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newuidmap,newgidmap: New suid helpers for using subordinate uids and gids

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Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
This commit is contained in:
Eric W. Biederman 2013-01-22 01:20:07 -08:00 committed by Serge Hallyn
parent 2cffa14105
commit 673c2a6f9a
9 changed files with 856 additions and 2 deletions
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2
libmisc/Makefile.am
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@ -32,6 +32,8 @@ libmisc_a_SOURCES = \
getgr_nam_gid.c \
getrange.c \
hushed.c \
idmapping.h \
idmapping.c \
isexpired.c \
limits.c \
list.c log.c \

126
libmisc/idmapping.c Normal file
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@ -0,0 +1,126 @@
/*
* Copyright (c) 2013 Eric Biederman
* 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. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include "prototypes.h"
#include "idmapping.h"
struct map_range *get_map_ranges(int ranges, int argc, char **argv)
{
struct map_range *mappings, *mapping;
int idx, argidx;
if ((ranges * 3) > argc) {
fprintf(stderr, "ranges: %u argc: %d\n",
ranges, argc);
fprintf(stderr,
_( "%s: Not enough arguments to form %u mappings\n"),
Prog, ranges);
return NULL;
}
mappings = calloc(ranges, sizeof(*mappings));
if (!mappings) {
fprintf(stderr, _( "%s: Memory allocation failure\n"),
Prog);
exit(EXIT_FAILURE);
}
/* Gather up the ranges from the command line */
mapping = mappings;
for (idx = 0; idx < ranges; idx++, argidx += 3, mapping++) {
if (!getulong(argv[argidx + 0], &mapping->upper))
return NULL;
if (!getulong(argv[argidx + 1], &mapping->lower))
return NULL;
if (!getulong(argv[argidx + 2], &mapping->count))
return NULL;
}
return mappings;
}
/* Number of ascii digits needed to print any unsigned long in decimal.
* There are approximately 10 bits for every 3 decimal digits.
* So from bits to digits the formula is roundup((Number of bits)/10) * 3.
* For common sizes of integers this works out to:
* 2bytes --> 6 ascii estimate -> 65536 (5 real)
* 4bytes --> 12 ascii estimated -> 4294967296 (10 real)
* 8bytes --> 21 ascii estimated -> 18446744073709551616 (20 real)
* 16bytes --> 39 ascii estimated -> 340282366920938463463374607431768211456 (39 real)
*/
#define ULONG_DIGITS ((((sizeof(unsigned long) * CHAR_BIT) + 9)/10)*3)
void write_mapping(int proc_dir_fd, int ranges, struct map_range *mappings,
const char *map_file)
{
int idx;
struct map_range *mapping;
size_t bufsize;
char *buf, *pos;
int fd;
bufsize = ranges * ((ULONG_DIGITS + 1) * 3);
pos = buf = xmalloc(bufsize);
/* Build the mapping command */
mapping = mappings;
for (idx = 0; idx < ranges; idx++, mapping++) {
/* Append this range to the string that will be written */
int written = snprintf(pos, bufsize - (pos - buf),
"%lu %lu %lu\n",
mapping->upper,
mapping->lower,
mapping->count);
if ((written <= 0) || (written >= (bufsize - (pos - buf)))) {
fprintf(stderr, _("%s: snprintf failed!\n"), Prog);
exit(EXIT_FAILURE);
}
pos += written;
}
/* Write the mapping to the maping file */
fd = openat(proc_dir_fd, map_file, O_WRONLY);
if (fd < 0) {
fprintf(stderr, _("%s: open of %s failed: %s\n"),
Prog, map_file, strerror(errno));
exit(EXIT_FAILURE);
}
if (write(fd, buf, pos - buf) != (pos - buf)) {
fprintf(stderr, _("%s: write to %s failed: %s\n"),
Prog, map_file, strerror(errno));
exit(EXIT_FAILURE);
}
close(fd);
}

44
libmisc/idmapping.h Normal file
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@ -0,0 +1,44 @@
/*
* Copyright (c) 2013 Eric Biederman
* 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. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*/
#ifndef _IDMAPPING_H_
#define _IDMAPPING_H_
struct map_range {
unsigned long upper;
unsigned long lower;
unsigned long count;
};
extern struct map_range *get_map_ranges(int ranges, int argc, char **argv);
extern void write_mapping(int proc_dir_fd, int ranges,
struct map_range *mappings, const char *map_file);
#endif /* _ID_MAPPING_H_ */

