afl-system-config

#!/bin/sh
test "$1" = "-h" -o "$1" = "-hh" && {
  echo 'afl-system-config by Marc Heuse <mh@mh-sec.de>'
  echo
  echo $0
  echo
  echo afl-system-config has no command line options
  echo
  echo afl-system reconfigures the system to a high performance fuzzing state
  echo WARNING: this reduces the security of the system
  echo
  exit 1
}

DONE=
PLATFORM=`uname -s`
echo This reconfigures the system to have a better fuzzing performance.
if [ '!' "$EUID" = 0 ] && [ '!' `id -u` = 0 ] ; then
	echo "Warning: you need to be root to run this!"
	# we do not exit as other mechanisms exist that allows to do this than
	# being root. let the errors speak for themselves.
fi
if [ "$PLATFORM" = "Linux" ] ; then
{
  sysctl -w kernel.core_uses_pid=0
  # Arch Linux requires core_pattern to be empty :(
  test -e /etc/arch-release && sysctl -w kernel.core_pattern=
  test -e /etc/arch-release || sysctl -w kernel.core_pattern=core
  sysctl -w kernel.randomize_va_space=0
  sysctl -w kernel.sched_child_runs_first=1
  sysctl -w kernel.sched_autogroup_enabled=1
  sysctl -w kernel.sched_migration_cost_ns=50000000
  sysctl -w kernel.sched_latency_ns=250000000
  echo never > /sys/kernel/mm/transparent_hugepage/enabled
  test -e /sys/devices/system/cpu/cpufreq/scaling_governor && echo performance | tee /sys/devices/system/cpu/cpufreq/scaling_governor
  test -e /sys/devices/system/cpu/cpufreq/policy0/scaling_governor && echo performance | tee /sys/devices/system/cpu/cpufreq/policy*/scaling_governor
  test -e /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor && echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
  test -e /sys/devices/system/cpu/intel_pstate/no_turbo && echo 0 > /sys/devices/system/cpu/intel_pstate/no_turbo
  test -e /sys/devices/system/cpu/cpufreq/boost && echo 1 > /sys/devices/system/cpu/cpufreq/boost
  test -e /sys/devices/system/cpu/intel_pstate/max_perf_pct && echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
} > /dev/null
  echo Settings applied.
  dmesg | egrep -q 'nospectre_v2|spectre_v2=off' || {
    echo It is recommended to boot the kernel with lots of security off - if you are running a machine that is in a secured network - so set this:
    echo '  /etc/default/grub:GRUB_CMDLINE_LINUX_DEFAULT="ibpb=off ibrs=off kpti=0 l1tf=off mds=off mitigations=off no_stf_barrier noibpb noibrs nopcid nopti nospec_store_bypass_disable nospectre_v1 nospectre_v2 pcid=off pti=off spec_store_bypass_disable=off spectre_v2=off stf_barrier=off srbds=off noexec=off noexec32=off tsx=on tsx_async_abort=off arm64.nopauth audit=0 hardened_usercopy=off ssbd=force-off"'
  }
  DONE=1
fi
if [ "$PLATFORM" = "FreeBSD" ] ; then
{
  sysctl kern.elf32.aslr.enable=0
  sysctl kern.elf64.aslr.enable=0
} > /dev/null
  echo Settings applied.
  cat <<EOF
In order to suppress core file generation during fuzzing it is recommended to set
me:\\
	:coredumpsize=0:
in the ~/.login_conf file for the user used for fuzzing.
EOF
  echo It is recommended to boot the kernel with lots of security off - if you are running a machine that is in a secured network - so set this:
  echo '  sysctl hw.ibrs_disable=1'
  echo 'Setting kern.pmap.pg_ps_enabled=0 into /boot/loader.conf might be helpful too.'
  DONE=1
fi
if [ "$PLATFORM" = "OpenBSD" ] ; then
  echo
  echo 'System security features cannot be disabled on OpenBSD.'
  DONE=1
fi
if [ "$PLATFORM" = "DragonFly" ] ; then
  #/sbin/sysctl kern.corefile=/dev/null
  #echo Settings applied.
  cat <<EOF
In order to suppress core file generation during fuzzing it is recommended to set
me:\\
	:coredumpsize=0:
in the ~/.login_conf file for the user used for fuzzing.
EOF
  DONE=1
fi
if [ "$PLATFORM" = "NetBSD" ] ; then
{
  #echo It is recommended to enable unprivileged users to set cpu affinity
  #echo to be able to use afl-gotcpu meaningfully.
  /sbin/sysctl -w security.models.extensions.user_set_cpu_affinity=1
} > /dev/null
  echo Settings applied.
  DONE=1
fi
if [ "$PLATFORM" = "Darwin" ] ; then
  sysctl kern.sysv.shmmax=8388608
  sysctl kern.sysv.shmseg=48
  sysctl kern.sysv.shmall=98304
  if [ $(launchctl list 2>/dev/null | grep -q '\.ReportCrash$') ] ; then
    echo We unload the default crash reporter here
    SL=/System/Library; PL=com.apple.ReportCrash
    launchctl unload -w ${SL}/LaunchAgents/${PL}.plist
    sudo launchctl unload -w ${SL}/LaunchDaemons/${PL}.Root.plist
    echo Settings applied.
  fi
  DONE=1
fi
if [ "$PLATFORM" = "Haiku" ] ; then
  DEBUG_SERVER_DIR=~/config/settings/system/debug_server
  [ ! -d ${DEBUG_SERVER_DIR} ] && mkdir -p ${DEBUG_SERVER_DIR}
  SETTINGS=${DEBUG_SERVER_DIR}/settings
  [ -r ${SETTINGS} ] && grep -qE "default_action\s+kill" ${SETTINGS} && { echo "Nothing to do"; } || { \
    echo We change the debug_server default_action from user to silently kill; \
    [ ! -r ${SETTINGS} ] && echo "default_action kill" >${SETTINGS} || { mv ${SETTINGS} s.tmp; sed -e "s/default_action\s\s*user/default_action kill/" s.tmp > ${SETTINGS}; rm s.tmp; }; \
    echo Settings applied.; \
  }
  DONE=1
fi
test -z "$DONE" && echo Error: Unknown platform: $PLATFORM
exit 0