mirror of
https://github.com/freebsd/freebsd-src.git
synced 2026-10-28 11:25:21 +01:00
Kyle Evans
9da2fe96ff
On most other platforms observed, including OpenBSD, NetBSD, and Linux,
these system calls have long since been converted to only touching the
supplementary groups of the process. This poses both portability and
security concerns in porting software to and from FreeBSD, as this
subtle difference is a landmine waiting to happen. Bugs have been
discovered even in FreeBSD-local sources, since this behavior is
somewhat unintuitive (see, e.g., fix 48fd05999b for chroot(8)).
Now that the egid is tracked outside of cr_groups in our ucred, convert
the syscalls to deal with only supplementary groups. Some remaining
stragglers in base that had baked in assumptions about these syscalls
are fixed in the process to avoid heartburn in conversion.
For relnotes: application developers should audit their use of both
setgroups(2) and getgroups(2) for signs that they had assumed the
previous FreeBSD behavior of using the first element for the egid. Any
calls to setgroups() to clear groups that used a single array of the
now or soon-to-be egid can be converted to setgroups(0, NULL) calls to
clear the supplementary groups entirely on all FreeBSD versions.
Co-authored-by: olce (but bugs are likely mine)
Relnotes: yes (see last paragraph)
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D51648
96 lines
2.8 KiB
Plaintext
96 lines
2.8 KiB
Plaintext
.\" Copyright (c) 1983, 1991, 1993, 1994
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd August 1, 2025
|
|
.Dt SETGROUPS 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm setgroups
|
|
.Nd set group access list
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/param.h
|
|
.In unistd.h
|
|
.Ft int
|
|
.Fn setgroups "int ngroups" "const gid_t *gidset"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn setgroups
|
|
system call
|
|
sets the supplementary group list of the current user process
|
|
according to the array
|
|
.Fa gidset .
|
|
The
|
|
.Fa ngroups
|
|
argument
|
|
indicates the number of entries in the array and must be no
|
|
more than
|
|
.Dv {NGROUPS_MAX} .
|
|
The
|
|
.Fa ngroups
|
|
argument may be set to 0 to clear the supplementary group list.
|
|
.Pp
|
|
Only the super-user may set a new supplementary group list.
|
|
.Sh RETURN VALUES
|
|
.Rv -std setgroups
|
|
.Sh ERRORS
|
|
The
|
|
.Fn setgroups
|
|
system call will fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EPERM
|
|
The caller is not the super-user.
|
|
.It Bq Er EINVAL
|
|
The number specified in the
|
|
.Fa ngroups
|
|
argument is larger than the
|
|
.Dv {NGROUPS_MAX}+1
|
|
limit.
|
|
.It Bq Er EFAULT
|
|
The address specified for
|
|
.Fa gidset
|
|
is outside the process
|
|
address space.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr getgroups 2 ,
|
|
.Xr initgroups 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn setgroups
|
|
system call appeared in
|
|
.Bx 4.2 .
|
|
.Pp
|
|
Before
|
|
.Fx 15.0 ,
|
|
the
|
|
.Fn setgroups
|
|
system call would set the effective group ID for the process to the first
|
|
element of
|
|
.Fa gidset .
|