path: root/include/tests_kernel

#!/bin/sh

#################################################################################
#
#   Lynis
# ------------------
#
# Copyright 2007-2014, Michael Boelen (michael@rootkit.nl), The Netherlands
# Web site: http://www.rootkit.nl
#
# Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
# welcome to redistribute it under the terms of the GNU General Public License.
# See LICENSE file for usage of this software.
#
#################################################################################
#
# Kernel
#
#################################################################################
#
    InsertSection "Kernel"
#
#################################################################################
#
    CORE_DUMPS_DISABLED=0
    CPU_PAE=0
    CPU_NX=0
#
#################################################################################
#
    # Test        : KRNL-5622
    # Description : Check default run level on Linux machines
    Register --test-no KRNL-5622 --os Linux --weight L --network NO --description "Determine Linux default run level"
    if [ ${SKIPTEST} -eq 0 ]; then
        # Checking if we can find the systemd default target
        logtext "Test: Checking for systemd default.target"
        if [ -L /etc/systemd/system/default.target ]; then
            logtext "Result: symlink found"
            if [ ! "${READLINKBINARY}" = "" ]; then
                FIND=`${READLINKBINARY} /etc/systemd/system/default.target`
                if [ "${FIND}" = "" ]; then
                    logtext "Exception: can't find the target of the symlink of /etc/systemd/system/default.target"
                    ReportException "${TEST_NO}:01"
                  else
                    FIND2=`echo ${FIND} | egrep "runlevel5|graphical"`
                    if [ ! "${FIND2}" = "" ]; then
                        logtext "Result: Found match on runlevel5/graphical"
                        Display --indent 2 --text "- Checking default runlevel..." --result "runlevel 5" --color GREEN
                        report "linux_default_runlevel=5"
                      else 
                        logtext "Result: No match found on runlevel, defaulting to runlevel 3"
                        Display --indent 2 --text "- Checking default runlevel..." --result "runlevel 3" --color GREEN
                        report "linux_default_runlevel=3"
                    fi
                fi
              else
                logtext "Result: No readlink binary, can't determine where symlink is pointing to"
                Display --indent 2 --text "- Checking default run level" --result UNKNOWN --color YELLOW
            fi
          else
            logtext "Result: no systemd found, so trying inittab"
            logtext "Test: Checking /etc/inittab"
            if [ -f /etc/inittab ]; then
                logtext "Result: file /etc/inittab found"
                logtext "Test: Checking default Linux run level..."
                FIND=`awk -F: '/^id/ { print $2; }' /etc/inittab | head -n 1`
                if [ "${FIND}" = "" ]; then
                    Display --indent 2 --text "- Checking default runlevel" --result UNKNOWN --color YELLOW
                    logtext "Result: Can't determine default run level from /etc/inittab"
                  else
                    Display --indent 2 --text "- Checking default run level..." --result "${FIND}" --color GREEN
                    logtext "Found default run level '${FIND}'"
                    report "linux_default_runlevel=${FIND}"
                fi
              else
                logtext "Result: file /etc/inittab not found"
                if [ "${LINUX_VERSION}" = "Debian" -o "${LINUX_VERSION}" = "Ubuntu" ]; then
                    logtext "Test: Checking run level with who -r, for Debian based systems"
                    FIND=`who -r | awk '{ if ($1=="run-level") { print $2 } }'`
                    if [ ! "${FIND}" = "" ]; then
                        logtext "Result: Found default run level '${FIND}'"
    	                report "linux_default_runlevel=${FIND}"
    	                Display --indent 2 --text "- Checking default run level..." --result "RUNLEVEL ${FIND}" --color GREEN
    	              else
    	                logtext "Result: Can't determine default run level from who -r"
    	                Display --indent 2 --text "- Checking default run level..." --result UNKNOWN --color YELLOW
    	            fi
    	        fi
    	    fi
        fi
    fi 
#
#################################################################################
#

    # Test        : KRNL-5677
    # Description : Check CPU options and support (PAE, No eXecute, eXecute Disable)
    # More info   : pae and nx bit are both visible on AMD and Intel CPU's if supported
    Register --test-no KRNL-5677 --os Linux --weight L --network NO --description "Check CPU options and support"
    if [ ${SKIPTEST} -eq 0 ]; then
        Display --indent 2 --text "- Checking CPU support (NX/PAE)"
        logtext "Test: Checking /proc/cpuinfo..."
        if [ -f /proc/cpuinfo ]; then
            logtext "Result: found /proc/cpuinfo"
            logtext "Test: Checking CPU options (XD/NX/PAE)..."
