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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | EXAMPLES | AUTHORS | SEE ALSO | AVAILABILITY | COLOPHON |
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SETPRIV(1) User Commands SETPRIV(1)
setpriv - run a program with different Linux privilege settings
setpriv [options] program [arguments]
Sets or queries various Linux privilege settings that are
inherited across execve(2).
In comparison to su(1) and runuser(1), setpriv neither uses PAM,
nor does it prompt for a password. It is a simple, non-set-user-
ID wrapper around execve(2), and can be used to drop privileges
in the same way as setuidgid(8) from daemontools, chpst(8) from
runit, or similar tools shipped by other service managers.
--clear-groups
Clear supplementary groups.
-d, --dump
Dump the current privilege state. This option can be
specified more than once to show extra, mostly useless,
information. Incompatible with all other options.
--groups group...
Set supplementary groups. The argument is a comma-
separated list of GIDs or names.
--inh-caps (+|-)cap... or --ambient-caps (+|-)cap... or
--bounding-set (+|-)cap...
Set the inheritable capabilities, ambient capabilities or
the capability bounding set. See capabilities(7). The
argument is a comma-separated list of +cap and -cap
entries, which add or remove an entry respectively. cap
can either be a human-readable name as seen in
capabilities(7) without the cap_ prefix or of the format
cap_N, where N is the internal capability index used by
Linux. +all and -all can be used to add or remove all
caps.
The set of capabilities starts out as the current
inheritable set for --inh-caps, the current ambient set
for --ambient-caps and the current bounding set for
--bounding-set.
Note the following restrictions (detailed in
capabilities(7)) regarding modifications to these
capability sets:
* A capability can be added to the inheritable set only if
it is currently present in the bounding set.
* A capability can be added to the ambient set only if it
is currently present in both the permitted and
inheritable sets.
* Notwithstanding the syntax offered by setpriv, the
kernel does not permit capabilities to be added to the
bounding set.
If you drop a capability from the bounding set without
also dropping it from the inheritable set, you are likely
to become confused. Do not do that.
--keep-groups
Preserve supplementary groups. Only useful in conjunction
with --rgid, --egid, or --regid.
--init-groups
Initialize supplementary groups using initgroups(3). Only
useful in conjunction with --ruid or --reuid.
--list-caps
List all known capabilities. This option must be
specified alone.
--no-new-privs
Set the no_new_privs bit. With this bit set, execve(2)
will not grant new privileges. For example, the set-user-
ID and set-group-ID bits as well as file capabilities will
be disabled. (Executing binaries with these bits set will
still work, but they will not gain privileges. Certain
LSMs, especially AppArmor, may result in failures to
execute certain programs.) This bit is inherited by child
processes and cannot be unset. See prctl(2) and
Documentation/prctl/no_new_privs.txt in the Linux kernel
source.
The no_new_privs bit is supported since Linux 3.5.
--rgid gid, --egid gid, --regid gid
Set the real, effective, or both GIDs. The gid argument
can be given as a textual group name.
For safety, you must specify one of --clear-groups,
--groups, --keep-groups, or --init-groups if you set any
primary gid.
--ruid uid, --euid uid, --reuid uid
Set the real, effective, or both UIDs. The uid argument
can be given as a textual login name.
Setting a uid or gid does not change capabilities,
although the exec call at the end might change
capabilities. This means that, if you are root, you
probably want to do something like:
setpriv --reuid=1000 --regid=1000 --inh-caps=-all
--securebits (+|-)securebit...
Set or clear securebits. The argument is a comma-
separated list. The valid securebits are noroot,
noroot_locked, no_setuid_fixup, no_setuid_fixup_locked,
and keep_caps_locked. keep_caps is cleared by execve(2)
and is therefore not allowed.
--pdeathsig keep|clear|<signal>
Keep, clear or set the parent death signal. Some LSMs,
most notably SELinux and AppArmor, clear the signal when
the process' credentials change. Using --pdeathsig keep
will restore the parent death signal after changing
credentials to remedy that situation.
--selinux-label label
Request a particular SELinux transition (using a
transition on exec, not dyntrans). This will fail and
cause setpriv to abort if SELinux is not in use, and the
transition may be ignored or cause execve(2) to fail at
SELinux's whim. (In particular, this is unlikely to work
in conjunction with no_new_privs.) This is similar to
runcon(1).
--apparmor-profile profile
Request a particular AppArmor profile (using a transition
on exec). This will fail and cause setpriv to abort if
AppArmor is not in use, and the transition may be ignored
or cause execve(2) to fail at AppArmor's whim.
--reset-env
Clears all the environment variables except TERM;
initializes the environment variables HOME, SHELL, USER,
LOGNAME according to the user's passwd entry; sets PATH to
/usr/local/bin:/bin:/usr/bin for a regular user and to
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
for root.
The environment variable PATH may be different on systems
where /bin and /sbin are merged into /usr. The
environment variable SHELL defaults to /bin/sh if none is
given in the user's passwd entry.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.
If applying any specified option fails, program will not be run
and setpriv will return with exit status 127.
Be careful with this tool -- it may have unexpected security
consequences. For example, setting no_new_privs and then execing
a program that is SELinux-confined (as this tool would do) may
prevent the SELinux restrictions from taking effect.
If you're looking for behaviour similar to su(1)/runuser(1), or
sudo(8) (without the -g option), try something like:
setpriv --reuid=1000 --regid=1000 --init-groups
If you want to mimic daemontools' setuid(8), try:
setpriv --reuid=1000 --regid=1000 --clear-groups
Andy Lutomirski ⟨luto@amacapital.net⟩
runuser(1), su(1), prctl(2), capabilities(7)
The setpriv command is part of the util-linux package and is
available from Linux Kernel Archive
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.
This page is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found
at ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you
have a bug report for this manual page, send it to
util-linux@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2020-12-18. (At that time, the date of the most recent commit
that was found in the repository was 2020-12-17.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
util-linux July 2014 SETPRIV(1)
Pages that refer to this page: runuser(1), su(1), capabilities(7), credentials(7)
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