improve remount-secure

This commit is contained in:
Patrick Schleizer 2023-10-22 12:54:25 -04:00
parent 1696c37251
commit 84ca0ac8a0
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GPG Key ID: CB8D50BB77BB3C48
2 changed files with 59 additions and 15 deletions

View File

@ -6,6 +6,7 @@
## noexec in /tmp and/or /home can break some malware but also legitimate
## applications.
## https://www.kicksecure.com/wiki/Dev/remount-secure
## https://forums.whonix.org/t/re-mount-home-and-other-with-noexec-and-nosuid-among-other-useful-mount-options-for-better-security/7707
#set -x
@ -29,10 +30,26 @@ init() {
mkdir --parents "/run/remount-secure"
exit_code=0
## dracut sets NEWROOT=/sysroot
[[ -v NEWROOT ]] || NEWROOT=""
if [ "$NEWROOT" = "" ]; then
$output_command "INFO: dracut detected: yes - NEWROOT: '$NEWROOT'"
else
$output_command "INFO: dracut detected: yes - NEWROOT: '$NEWROOT'"
fi
## Debugging.
$output_command "INFO: 'findmnt --list' output at the START."
$output_command "$(findmnt --list)"
$output_command ""
## Debugging.
#echo "ls -la /root/"
#ls -la / || true
#echo "ls -la /sysroot/"
#ls -la /sysroot/ || true
#echo "env"
#env || true
}
parse_options() {
@ -103,21 +120,19 @@ remount_secure() {
fi
fi
if ! test -d "$mount_folder" ; then
$output_command "INFO: '$mount_folder' folder exists: no"
exit_code=102
return 0
fi
$output_command "INFO: '$mount_folder' folder exists: yes"
if findmnt --noheadings "$mount_folder" >/dev/null ; then
$output_command "INFO: '$mount_folder' already mounted, therefore using remount."
$output_command INFO: Executing: mount --options "remount,${intended_mount_options}" "$mount_folder"
mount --options "remount,${intended_mount_options}" "$mount_folder" || exit_code=100
else
$output_command "INFO: '$mount_folder' not yet mounted, therefore using mount bind."
## Debugging.
ls "$mount_folder" /x >/dev/null || true
if test -d "$mount_folder" ; then
$output_command "INFO: '$mount_folder' folder exists: yes"
else
$output_command "INFO: '$mount_folder' folder exists: no"
fi
$output_command INFO: Executing: mount --options "$intended_mount_options" --bind "$mount_folder" "$mount_folder"
mount --options "$intended_mount_options" --bind "$mount_folder" "$mount_folder" || exit_code=101
fi
@ -128,35 +143,62 @@ remount_secure() {
touch "$status_file_full_path"
}
_run() {
mount_folder="/run"
_boot() {
mount_folder="$NEWROOT/boot"
## https://lists.freedesktop.org/archives/systemd-devel/2015-February/028456.html
intended_mount_options="nosuid,nodev${noexec_maybe}"
remount_secure "$@"
}
_run() {
mount_folder="$NEWROOT/run"
## https://lists.freedesktop.org/archives/systemd-devel/2015-February/028456.html
intended_mount_options="nosuid,nodev${noexec_maybe}"
remount_secure "$@"
}
## TODO
# _dev() {
# mount_folder="$NEWROOT/dev"
# intended_mount_options="nosuid,${noexec_maybe}"
# remount_secure "$@"
# }
_dev_shm() {
mount_folder="/dev/shm"
mount_folder="$NEWROOT/dev/shm"
intended_mount_options="nosuid,nodev${noexec_maybe}"
remount_secure "$@"
}
_tmp() {
mount_folder="/tmp"
mount_folder="$NEWROOT/tmp"
intended_mount_options="nosuid,nodev${noexec_maybe}"
remount_secure "$@"
}
_var() {
mount_folder="$NEWROOT/var"
## TODO: nodev? noexec?
intended_mount_options="nosuid"
remount_secure "$@"
}
_var_tmp() {
mount_folder="$NEWROOT/var/tmp"
intended_mount_options="nosuid,nodev${noexec_maybe}"
remount_secure "$@"
}
## https://forums.whonix.org/t/re-mount-home-and-other-with-noexec-and-nosuid-among-other-useful-mount-options-for-better-security/7707/25
# _lib() {
# mount_folder="/lib"
# mount_folder="$NEWROOT/lib"
# ## Not using noexec on /lib.
# intended_mount_options="nosuid,nodev"
# remount_secure "$@"
# }
_home() {
mount_folder="/home"
mount_folder="$NEWROOT/home"
intended_mount_options="nosuid,nodev${noexec_maybe}"
remount_secure "$@"
}

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@ -9,6 +9,7 @@ check() {
require_binaries touch || return 1
require_binaries grep || return 1
require_binaries id || return 1
require_binaries env || return 1
require_binaries mount || return 1
require_binaries remount-secure || return 1
return 0
@ -25,6 +26,7 @@ install() {
inst_multiple touch
inst_multiple grep
inst_multiple id
inst_multiple env
inst_multiple mount
inst_multiple remount-secure
inst_hook cleanup 90 "$moddir/remount-secure.sh"