4
man/Makefile.am
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@ -30,7 +30,9 @@ man_MANS = \
man1/login.1 \
man5/login.defs.5 \
man8/logoutd.8 \
man1/newgidmap.1 \
man1/newgrp.1 \
man1/newuidmap.1 \
man8/newusers.8 \
man8/nologin.8 \
man1/passwd.1 \
@ -83,7 +85,9 @@ man_XMANS = \
login.access.5.xml \
login.defs.5.xml \
logoutd.8.xml \
newgidmap.1.xml \
newgrp.1.xml \
newuidmap.1.xml \
newusers.8.xml \
nologin.8.xml \
passwd.1.xml \

157
man/newgidmap.1.xml Normal file
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@ -0,0 +1,157 @@
<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright (c) 2013 Eric W. Biederman
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. The name of the copyright holders or contributors may not be used to
endorse or promote products derived from this software without
specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
HOLDERS 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.
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='newgidmap.1'>
<refmeta>
<refentrytitle>newgidmap</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="sectdesc">User Commands</refmiscinfo>
<refmiscinfo class="source">shadow-utils</refmiscinfo>
<refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>newgidmap</refname>
<refpurpose>set the gid mapping of a user namespace</refpurpose>
</refnamediv>
<refsynopsisdiv id='synopsis'>
<cmdsynopsis>
<command>newgidmap</command>
<arg choice='plain'>
<replaceable>pid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>gid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>lowergid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>count</replaceable>
</arg>
<arg choice='opt'>
<arg choice='plain'>
<replaceable>pid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>gid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>lowergid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>count</replaceable>
</arg>
<arg choice='opt'>
<replaceable>...</replaceable>
</arg>
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
The <command>newgidmap</command> sets <filename>/proc/[pid]/gid_map</filename> based on it's
command line arguments and the gids allowed in <filename>/etc/subgid</filename>.
</para>
</refsect1>
<refsect1 id='options'>
<title>OPTIONS</title>
<para>
There currently are no options to the <command>newgidmap</command> command.
</para>
<variablelist remap='IP'>
</variablelist>
</refsect1>
<refsect1 id='note'>
<title>NOTE</title>
<para>
The only restriction placed on the login shell is that the command
name must be listed in <filename>/etc/shells</filename>, unless the
invoker is the superuser, and then any value may be added. An
account with a restricted login shell may not change her login shell.
For this reason, placing <filename>/bin/rsh</filename> in
<filename>/etc/shells</filename> is discouraged since accidentally
changing to a restricted shell would prevent the user from ever
changing her login shell back to its original value.
</para>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<variablelist>
<varlistentry>
<term><filename>/etc/subgid</filename></term>
<listitem>
<para>List of users subordinate user IDs.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/proc/[pid]/gid_map</filename></term>
<listitem>
<para>Mapping of gids from one between user namespaces.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>login.defs</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>usermod</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>newusers</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>userdel</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>subgid</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>.
</para>
</refsect1>
</refentry>

154
man/newuidmap.1.xml Normal file
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@ -0,0 +1,154 @@
<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright (c) 2013 Eric W. Biederman
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. The name of the copyright holders or contributors may not be used to
endorse or promote products derived from this software without
specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
HOLDERS 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.
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='newuidmap.1'>
<refmeta>
<refentrytitle>newuidmap</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="sectdesc">User Commands</refmiscinfo>
<refmiscinfo class="source">shadow-utils</refmiscinfo>
<refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>newuidmap</refname>
<refpurpose>set the uid mapping of a user namespace</refpurpose>
</refnamediv>
<refsynopsisdiv id='synopsis'>
<cmdsynopsis>
<command>newuidmap</command>
<arg choice='plain'>
<replaceable>pid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>uid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>loweruid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>count</replaceable>
</arg>
<arg choice='opt'>
<arg choice='plain'>
<replaceable>uid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>loweruid</replaceable>
</arg>
<arg choice='plain'>
<replaceable>count</replaceable>
</arg>
<arg choice='opt'>
<replaceable>...</replaceable>
</arg>
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
The <command>newuidmap</command> sets <filename>/proc/[pid]/uid_map</filename> based on it's
command line arguments and the uids allowed in <filename>/etc/subuid</filename>.
</para>
</refsect1>
<refsect1 id='options'>
<title>OPTIONS</title>
<para>
There currently are no options to the <command>newuidmap</command> command.
</para>
<variablelist remap='IP'>
</variablelist>
</refsect1>
<refsect1 id='note'>
<title>NOTE</title>
<para>
The only restriction placed on the login shell is that the command
name must be listed in <filename>/etc/shells</filename>, unless the
invoker is the superuser, and then any value may be added. An
account with a restricted login shell may not change her login shell.
For this reason, placing <filename>/bin/rsh</filename> in
<filename>/etc/shells</filename> is discouraged since accidentally
changing to a restricted shell would prevent the user from ever
changing her login shell back to its original value.
</para>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<variablelist>
<varlistentry>
<term><filename>/etc/subuid</filename></term>
<listitem>
<para>List of users subordinate user IDs.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/proc/[pid]/uid_map</filename></term>
<listitem>
<para>Mapping of uids from one between user namespaces.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>login.defs</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>usermod</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>newusers</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>userdel</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>subuid</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>.
</para>
</refsect1>
</refentry>