            FIND_PAE_NX=`cat /proc/cpuinfo | grep " pae " | grep " nx "`
            FIND_PAE=`cat /proc/cpuinfo | grep " pae "`
            FIND_NX=`cat /proc/cpuinfo | grep " nx "`
            FOUND=0
            if [ ! "${FIND_PAE_NX}" = "" ]; then
                logtext "PAE: Yes"
                logtext "NX: Yes"
                CPU_PAE=1
                CPU_NX=1
                logtext "Result: PAE or No eXecute option(s) both found"
                report "cpu_pae=1"
                report "cpu_nx=1"
                FOUND=1
              else
                if [ ! "${FIND_PAE}" = "" -a "${FIND_NX}" = "" ]; then
                    report "cpu_pae=1"
                    logtext "Result: found PAE"
                    CPU_PAE=1
                    FOUND=1
                  else
                    if [ ! "${FIND_NX}" = "" -a "${FIND_PAE}" = "" ]; then
                        report "cpu_nx=1"
                        logtext "Result: found No eXecute"
                        CPU_NX=1
                        FOUND=1
                      else
                        logtext "Result: found no CPU options enabled (PAE or NX bit)"
                    fi
                fi
            fi
            if [ ${FOUND} -eq 1 ]; then
                Display --indent 4 --text "CPU support: PAE and/or NoeXecute supported" --result FOUND --color GREEN
              else
                Display --indent 4 --text "CPU support: No PAE or NoeXecute supported" --result NONE --color YELLOW
                ReportSuggestion ${TEST_NO} "Use a PAE enabled kernel when possible to gain native No eXecute/eXecute Disable support"
            fi
          else
            Display --indent 4 --text "CPU support: no /proc/cpuinfo" --result SKIPPED --color YELLOW
            logtext "Result: /proc/cpuinfo not found"
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5680
    # Description : Check if installed kernel has PAE support
    # Dependency  : KRNL-5677
    # More info   : RedHat/CentOS/Fedora uses the package name 'kernel-PAE'
#
#################################################################################
#
    # Test        : KRNL-5695
    # Description : Determining Linux kernel version and release number
    Register --test-no KRNL-5695 --os Linux --weight L --network NO --description "Determine Linux kernel version and release number"
    if [ ${SKIPTEST} -eq 0 ]; then
        # Kernel number (and suffix)
        LINUX_KERNEL_RELEASE=`uname -r`
        report "linux_kernel_release=${LINUX_KERNEL_RELEASE}"
        logtext "Result: found kernel release ${LINUX_KERNEL_RELEASE}"
        # Type and build date
        LINUX_KERNEL_VERSION=`uname -v`
        report "linux_kernel_version=${LINUX_KERNEL_VERSION}"
        logtext "Result: found kernel version ${LINUX_KERNEL_VERSION}"
        Display --indent 2 --text "- Checking kernel version and release" --result DONE --color GREEN
    fi
#
#################################################################################
#
    # Test        : KRNL-5723
    # Description : Check if Linux is build as a monolithic kernel or not
    Register --test-no KRNL-5723 --os Linux --weight L --network NO --description "Determining if Linux kernel is monolithic"
    if [ ${SKIPTEST} -eq 0 ]; then
        if [ ! "${LSMODBINARY}" = "" ]; then
            logtext "Test: checking if kernel is monolithic or modular"
            # Checking if any modules are loaded
            FIND=`${LSMODBINARY} | grep -v "^Module" | wc -l | tr -s ' ' | tr -d ' '`
            Display --indent 2 --text "- Checking kernel type" --result DONE --color GREEN
            if [ "${FIND}" = "0" ]; then
                logtext "Result: Found monolithic kernel"
                report "linux_kernel_type=monolithic"
                MONOLITHIC_KERNEL=1
              else
                logtext "Result: Found modular kernel"
                report "linux_kernel_type=modular"
                MONOLITHIC_KERNEL=0
            fi
          else
            logtext "Test skipped, no lsmod binary found"
