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Diffstat (limited to 'kernels/gradm/policy')
| -rw-r--r-- | kernels/gradm/policy | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/kernels/gradm/policy b/kernels/gradm/policy new file mode 100644 index 000000000..55a5811c8 --- /dev/null +++ b/kernels/gradm/policy @@ -0,0 +1,487 @@ +#sample default policy for grsecurity +# +# Role flags: +# A -> This role is an administrative role, thus it has special privilege normal +# roles do not have. In particular, this role bypasses the +# additional ptrace restrictions +# N -> Don't require authentication for this role. To access +# the role, use gradm -n <rolename> +# s -> This role is a special role, meaning it does not belong to a +# user or group, and does not require an enforced secure policy +# base to be included in the ruleset +# u -> This role is a user role +# g -> This role is a group role +# G -> This role can use gradm to authenticate to the kernel +# A policy for gradm will automatically be added to the role +# T -> Enable TPE for this role +# l -> Enable learning for this role +# P -> Use PAM authentication for this role. +# R -> Enable persistence of special role. Normal special roles will +# be removed upon exit of the process that entered the role, or +# upon unauth (this is what changes the apache process' role back +# to its normal role after being restarted from the admin role, for +# instance). Role persistence allows a special role to be used for +# system shutdown, as the point at which the admin's shell/SSH +# session is terminated won't cause the rest of the shutdown +# sequence to execute with reduced privilege. Do *NOT* use this +# flag with any role that does anything but shut the system down. +# This role will also be transferred to the init process upon +# writing to /dev/initctl. This allows init to execute the rc +# scripts for shutdown with the necessary privilege. +# For usability reasons, we allow the removal of persistence through +# the normal unauth process (so persistence only survives exit). +# +# a role can only be one of user, group, or special +# +# role_allow_ip IP/optional netmask +# eg: role_allow_ip 192.168.1.0/24 +# You can have as many of these per role as you want +# They restrict the use of a role to a list of IPs. If a user +# is on the system that would normally get the role does not +# belong to those lists of IPs, the system falls back through +# its method of determining a role for the user +# +# Role hierarchy +# user -> group -> default +# First a user role attempts to match, if one is not found, +# a group role attempts to match, if one is not found, +# the default role is used. +# +# role_transitions <special role 1> <special role 2> ... <special role n> +# eg: role_transitions www_admin dns_admin +# +# role transitions specify which special roles a given role is allowed +# to authenticate to. This applies to special roles that do not +# require password authentication as well. If a user tries to +# authenticate to a role that is not within his transition table, he +# will receive a permission denied error +# +# Nested subjects +# subject /bin/su:/bin/bash:/bin/cat +# / rwx +# +CAP_ALL +# grant privilege to specific processes if they are executed +# within a trusted path. In this case, privilege is +# granted if /bin/cat is executed from /bin/bash, which is +# executed from /bin/su. +# +# Configuration inheritance on nested subjects +# nested subjects inherit rules from their parents. In the +# example above, the nested subject would inherit rules +# from the nested subject for /bin/su:/bin/bash, +# and the subject /bin/su +# View the 1.9.x documentation for more information on +# configuration inheritance +# +# new object modes: +# m -> allow creation of setuid/setgid files/directories +# and modification of files/directories to be setuid/setgid +# M -> audit the setuid/setgid creation/modification +# c -> allow creation of the file/directory +# C -> audit the creation +# d -> allow deletion of the file/directory +# D -> audit the deletion +# p -> reject all ptraces to this object +# l -> allow a hardlink at this path +# (hardlinking requires at a minimum c and l modes, and the target +# link cannot have any greater permission than the source file) +# L -> audit link creation +# f -> needed to mark the pipe used for communication with init +# to transfer the privilege of the persistent role; only valid +# within a persistent role. Transfer only occurs when the file is +# opened for writing +# +# new subject modes: +# O -> disable "writable library" restrictions for this task +# t -> allow this process to ptrace any process (use with caution) +# r -> relax ptrace restrictions (allows process to ptrace processes +# other than its own descendants) +# i -> enable inheritance-based learning for this subject, causing +# all accesses of this subject and anything it executes to be placed +# in this subject, and inheritance flags added to executable