5
src/Makefile.am
View File

@ -24,7 +24,8 @@ INCLUDES = \
bin_PROGRAMS = groups login su
sbin_PROGRAMS = nologin
ubin_PROGRAMS = faillog lastlog chage chfn chsh expiry gpasswd newgrp passwd
ubin_PROGRAMS = faillog lastlog chage chfn chsh expiry gpasswd newgrp passwd \
newgidmap newuidmap
usbin_PROGRAMS = \
chgpasswd \
chpasswd \
@ -49,7 +50,7 @@ usbin_PROGRAMS = \
noinst_PROGRAMS = id sulogin
suidbins = su
suidubins = chage chfn chsh expiry gpasswd newgrp passwd
suidubins = chage chfn chsh expiry gpasswd newgrp passwd newuidmap newgidmap
if ACCT_TOOLS_SETUID
suidubins += chage chgpasswd chpasswd groupadd groupdel groupmod newusers useradd userdel usermod
endif

183
src/newgidmap.c Normal file
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@ -0,0 +1,183 @@
/*
* Copyright (c) 2013 Eric Biederman
* 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. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*/
#include <config.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "defines.h"
#include "prototypes.h"
#include "subordinateio.h"
#include "idmapping.h"
/*
* Global variables
*/
const char *Prog;
static bool verify_range(struct passwd *pw, struct map_range *range)
{
/* An empty range is invalid */
if (range->count == 0)
return false;
/* Test /etc/subgid */
if (have_sub_gids(pw->pw_name, range->lower, range->count))
return true;
/* Allow a process to map it's own gid */
if ((range->count == 1) && (pw->pw_gid == range->lower))
return true;
return false;
}
static void verify_ranges(struct passwd *pw, int ranges,
struct map_range *mappings)
{
struct map_range *mapping;
int idx;
mapping = mappings;
for (idx = 0; idx < ranges; idx++, mapping++) {
if (!verify_range(pw, mapping)) {
fprintf(stderr, _( "%s: gid range [%lu-%lu) -> [%lu-%lu) not allowed\n"),
Prog,
mapping->upper,
mapping->upper + mapping->count,
mapping->lower,
mapping->lower + mapping->count);
exit(EXIT_FAILURE);
}
}
}
static void usage(void)
{
fprintf(stderr, _("usage: %s <pid> <gid> <lowergid> <count> [ <gid> <lowergid> <count> ] ... \n"), Prog);
exit(EXIT_FAILURE);
}
/*
* newgidmap - Set the gid_map for the specified process
*/
int main(int argc, char **argv)
{
char proc_dir_name[PATH_MAX];
char *target_str;
pid_t target, parent;
int proc_dir_fd;
int ranges;
struct map_range *mappings;
struct stat st;
struct passwd *pw;
int written;
Prog = Basename (argv[0]);
/*
* The valid syntax are
* newgidmap target_pid
*/
if (argc < 2)
usage();
/* Find the process that needs it's user namespace
* gid mapping set.
*/
target_str = argv[1];
if (!get_pid(target_str, &target))
usage();
written = snprintf(proc_dir_name, sizeof(proc_dir_name), "/proc/%u/",
target);
if ((written <= 0) || (written >= sizeof(proc_dir_name))) {
fprintf(stderr, "%s: snprintf of proc path failed: %s\n",
Prog, strerror(errno));
}
proc_dir_fd = open(proc_dir_name, O_DIRECTORY);
if (proc_dir_fd < 0) {
fprintf(stderr, _("%s: Could not open proc directory for target %u\n"),
Prog, target);
return EXIT_FAILURE;
}
/* Who am i? */
pw = get_my_pwent ();
if (NULL == pw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
(unsigned long) getuid ()));
return EXIT_FAILURE;
}
/* Get the effective uid and effective gid of the target process */
if (fstat(proc_dir_fd, &st) < 0) {
fprintf(stderr, _("%s: Could not stat directory for target %u\n"),
Prog, target);
return EXIT_FAILURE;
}
/* Verify real user and real group matches the password entry
* and the effective user and group of the program whose
* mappings we have been asked to set.
*/
if ((getuid() != pw->pw_uid) ||
(getgid() != pw->pw_gid) ||
(pw->pw_uid != st.st_uid) ||
(pw->pw_gid != st.st_gid)) {
fprintf(stderr, _( "%s: Target %u is owned by a different user\n" ),
Prog, target);
return EXIT_FAILURE;
}
if (!sub_gid_open(O_RDONLY)) {
return EXIT_FAILURE;
}
ranges = ((argc - 2) + 2) / 3;
mappings = get_map_ranges(ranges, argc - 2, argv + 2);
if (!mappings)
usage();
verify_ranges(pw, ranges, mappings);
write_mapping(proc_dir_fd, ranges, mappings, "gid_map");
sub_gid_close();
return EXIT_SUCCESS;
}