            # Exception?
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5726
    # Description : Checking Linux loaded kernel modules
    Register --test-no KRNL-5726 --os Linux --weight L --network NO --description "Checking Linux loaded kernel modules"
    if [ ${SKIPTEST} -eq 0 ]; then
        if [ ! "${LSMODBINARY}" = "" ]; then
            FIND=`lsmod | awk '{ if ($1!="Module") print $1 }' | sort`
            Display --indent 2 --text "- Checking loaded kernel modules" --result DONE --color GREEN
            if [ ! "${FIND}" = "" ]; then
                logtext "Loaded modules according lsmod:"
                N=0
                for I in ${FIND}; do
                        logtext "Loaded module: ${I}"
                        report "loaded_kernel_module[]=${I}"
                        N=`expr ${N} + 1`
                done
                Display --indent 6 --text "Found ${N} active modules"
              else
                logtext "Result: no loaded modules found"
                logtext "Notice: No loaded kernel modules could indicate a broken/malformed lsmod, or a (custom) monolithic kernel"
            fi
          else
            logtext "Test skipped, no lsmod binary found"
            # Exception?
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5728
    # Description : Checking for available Linux kernel configuration file in /boot
    Register --test-no KRNL-5728 --os Linux --weight L --network NO --description "Checking Linux kernel config"
    if [ ${SKIPTEST} -eq 0 ]; then
        LINUXCONFIGFILE="/boot/config-`uname -r`"
        if [ -f ${LINUXCONFIGFILE} ]; then
            logtext "Result: found config (${LINUXCONFIGFILE})"
            Display --indent 2 --text "- Checking Linux kernel configuration file" --result FOUND --color GREEN
          else
            logtext "Result: no Linux kernel configuration file found in /boot"
            Display --indent 2 --text "- Checking Linux kernel configuration file" --result "NOT FOUND" --color WHITE
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5730
    # Description : Checking default I/O kernel scheduler
    PREQS_MET="NO"
    if [ ! "${LINUXCONFIGFILE}" = "" ]; then
        if [ -f ${LINUXCONFIGFILE} ]; then PREQS_MET="YES"; fi
    fi
    Register --test-no KRNL-5730 --os Linux --preqs-met ${PREQS_MET} --weight L --network NO --description "Checking disk I/O kernel scheduler"
    if [ ${SKIPTEST} -eq 0 ]; then
        logtext "Test: Checking the default I/O kernel scheduler"
        LINUX_KERNEL_IOSCHED=`${GREPBINARY} "CONFIG_DEFAULT_IOSCHED" ${LINUXCONFIGFILE} | awk -F= '{ print $2 }' | sed s/\"//g`
        if [ ! "${LINUX_KERNEL_IOSCHED}" = "" ]; then
            logtext "Result: found [${LINUX_KERNEL_IOSCHED}]"
            Display --indent 2 --text "- Checking default I/O kernel scheduler" --result FOUND --color GREEN
            report "linux_kernel_io_scheduler[]=${LINUX_KERNEL_IOSCHED}"
          else
            logtext "Result: no default i/o kernel scheduler found"
            Display --indent 2 --text "- Checking default I/O kernel scheduler" --result "NOT FOUND" --color WHITE
        fi
   fi
#
#################################################################################
#
# YYY Check for kernel options
#
#################################################################################
#
    # Test        : KRNL-5745
    # Description : Checking FreeBSD loaded kernel modules
    Register --test-no KRNL-5745 --os FreeBSD --weight L --network NO --description "Checking FreeBSD loaded kernel modules"
    if [ ${SKIPTEST} -eq 0 ]; then
        Display --indent 2 --text "- Checking active kernel modules..."