objects +# in this subject +# a -> allow this process to talk to the /dev/grsec device +# s -> enable AT_SECURE when entering this subject +# (enables the same environment sanitization that occurs in glibc +# upon execution of a suid binary) +# x -> allows executable anonymous shared memory for this subject +# +# user/group transitions: +# You may now specify what users and groups a given subject can +# transition to. This can be done on an inclusive or exclusive basis. +# Omitting these rules allows a process with proper privilege granted by +# capabilities to transition to any user/group. +# +# Examples: +# subject /bin/su +# user_transition_allow root spender +# group_transition_allow root spender +# subject /bin/su +# user_transition_deny evilhacker +# subject /bin/su +# group_transition_deny evilhacker1 evilhacker2 +# +# Domains: +# With domains you can combine users that don't share a common +# GID as well as groups so that they share a single policy +# Domains work just like roles, with the only exception being that +# the line starting with "role" is replaced with one of the following: +# domain somedomainname u user1 user2 user3 user4 ... usern +# domain somedomainname g group1 group2 group3 group4 ... groupn +# +# Inverted socket policies: +# Rules such as +# connect ! www.google.com:80 stream tcp +# are now allowed, which allows you to specify that a process can connect to anything +# except to port 80 of www.google.com with a stream tcp socket +# the inverted socket matching also works on bind rules +# +# INADDR_ANY overriding +# You can now force a given subject to bind to a particular IP address on the machine +# This is useful for some chrooted environments, to ensure that the source IP they +# use is one of your choosing +# to use, add a line like: +# ip_override 192.168.0.1 +# +# Per-interface socket policies: +# Rules such as +# bind eth1:80 stream tcp +# bind eth0#1:22 stream tcp +# are now allowed, giving you the ability to tie specific socket rules +# to a single interface (or by using the inverted rules, all but one +# interface). Virtual interfaces are specified by the <ifname>#<vindex> +# syntax. If an interface is specified, no IP/netmask or host may be +# specified for the rule. +# +# Allowing additional socket families: +# Before v2.2.1 of the RBAC system, a subject that specified +# connect/bind rules limited only the socket usage of IPv4, allowing +# any other socket families to be used. Starting with v2.2.1 of the +# RBAC system, when connect/bind rules are used, additional rules +# will be required to unlock the use of additional socket families +# (outside of the common unix family). Multiple families can be +# specified per line. +# To enable use of IPv6, add the line: +# sock_allow_family ipv6 +# To enable use of netlink, add the line: +# sock_allow_family netlink +# To enable all other families, add the line: +# sock_allow_family all +# +# New learning system: +# To learn on a given subject: add l (the letter l, not the number 1) +# to the subject mode +# If you want to learn with the most restrictive policy, use the +# following: +# subject /path/to/bin lo +# / h +# -CAP_ALL +# connect disabled +# bind disabled +# Resource learning is also supported, so lines like +# RES_AS 0 0 +# can be used to learn a particular resource +# +# To learn on a given role, add l to the role mode +# For both of these, to enable learning, enable the system like: +# gradm -L /etc/grsec/learning.logs -E +# and then generate the rules after disabling the system after the +# learning phase with: +# gradm -L /etc/grsec/learning.logs -O /etc/grsec/policy +# To use full system learning, enable the system like: +# gradm -F -L /etc/grsec/learning.logs +# and then generate the rules after disabling the system after the +# learning phase with: +# gradm -F -L /etc/grsec/learning.logs -O /etc/grsec/policy +# +# New PaX flag format (replaces PaX subject flags): +# PaX flags can be forced on or off, regardless of the flags on the +# binary, by using + or - before the following PaX flag names: +# PAX_SEGMEXEC +# PAX_PAGEEXEC +# PAX_MPROTECT +# PAX_RANDMMAP +# PAX_EMUTRAMP +# +# New feature for easier policy maintenance: +# replace <variable name> <replace string> +# e.g.: +# replace CVSROOT /home/cvs +# now $(CVSROOT) can be used in any subject or object pathname, like: +# $(CVSROOT)/grsecurity r +# This will translate to /home/cvs/grsecurity r +# This feature makes it easier to update policies by naming specific +# paths by their function, then only having to update those paths once +# to have it affect a large number of subjects/objects. +# +# capability auditing / log suppression +# use of a capability can be audited by adding "audit" to the line, eg: +# +CAP_SYS_RAWIO audit +# log suppression for denial of a capbility can be done by adding "suppress": +# -CAP_SYS_RAWIO suppress +# +# Per-role umask enforcement: +# If you have a user that you want to be assured cannot accidentally +# create a file