183
src/newuidmap.c Normal file
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@ -0,0 +1,183 @@
/*
* Copyright (c) 2013 Eric Biederman
* 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. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*/
#include <config.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "defines.h"
#include "prototypes.h"
#include "subordinateio.h"
#include "idmapping.h"
/*
* Global variables
*/
const char *Prog;
static bool verify_range(struct passwd *pw, struct map_range *range)
{
/* An empty range is invalid */
if (range->count == 0)
return false;
/* Test /etc/subuid */
if (have_sub_uids(pw->pw_name, range->lower, range->count))
return true;
/* Allow a process to map it's own uid */
if ((range->count == 1) && (pw->pw_uid == range->lower))
return true;
return false;
}
static void verify_ranges(struct passwd *pw, int ranges,
struct map_range *mappings)
{
struct map_range *mapping;
int idx;
mapping = mappings;
for (idx = 0; idx < ranges; idx++, mapping++) {
if (!verify_range(pw, mapping)) {
fprintf(stderr, _( "%s: uid range [%lu-%lu) -> [%lu-%lu) not allowed\n"),
Prog,
mapping->upper,
mapping->upper + mapping->count,
mapping->lower,
mapping->lower + mapping->count);
exit(EXIT_FAILURE);
}
}
}
void usage(void)
{
fprintf(stderr, _("usage: %s <pid> <uid> <loweruid> <count> [ <uid> <loweruid> <count> ] ... \n"), Prog);
exit(EXIT_FAILURE);
}
/*
* newuidmap - Set the uid_map for the specified process
*/
int main(int argc, char **argv)
{
char proc_dir_name[PATH_MAX];
char *target_str;
pid_t target, parent;
int proc_dir_fd;
int ranges;
struct map_range *mappings;
struct stat st;
struct passwd *pw;
int written;
Prog = Basename (argv[0]);
/*
* The valid syntax are
* newuidmap target_pid
*/
if (argc < 2)
usage();
/* Find the process that needs it's user namespace
* uid mapping set.
*/
target_str = argv[1];
if (!get_pid(target_str, &target))
usage();
written = snprintf(proc_dir_name, sizeof(proc_dir_name), "/proc/%u/",
target);
if ((written <= 0) || (written >= sizeof(proc_dir_name))) {
fprintf(stderr, "%s: snprintf of proc path failed: %s\n",
Prog, strerror(errno));
}
proc_dir_fd = open(proc_dir_name, O_DIRECTORY);
if (proc_dir_fd < 0) {
fprintf(stderr, _("%s: Could not open proc directory for target %u\n"),
Prog, target);
return EXIT_FAILURE;
}
/* Who am i? */
pw = get_my_pwent ();
if (NULL == pw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
(unsigned long) getuid ()));
return EXIT_FAILURE;
}
/* Get the effective uid and effective gid of the target process */
if (fstat(proc_dir_fd, &st) < 0) {
fprintf(stderr, _("%s: Could not stat directory for target %u\n"),
Prog, target);
return EXIT_FAILURE;
}
/* Verify real user and real group matches the password entry
* and the effective user and group of the program whose
* mappings we have been asked to set.
*/
if ((getuid() != pw->pw_uid) ||
(getgid() != pw->pw_gid) ||
(pw->pw_uid != st.st_uid) ||
(pw->pw_gid != st.st_gid)) {
fprintf(stderr, _( "%s: Target %u is owned by a different user\n" ),
Prog, target);
return EXIT_FAILURE;
}
if (!sub_uid_open(O_RDONLY)) {
return EXIT_FAILURE;
}
ranges = ((argc - 2) + 2) / 3;
mappings = get_map_ranges(ranges, argc - 2, argv + 2);
if (!mappings)
usage();
verify_ranges(pw, ranges, mappings);
write_mapping(proc_dir_fd, ranges, mappings, "uid_map");
sub_uid_close();
return EXIT_SUCCESS;
}