commit: 4ca347319929cb5a24faf7eb587cabda640f28bd Author: Krzysztof Nowicki <krissn <AT> op <DOT> pl> AuthorDate: Thu Aug 13 06:44:22 2020 +0000 Commit: Jason Zaman <perfinion <AT> gentoo <DOT> org> CommitDate: Mon Feb 15 19:49:24 2021 +0000 URL: https://gitweb.gentoo.org/proj/hardened-refpolicy.git/commit/?id=4ca34731
Allow use of systemd UNIX sockets created at initrd execution Systemd uses a number of UNIX sockets for communication (notify socket [1], journald socket). These sockets are normally created at start-up after the SELinux policy is loaded, which means that the kernel socket objects have proper security contexts of the creating processes. Unfortunately things look different when the system is started with an initrd that is also running systemd (e.g. dracut). In such case the sockets are created in the initrd systemd environment before the SELinux policy is loaded and therefore the socket object is assigned the default kernel context (system_u:system_r:kernel_t). When the initrd systemd transfers control to the main systemd the notify socket descriptors are passed to the main systemd process [2]. This means that when the main system is running the sockets will use the default kernel securint context until they are recreated, which for some sockets (notify socket) never happens. Until there is a way to change the context of an already open socket object all processes, that wish to use systemd sockets need to be able to send datagrams to system_u:system_r:kernel_t sockets. Parts of this workaround were earlier hidden behind RedHat-specific rules, since this distribution is the prime user of systemd+dracut combo. Since other distros may want to use similar configuration it makes sense to enable this globally. [1] sd_notify(3) [2] https://github.com/systemd/systemd/issues/16714 Signed-off-by: Krzysztof Nowicki <krissn <AT> op.pl> tmp Signed-off-by: Jason Zaman <perfinion <AT> gentoo.org> policy/modules/kernel/kernel.if | 18 ++++++++++++++++++ policy/modules/system/init.te | 5 +++++ policy/modules/system/logging.if | 5 ++--- policy/modules/system/logging.te | 7 ++++--- 4 files changed, 29 insertions(+), 6 deletions(-) diff --git a/policy/modules/kernel/kernel.if b/policy/modules/kernel/kernel.if index ebd73aca..18002e67 100644 --- a/policy/modules/kernel/kernel.if +++ b/policy/modules/kernel/kernel.if @@ -365,6 +365,24 @@ interface(`kernel_dgram_send',` allow $1 kernel_t:unix_dgram_socket sendto; ') +######################################## +## <summary> +## Send messages to kernel netlink audit sockets. +## </summary> +## <param name="domain"> +## <summary> +## Domain allowed access. +## </summary> +## </param> +# +interface(`kernel_rw_netlink_audit_sockets',` + gen_require(` + type kernel_t; + ') + + allow $1 kernel_t:netlink_audit_socket { rw_netlink_socket_perms }; +') + ######################################## ## <summary> ## Allows caller to load kernel modules diff --git a/policy/modules/system/init.te b/policy/modules/system/init.te index ba82d84a..f711e535 100644 --- a/policy/modules/system/init.te +++ b/policy/modules/system/init.te @@ -312,6 +312,8 @@ ifdef(`init_systemd',` kernel_setsched(init_t) kernel_link_key(init_t) kernel_rw_unix_sysctls(init_t) + kernel_rw_stream_sockets(init_t) + kernel_rw_unix_dgram_sockets(init_t) # run systemd misc initializations # in the initrc_t domain, as would be @@ -1032,6 +1034,9 @@ ifdef(`init_systemd',` allow initrc_t systemdunit:service reload; allow initrc_t init_script_file_type:service { stop start status reload }; + # Access to notify socket for services with Type=notify + kernel_dgram_send(initrc_t) + # run systemd misc initializations # in the initrc_t domain, as would be # done in traditional sysvinit/upstart. diff --git a/policy/modules/system/logging.if b/policy/modules/system/logging.if index 0f6efef8..e3851303 100644 --- a/policy/modules/system/logging.if +++ b/policy/modules/system/logging.if @@ -681,10 +681,9 @@ interface(`logging_send_syslog_msg',` # Allow systemd-journald to check whether the process died allow syslogd_t $1:process signull; - ifdef(`distro_redhat',` - kernel_dgram_send($1) - ') + kernel_dgram_send($1) ') + ') ######################################## diff --git a/policy/modules/system/logging.te b/policy/modules/system/logging.te index fb0fe124..a6868af0 100644 --- a/policy/modules/system/logging.te +++ b/policy/modules/system/logging.te @@ -501,9 +501,6 @@ auth_use_nsswitch(syslogd_t) init_use_fds(syslogd_t) -# cjp: this doesnt make sense -logging_send_syslog_msg(syslogd_t) - miscfiles_read_localization(syslogd_t) seutil_read_config(syslogd_t) @@ -525,6 +522,7 @@ ifdef(`init_systemd',` kernel_read_ring_buffer(syslogd_t) kernel_rw_stream_sockets(syslogd_t) kernel_rw_unix_dgram_sockets(syslogd_t) + kernel_rw_netlink_audit_sockets(syslogd_t) kernel_use_fds(syslogd_t) dev_read_kmsg(syslogd_t) @@ -544,6 +542,9 @@ ifdef(`init_systemd',` init_read_runtime_symlinks(syslogd_t) init_read_state(syslogd_t) + # needed for systemd-initrd case when syslog socket is unlabelled + logging_send_syslog_msg(syslogd_t) + systemd_manage_journal_files(syslogd_t) udev_read_runtime_files(syslogd_t)