        logtext "Test: ${KERNEL_ACTIVE_MODULES_TITLE}"
        logtext "Description: ${KERNEL_ACTIVE_MODULES_DESCRIPTION}"
        logtext "Action: Checking modules"
        if [ -f /sbin/kldstat ]; then
            FIND=`kldstat | grep -v 'Name' | tr -s ' ' | cut -d ' ' -f6`
            if [ $? -eq 0 ]; then
                logtext "Loaded modules according kldstat:"
                N=0
                for I in ${FIND}; do
                    logtext "Loaded module: ${I}"
                    report "loaded_kernel_module[]=${I}"
                    N=`expr ${N} + 1`
                done
                Display --indent 4 --text "Found ${N} kernel modules" --result DONE --color GREEN
              else
                Display --indent 4 --text "Test failed" --result WARNING --color RED
                logtext "Result: Problem with executing kldstat"
            fi
          else
            echo "[ ${WHITE}SKIPPED${NORMAL} ]"
            logtext "Result: no results, can't find /sbin/kldstat"
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5770
    # Description : Checking Solaris load modules
    Register --test-no KRNL-5770 --os Solaris --weight L --network NO --description "Checking active kernel modules"
    if [ ${SKIPTEST} -eq 0 ]; then
        logtext "Test: searching loaded kernel modules"
        FIND=`modinfo -c -w | grep -v "UNLOADED" | grep LOADED | awk '{ print $3 }' | sort`
        if [ ! "${FIND}" = "" ]; then
            for I in ${FIND}; do
                logtext "Found module: ${I}"
                report "loaded_kernel_module[]=${I}"
            done
            Display --indent 2 --text "- Checking Solaris active kernel modules" --result DONE --color GREEN
          else
            logtext "Result: no output"
            Display --indent 2 --text "- Checking Solaris active kernel modules" --result UNKNOWN --color YELLOW
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5788
    # Description : Checking availability new kernel
    if [ "${LINUX_VERSION}" = "Debian" -o "${LINUX_VERSION}" = "Ubuntu" ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi
    Register --test-no KRNL-5788 --os Linux --preqs-met ${PREQS_MET} --weight L --network NO --description "Checking availability new Linux kernel"
    if [ ${SKIPTEST} -eq 0 ]; then
        logtext "Test: Searching apt-cache, to determine if a newer kernel is available"
        if [ -x /usr/bin/apt-cache ]; then
            logtext "Result: found /usr/bin/apt-cache"
            # YYY Test for presence /usr/bin/apt-cache and dpkg
            logtext "Test: checking readlink location of /vmlinuz"
            FINDKERNFILE=`readlink -f /vmlinuz`
            logtext "Output: readlink reported file ${FINDKERNFILE}"
            logtext "Test: checking package from dpkg -S"
            FINDKERNEL=`dpkg -S ${FINDKERNFILE} 2> /dev/null | awk -F : '{print $1}'`
            logtext "Output: dpkg -S reported package ${FINDKERNEL}"
            logtext "Test: Using apt-cache policy to determine if there is an update available"
            FINDINST=`apt-cache policy ${FINDKERNEL} | egrep 'Installed' | cut -d ':' -f2 | tr -d ' '`
            FINDCAND=`apt-cache policy ${FINDKERNEL} | egrep 'Candidate' | cut -d ':' -f2 | tr -d ' '`
            logtext "Kernel installed: ${FINDINST}"
            logtext "Kernel candidate: ${FINDCAND}"
            if [ "${FINDINST}" = "" ]; then
                Display --indent 2 --text "- Checking for available kernel update... " --result UNKNOWN --color YELLOW
                logtext "Result: Exception occured, no output from apt-cache policy"
                ReportException "${TEST_NO}:01"
                logtext "Exception: apt-cache policy did not return an installed kernel version"
                ReportSuggestion ${TEST_NO} "Check the output of apt-cache policy manually to determine why output is empty"
              else
                if [ "${FINDINST}" = "${FINDCAND}" ]; then
                    Display --indent 2 --text "- Checking for available kernel update... " --result OK --color GREEN
                    logtext "Result: no kernel update available"
                  else
                    Display --indent 2 --text "- Checking for available kernel update... " --result "UPDATE AVAILABLE" --color YELLOW
                    logtext "Result: kernel update available according 'apt-cache policy'."
                    ReportSuggestion ${TEST_NO} "Determine priority for available kernel update"
                fi
            fi
          else
            logtext "Result: could NOT find /usr/bin/apt-cache, skipped other tests."