that others can read (a confidentiality issue) +# add the following under the role declaration: +# role_umask 077 +# any normal octal umask may be specified +# Note that unlike the normal umask, this umask will also apply +# to the permissions one can chmod/fchmod a file to +# +# Note that the omission of any feature of a role or subject +# results in a default-allow +# For instance, if no capability rules are added, an implicit +CAP_ALL is used +# +# Commonly-used objects can be defined and used in multiple subjects +# As an example, we'll create a variable out of a list of objects +# and their associated permissions that RBAC enforces +define grsec_denied { + /boot h + /dev/grsec h + /dev/kmem h + /dev/mem h + /dev/port h + /etc/grsec h + /proc/kcore h + /proc/slabinfo h + /proc/modules h + /proc/kallsyms h + # hide and suppress logs about accessing this path + /usr/lib/modules hs + /etc/ssh h +} +# usage: +# $grsec_denied + +role shutdown sARG +subject / rvka + / + /dev + /dev/urandom r + /dev/random r + /etc r + /usr rx + /proc r + $grsec_denied + -CAP_ALL + connect disabled + bind disabled + +subject /usr/lib/systemd/systemd rvkao + / rwcdmlxi +subject /usr/bin/systemctl rvkao + / rwcdmlxi + /dev/initctl rwf + /run/initctl rwf + +# Make sure to unauthenticate with gradm -u from +# the admin role after restarting a service +# The service started will run with admin +# privileges until you run gradm -u or your shell exits + +role admin sA +subject / rvka + / rwcdmlxi + +role default G +role_transitions admin shutdown +subject / + / r + /opt rx + /home rwxcd + /mnt rw + /dev + /dev/urandom r + /dev/random r + /dev/zero rw + /dev/input rw + /dev/psaux rw + /dev/null rw + /dev/tty? rw + /dev/console rw + /dev/tty rw + /dev/pts rw + /dev/ptmx rw + /dev/dsp rw + /dev/mixer rw + /dev/initctl rw + /dev/fd0 r + /dev/cdrom r + /usr rx +# compilation of kernel code should be done within the admin role + /usr/src h + /etc rx + /proc rwx + /proc/sys r + /sys h + /root r + /run r + /tmp rwcd + /var rwxcd + /var/tmp rwcd + /var/log r +# hide the kernel images and modules + $grsec_denied + +# if sshd needs to be restarted, it can be done through the admin role +# restarting sshd should be followed immediately by a gradm -u + /usr/sbin/sshd + + /home/*/.gem/ruby/2.0.0/bin rx + /home/*/.rbenv/shims rx + /home/*/.rbenv/versions*/bin rx + /home/*/.cabal/bin rx + /home/*/dev/env rx + + -CAP_KILL + -CAP_SYS_TTY_CONFIG + -CAP_LINUX_IMMUTABLE + -CAP_NET_RAW + -CAP_MKNOD + -CAP_SYS_ADMIN + -CAP_SYS_RAWIO + -CAP_SYS_MODULE + -CAP_SYS_PTRACE + -CAP_NET_ADMIN + -CAP_NET_BIND_SERVICE + -CAP_NET_RAW + -CAP_SYS_CHROOT + -CAP_SYS_BOOT + -CAP_SETFCAP + -CAP_SYSLOG + +# RES_AS 100M 100M + +# connect 192.168.1.0/24:22 stream tcp +# bind 0.0.0.0 stream dgram tcp udp + +# the d flag protects /proc fd and mem entries for sshd +# all daemons should have 'p' in their subject mode to prevent +# an attacker from killing the service (and restarting it with trojaned +# config file or taking the port it reserved to run a trojaned service) + +subject /usr/sbin/sshd dpo + / + /* h + /bin/bash x + /dev h + /dev/log rw + /dev/random r + /dev/urandom r + /dev/null rw + /dev/ptmx rw + /dev/pts rw + /dev/tty rw + /dev/tty? rw + /etc r + /etc/grsec h + /home + /home/*/.ssh/authorized_keys r + /root + /proc r + /proc/*/oom_adj rw + /proc/kcore h + /proc/sys h + /proc/sys/kernel/ngroups_max r + /selinux r + /usr/lib rx + /usr/share/zoneinfo r + /var/log + /var/mail + /var/log/lastlog rw + /var/log/wtmp w + /var/run + /run + /var/run/sshd + /var/run/utmp rw + /var/run/utmpx rw + /var/run/.nscd_socket rw + + -CAP_ALL + +CAP_CHOWN + +CAP_SETGID + +CAP_SETUID + +CAP_SYS_CHROOT + +CAP_SYS_RESOURCE + +CAP_SYS_TTY_CONFIG + +CAP_AUDIT_WRITE + # to access user keys + +CAP_DAC_OVERRIDE + +subject /usr/bin/Xorg + /dev/mem rw + + +CAP_SYS_ADMIN + +CAP_SYS_TTY_CONFIG + +CAP_SYS_RAWIO + +subject /usr/bin/ssh + /etc/ssh/ssh_config r + +subject /usr/bin/postgres + /dev/log rw + +subject /usr/bin/exim + /dev/log rw + +subject /usr/sbin/syslog-ng + +CAP_SYS_ADMIN + +subject /usr/sbin/rsyslogd + +CAP_SYS_ADMIN + +subject /usr/sbin/cron + /dev/log rw + +subject /usr/sbin/crond + /dev/log rw + +subject /bin/login + /dev/log rw + /var/log/wtmp w + /var/log/faillog rwcd + +subject /bin/su + /dev/log rw + +subject /usr/bin/sudo + /dev/log rw + +subject /sbin/agetty + /var/log/wtmp w + +subject /sbin/init + /var/log/wtmp w + +subject /usr/bin/xauth + /home r + /home/*/.Xauthority-* rwcdl + +# prevent ld.so breakouts of subjects with /lib rx + +# many distros clutter up /lib with shell scripts +# that can be easily hijacked for malicious purposes +subject /usr/lib o + / h + -CAP_ALL + connect disabled + bind disabled + +subject /usr/lib32 o + / h + -CAP_ALL + connect disabled + bind disabled + +subject /usr/lib/ld-linux.so.2 o + / h + -CAP_ALL + connect disabled + bind disabled + +subject /usr/lib/ld-linux-x86-64.so.2 o + / h + -CAP_ALL + connect disabled + bind disabled |