mirror of
https://github.com/Kicksecure/security-misc.git
synced 2025-04-25 06:29:12 -04:00
77 lines
2.5 KiB
Bash
Executable File
77 lines
2.5 KiB
Bash
Executable File
#!/usr/bin/env bash
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## Copyright (C) 2019 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
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## See the file COPYING for copying conditions.
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## This script enforces the maximum ASLR hardening settings for mmap, given the
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## installed Linux config.
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## See also:
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## https://forums.whonix.org/t/automate-mmap-randomisation-to-fix-ppc64el/16514
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set -euo pipefail
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shopt -s failglob
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more_info_link="https://forums.whonix.org/t/automate-mmap-randomisation-to-fix-ppc64el/16514"
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exit_with_error() {
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echo "$0: SEE ALSO:" >&2
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echo "" >&2
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echo "$more_info_link" >&2
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exit 1
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}
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if ! test -d /etc/sysctl.d ; then
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echo "$0: ERROR: Folder /etc/sysctl.d does not exist!" >&2
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exit_with_error
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fi
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if ! test -w /etc/sysctl.d ; then
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echo "$0: ERROR: Folder /etc/sysctl.d not writeable! This script is supposed to be run as root." >&2
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exit_with_error
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fi
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## Defaults in case Linux config detection fails. These are likely to work fine
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## on x86_64, probably not elsewhere.
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BITS_MAX_DEFAULT=32
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COMPAT_BITS_MAX_DEFAULT=16
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## Find the most recently modified Linux config file.
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if compgen -G "/boot/config-*" > /dev/null && CONFIG=$(ls -1 -t /boot/config-* | head -n 1) ; then
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## Find the relevant config options.
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if ! BITS_MAX=$(grep -E '^CONFIG_ARCH_MMAP_RND_BITS_MAX=[0-9]+$' "${CONFIG}" | cut -d "=" -f 2) ; then
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echo "$0: ERROR: Error detecting CONFIG_ARCH_MMAP_RND_BITS_MAXQ Using built-in default." >&2
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BITS_MAX="${BITS_MAX_DEFAULT}"
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fi
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if ! COMPAT_BITS_MAX=$(grep -E '^CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX=[0-9]+$' "${CONFIG}" | cut -d "=" -f 2) ; then
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echo "$0: ERROR: Error detecting CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX! Using built-in default." >&2
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COMPAT_BITS_MAX="${COMPAT_BITS_MAX_DEFAULT}"
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fi
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else
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echo "$0: ERROR: Error detecting Linux config! Using built-in defaults." >&2
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BITS_MAX="${BITS_MAX_DEFAULT}"
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COMPAT_BITS_MAX="${COMPAT_BITS_MAX_DEFAULT}"
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fi
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## Generate a sysctl.d conf file.
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SYSCTL="\
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## Copyright (C) 2019 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
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## See the file COPYING for copying conditions.
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## This file is automatically generated by:
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## $0
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## Do not edit!
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## See also:
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## $more_info_link
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## Improves ASLR effectiveness for mmap.
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vm.mmap_rnd_bits=${BITS_MAX}
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vm.mmap_rnd_compat_bits=${COMPAT_BITS_MAX}"
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## Write the sysctl.d conf file.
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if echo "${SYSCTL}" | tee /etc/sysctl.d/30_security-misc_aslr-mmap.conf > /dev/null ; then
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exit 0
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fi
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echo "$0: ERROR: Error writing ASLR map config file '/etc/sysctl.d/30_security-misc_aslr-mmap.conf'!" >&2
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exit_with_error
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