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5820
    # Description : Checking core dumps configuration (Linux)
    Register --test-no KRNL-5820 --os Linux --weight L --network NO --description "Checking core dumps configuration"
    if [ ${SKIPTEST} -eq 0 ]; then
        logtext "Test: Checking presence /etc/security/limits.conf"
        if [ -f /etc/security/limits.conf ]; then
            logtext "Result: file /etc/security/limits.conf exists" 
            logtext "Test: Checking if core dumps are disabled in /etc/security/limits.conf"
            FIND1=`cat /etc/security/limits.conf | grep -v "^#" | grep -v "^$" | awk '{ if ($1=="*" && $2=="soft" && $3=="core") { print "soft core enabled" } }'`
            FIND2=`cat /etc/security/limits.conf | grep -v "^#" | grep -v "^$" | awk '{ if ($1=="*" && $2=="hard" && $3=="core") { print "hard core enabled" } }'`
            if [ "${FIND1}" = "soft core enabled" -o "${FIND2}" = "hard core enabled" ]; then
                logtext "Result: core dumps (soft or hard) are enabled"
                Display --indent 2 --text "- Checking core dumps configuration... " --result ENABLED --color YELLOW
                #YYY suggestion
                AddHP 1 2
              else
                logtext "Result: core dumps (soft and hard) are both disabled"
                Display --indent 2 --text "- Checking core dumps configuration... " --result DISABLED --color GREEN
                CORE_DUMPS_DISABLED=1
                AddHP 3 3
            fi

            # Sysctl option
            logtext "Test: Checking sysctl value of fs.suid_dumpable"
            FIND=`${SYSCTLBINARY} fs.suid_dumpable 2> /dev/null | awk '{ if ($1=="fs.suid_dumpable") { print $3 } }'`
            if [ "${FIND}" = "" ]; then
                logtext "Result: value ${FIND} found"
              else
                logtext "Result: sysctl key fs.suid_dumpable not found"
            fi
            if [ "${FIND}" = "2" ]; then
                logtext "Result: programs can dump core dump, but only readable by root (value 2, for debugging with file protection)"
                Display --indent 4 --text "- Checking setuid core dumps configuration... " --result PROTECTED --color GREEN
                AddHP 1 1
            elif [ "${FIND}" = "1" ]; then
                logtext "Result: all programs can perform core dumps (value 1, for debugging)"
                Display --indent 2 --text "- Checking setuid core dumps configuration... " --result DEBUG --color YELLOW
                ReportSuggestion ${TEST_NO} "Determine if really all binaries need to be able to core dump"
                AddHP 0 1
              else
                logtext "Result: found default option, some programs can dump (not processes which need to change credentials)"
                Display --indent 4 --text "- Checking setuid core dumps configuration... " --result DEFAULT --color YELLOW
                AddHP 1 1
            fi
            # Check ulimit settings and harden it
            # echo 'ulimit -S -c 0 > /dev/null 2>&1' >> /etc/profile
          else
            logtext "Result: file /etc/security/limits.conf does not exist, skipping test" 
        fi
    fi
#
#################################################################################
#
    # Test        : KRNL-5826
    # Description : Checking core dumps configuration (Solaris)
    #Register --test-no KRNL-5826 --os Linux --weight L --network NO --description "Checking core dumps configuration"
    #if [ ${SKIPTEST} -eq 0 ]; then
#
#################################################################################
#
    # Test        : KRNL-5830
    # Description : Check if system needs a reboot (Debian based)
    Register --test-no KRNL-5830 --weight L --network NO --description "Checking core dumps configuration"
    if [ ${SKIPTEST} -eq 0 ]; then
        FILE="/var/run/reboot-required.pkgs"
        logtext "Test: Checking presence ${FILE}"
        if [ -f ${FILE} ]; then
            logtext "Result: file ${FILE} exists" 
            FIND=`cat ${FILE}`
            if [ "${FIND}" = "" ]; then
                Display --indent 2 --text "- Check if reboot is needed" --result NO --color GREEN
                AddHP 5 5
              else
                PKGSCOUNT=`cat ${FILE} | wc -l`
                Display --indent 2 --text "- Check if reboot is needed" --result YES --color RED
                ReportWarning ${TEST_NO} "H" "Reboot of system is needed"
                logtext "Result: reboot is needed, related to ${PKGSCOUNT} packages"
                for I in ${FIND}; do
                    logtext "Package: ${I}"
                done
                AddHP 0 5
            fi
          else
            logtext "Result: file ${FILE} not found, skipping further testing"
        fi
    fi
#
#################################################################################
#

wait_for_keypress

#
#================================================================================
# Lynis - Copyright 2007-2014, Michael Boelen - http://cisofy.com - The Netherlands