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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | EXAMPLES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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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..., --ambient-caps (+|-)cap...,
--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 initgroups3. 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.
--landlock-access access
Enable landlock restrictions for a specific set of system
accesses. To allow specific subgroups of accesses use
--landlock-rule.
Block all filesystem access:
setpriv --landlock-access fs
Block all file deletions and directory creations:
setpriv --landlock-access fs:remove-file,make-dir
For a complete set of supported access categories use setpriv
--help.
--landlock-rule rule
Allow one specific access from the categories blocked by
--landlock-access.
The syntax is as follows:
--landlock-rule $ruletype:$access:$rulearg
For example grant file read access to everything under /boot:
--landlock-rule path-beneath:read-file:/boot
--seccomp-filter file
Load raw BPF seccomp filter code from a file.
Filters can for example be created with enosys.
--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.
-h, --help
Display help text and exit.
-V, --version
Print version 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 behavior 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 <[email protected]>
runuser(1), su(1), prctl(2), capabilities(7) landlock(7)
For bug reports, use the issue tracker at
https://github.com/util-linux/util-linux/issues.
The setpriv command is part of the util-linux package which can
be downloaded 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
[email protected]. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) 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 [email protected]
util-linux 2.41.devel-537-e... 2024-04-04 SETPRIV(1)
Pages that refer to this page: runuser(1), su(1), capabilities(7), credentials(7)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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