setpriv: new applet

Add a minimal 'setpriv' implementation supporting the NO_NEW_PRIVS bit.
Typical usage:

    $ busybox setpriv sudo uname
    Linux
    $ busybox setpriv --nnp sudo uname
    sudo: effective uid is not 0, is /usr/bin/sudo on a file system with
    the 'nosuid' option set or an NFS file system without root privileges?

function                                             old     new   delta
packed_usage                                       31580   31685    +105
setpriv_main                                           -      87     +87
prctl                                                  -      53     +53
static.setpriv_longopts                                -      22     +22
applet_names                                        2620    2628      +8
applet_main                                         1516    1520      +4
------------------------------------------------------------------------------
(add/remove: 5/0 grow/shrink: 3/0 up/down: 279/0)             Total: 279 bytes

Signed-off-by: Assaf Gordon <assafgordon@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Assaf Gordon 2017-06-14 11:46:52 +02:00 committed by Denys Vlasenko
parent 2f24d30d01
commit 62d1e98fbd

73
util-linux/setpriv.c Normal file
View File

@ -0,0 +1,73 @@
/* vi: set sw=4 ts=4: */
/*
* setpriv implementation for busybox based on linux-utils-ng 2.29
*
* Copyright (C) 2017 by <assafgordon@gmail.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
*/
//config:config SETPRIV
//config: bool "setpriv"
//config: default y
//config: select PLATFORM_LINUX
//config: select LONG_OPTS
//config: help
//config: Run a program with different Linux privilege settings.
//config: Requires kernel >= 3.5
//applet:IF_SETPRIV(APPLET(setpriv, BB_DIR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_SETPRIV) += setpriv.o
//usage:#define setpriv_trivial_usage
//usage: "[OPTIONS] PROG [ARGS]"
//usage:#define setpriv_full_usage "\n\n"
//usage: "Run PROG with different privilege settings\n"
//usage: "\n--nnp,--no-new-privs Ignore setuid/setgid bits and file capabilities"
//setpriv from util-linux 2.28:
// -d, --dump show current state (and do not exec anything)
// --nnp, --no-new-privs disallow granting new privileges
// --inh-caps <caps,...> set inheritable capabilities
// --bounding-set <caps> set capability bounding set
// --ruid <uid> set real uid
// --euid <uid> set effective uid
// --rgid <gid> set real gid
// --egid <gid> set effective gid
// --reuid <uid> set real and effective uid
// --regid <gid> set real and effective gid
// --clear-groups clear supplementary groups
// --keep-groups keep supplementary groups
// --groups <group,...> set supplementary groups
// --securebits <bits> set securebits
// --selinux-label <label> set SELinux label
// --apparmor-profile <pr> set AppArmor profile
#include <sys/prctl.h>
#include "libbb.h"
#ifndef PR_SET_NO_NEW_PRIVS
#define PR_SET_NO_NEW_PRIVS 38
#endif
int setpriv_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int setpriv_main(int argc UNUSED_PARAM, char **argv)
{
static const char setpriv_longopts[] ALIGN1 =
"nnp\0" No_argument "\xff"
"no-new-privs\0" No_argument "\xff"
;
int opts;
opt_complementary = "-1";
applet_long_options = setpriv_longopts;
opts = getopt32(argv, "");
if (opts) {
if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0))
bb_simple_perror_msg_and_die("prctl: NO_NEW_PRIVS");
}
argv += optind;
BB_EXECVP_or_die(argv);
}