="Disable mounting of udf filesystems."
KERNEL_OPTION="CONFIG_UDF_FS"
MODULE_NAME="udf"
# This function will be called if the script status is on enabled / audit mode
audit() {
if [ "$IS_CONTAINER" -eq 1 ]; then
# In an unprivileged container, the kernel modules are host dependent, so you should consider enforcing it
ok "Container detected, consider host enforcing or disable this check!"
else
is_kernel_module_loaded "$KERNEL_OPTION" "$MODULE_NAME"
if [ "$FNRET" -eq 0 ]; then # 0 means true in bash, so it IS activated
crit "$MODULE_NAME is loaded!"
else
ok "$MODULE_NAME is not loaded"
fi
if [ "$IS_MONOLITHIC_KERNEL" -eq 1 ]; then
is_kernel_module_disabled "$MODULE_NAME"
if [ "$FNRET" -eq 0 ]; then
ok "$MODULE_NAME is disabled in the modprobe configuration"
else
is_kernel_module_available "$KERNEL_OPTION"
if [ "$FNRET" -eq 0 ]; then
crit "$MODULE_NAME is available in some kernel config, but not disabled"
else
ok "$MODULE_NAME is not available in any kernel config"
fi
fi
fi
fi
}
# This function will be called if the script status is on enabled mode
apply() {
if [ "$IS_CONTAINER" -eq 1 ]; then
# In an unprivileged container, the kernel modules are host dependent, so you should consider enforcing it
ok "Container detected, consider host enforcing!"
else
is_kernel_module_loaded "$KERNEL_OPTION" "$LOADED_MODULE_NAME"
if [ "$FNRET" -eq 0 ]; then # 0 means true in bash, so it IS activated
crit "$LOADED_MODULE_NAME is loaded!"
warn "I wont unload the module, unload it manually or recompile the kernel if needed"
fi
if [ "$IS_MONOLITHIC_KERNEL" -eq 1 ]; then
is_kernel_module_disabled "$MODULE_NAME"
if [ "$FNRET" -eq 1 ]; then
echo "install $MODULE_NAME /bin/true" >>/etc/modprobe.d/"$MODULE_NAME".conf
info "$MODULE_NAME has been disabled in the modprobe configuration"
fi
fi
fi
}
# This function will check config parameters required
check_config() {
:
}
# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
# shellcheck source=../../debian/default
. /etc/default/cis-hardening
fi
if [ -z "$CIS_LIB_DIR" ]; then
echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
echo "Cannot source CIS_LIB_DIR variable, aborting."
exit 128
fi
# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
# shellcheck source=../../lib/main.sh
. "${CIS_LIB_DIR}"/main.sh
else
echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
exit 128
fi