core: add SystemCallArchitectures= unit setting to allow disabling of non-native

[elogind.git] / man / systemd.exec.xml

diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index 610c821dc095025117444e72bb5d9cfee1964970..01356e4c459ac9b1b01874cb313331a0f6d3c53e 100644 (file)
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -894,6 +894,24 @@
                                 for details.</para></listitem>
                         </varlistentry>
 
                                 for details.</para></listitem>
                         </varlistentry>
 

+                        <varlistentry>
+                                <term><varname>PrivateDevices=</varname></term>
+
+                                <listitem><para>Takes a boolean
+                                argument. If true, sets up a new /dev
+                                namespace for the executed processes
+                                and only adds API pseudo devices such
+                                as <filename>/dev/null</filename>,
+                                <filename>/dev/zero</filename> or
+                                <filename>/dev/random</filename> to
+                                it, but no physical devices such as
+                                <filename>/dev/sda</filename>. This is
+                                useful to securely turn off physical
+                                device access by the executed
+                                process. Defaults to
+                                false.</para></listitem>
+                        </varlistentry>
+

                         <varlistentry>
                                 <term><varname>MountFlags=</varname></term>
 
                         <varlistentry>
                                 <term><varname>MountFlags=</varname></term>
 


@@ -932,6 +950,23 @@
                                 this service.</para></listitem>
                         </varlistentry>
 
                                 this service.</para></listitem>
                         </varlistentry>
 

+                        <varlistentry>
+                                <term><varname>SELinuxContext=</varname></term>
+
+                                <listitem><para>Set the SELinux
+                                security context of the executed
+                                process. If set, this will override
+                                the automated domain
+                                transition. However, the policy still
+                                needs to autorize the transition. This
+                                directive is ignored if SELinux is
+                                disabled. If prefixed by
+                                <literal>-</literal>, all errors will
+                                be ignored. See
+                                <citerefentry><refentrytitle>setexeccon</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                                for details.</para></listitem>
+                        </varlistentry>
+

                         <varlistentry>
                                 <term><varname>IgnoreSIGPIPE=</varname></term>
 
                         <varlistentry>
                                 <term><varname>IgnoreSIGPIPE=</varname></term>
 


@@ -966,7 +1001,7 @@
                                 list of system call
                                 names. If this setting is used, all
                                 system calls executed by the unit
                                 list of system call
                                 names. If this setting is used, all
                                 system calls executed by the unit

-                                process except for the listed ones
+                                processes except for the listed ones

                                 will result in immediate process
                                 termination with the
                                 <constant>SIGSYS</constant> signal
                                 will result in immediate process
                                 termination with the
                                 <constant>SIGSYS</constant> signal


@@ -994,7 +1029,97 @@
                                 merged. If the empty string is
                                 assigned, the filter is reset, all
                                 prior assignments will have no
                                 merged. If the empty string is
                                 assigned, the filter is reset, all
                                 prior assignments will have no

-                                effect.</para></listitem>
+                                effect.</para>
+
+                                <para>If you specify both types of
+                                this option (i.e. whitelisting and
+                                blacklisting) the first encountered
+                                will take precedence and will dictate
+                                the default action (termination or
+                                approval of a system call). Then the
+                                next occurrences of this option will
+                                add or delete the listed system calls
+                                from the set of the filtered system
+                                calls, depending of its type and the
+                                default action (e.g. You have started
+                                with a whitelisting of
+                                <function>read</function> and
+                                <function>write</function> and right
+                                after it add a blacklisting of
+                                <function>write</function>, then
+                                <function>write</function> will be
+                                removed from the set).
+                                </para></listitem>
+
+                                <para>Note that setting
+                                <varname>SystemCallFilter=</varname>
+                                implies a
+                                <varname>SystemCallArchitectures=</varname>
+                                setting of <literal>native</literal>
+                                (see below), unless that option is
+                                configured otherwise.</para>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallErrorNumber=</varname></term>
+
+                                <listitem><para>Takes an
+                                <literal>errno</literal> error number
+                                name to return when the system call
+                                filter configured with
+                                <varname>SystemCallFilter=</varname>
+                                is triggered, instead of terminating
+                                the process immediately. Takes an
+                                error name such as
+                                <literal>EPERM</literal>,
+                                <literal>EACCES</literal> or
+                                <literal>EUCLEAN</literal>. When this
+                                setting is not used, or when the empty
+                                string is assigned the process will be
+                                terminated immediately when the filter
+                                is triggered.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallArchitectures=</varname></term>
+
+                                <listitem><para>Takes a space
+                                separated list of architecture
+                                identifiers to include in the system
+                                call filter. The known architecture
+                                identifiers are
+                                <literal>x86</literal>,
+                                <literal>x86-64</literal>,
+                                <literal>x32</literal>,
+                                <literal>arm</literal> as well as the
+                                special identifier
+                                <literal>native</literal>. Only system
+                                calls of the specified architectures
+                                will be permitted to processes of this
+                                unit. This is an effective way to
+                                disable compatibility with non-native
+                                architectures for processes, for
+                                example to prohibit execution of 32bit
+                                x86 binaries on 64bit x86-64
+                                systems. The special
+                                <literal>native</literal> identifier
+                                implicitly maps to the native
+                                architecture of the system (or more
+                                strictly: to the architecture the
+                                system manager is compiled for). Note
+                                that setting this option to a
+                                non-empty list implies that
+                                <literal>native</literal> is included
+                                too. By default this option is set to
+                                the empty list, i.e. no architecture
+                                system call filtering is applied. Note
+                                that configuring a system call filter
+                                with
+                                <varname>SystemCallFilter=</varname>
+                                (above) implies a
+                                <literal>native</literal> architecture
+                                list, unless configured
+                                otherwise.</para></listitem>

                         </varlistentry>
 
                 </variablelist>
                         </varlistentry>
 
                 </variablelist>