Commit Graph

1184 Commits

Author SHA1 Message Date
Iker Pedrosa
3b89b71680 Initialize local variables
CWE-457 by CodeQL.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-24 07:49:11 -05:00
Iker Pedrosa
23baa40d9d Remove redeclared variable
No need to redeclare a variable with the same name and type. Just keep
the one with the biggest scope.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-24 07:49:11 -05:00
Iker Pedrosa
45d6746219 src: correct "badname" option
Change "badnames" to "badname" as this is the accepted option name.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-06 10:13:51 -05:00
Iker Pedrosa
0593b330d8 Suggest badname if name has special characters
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2076819

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-06 10:13:51 -05:00
Christian Göttsche
58b6e97a9e passwd: erase password copy on all error branches 2022-04-30 13:19:14 -05:00
Matheus Marques
edca359022 usermod: fix alphabetical order in help message 2022-04-25 21:33:11 -05:00
juyin
9cdb5251b6 chpasswd: add IS_CRYPT_METHOD
Use macro IS_CRYPT_METHOD instead of ’strcmp(crypt_method, xx)==0’ to make the code more cleanup
2022-04-03 21:07:09 -05:00
juyin
3c1e5fcf16 refactor get_salt function
refactor get_salt function to make it easier to read.
2022-04-03 21:07:09 -05:00
juyin
3732cf72d6 chpasswd: fix function problem with -R parameter
Generating salt value depends on /dev/urandom. But after the
function process_root_flag changed the root directory, It does
not exist.

So, generate salt value before changeing the directory.

Fixes: #514
2022-04-03 21:07:09 -05:00
juyin
a026154c6f chpasswd: add get_salt for generating salt value
The function that generates the salt value is extracted separately, and it is more convenient to modify it later.
2022-04-03 21:07:09 -05:00
Steve Grubb
4f393a5f9f Change to strncat
ut_line is declared as a nonstring in bits/utmp.h. It might not be NUL
terminated. Limit how much it copies to the size of the array.
2022-03-18 16:02:01 -05:00
ed neville
b7bbf1beb8 Fix code comment
Improving check around pw_dir which may be NULL
2022-03-13 09:06:36 -05:00
Iker Pedrosa
f1f1678e13 useradd: modify check ID range for system users
useradd warns that a system user ID less than SYS_UID_MIN is outside the
expected range, even though that ID has been specifically selected with
the "-u" option.

In my opinion all the user ID's below SYS_UID_MAX are for the system,
thus I change the condition to take that into account.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2004911

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-01-19 10:02:55 -06:00
Alejandro Colomar
fd5945e533 Use 'void' instead of 'RETSIGTYPE'. Use 'sighandler_t' too.
C89 and POSIX.1-2001 define signal(2) as returning a pointer to a
function returning 'void'.  K&R C signal(2) signature is obsolete.
Use 'void' directly.

Also, instead of writing the function pointer type explicitly, use
POSIX's 'sighandler_t'.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2022-01-15 08:25:53 -06:00
Christian Göttsche
a8166a86ed Declare read-only arguments of run_part(s) const
run_part() and run_parts() do not modify their directory, name and
action arguments.
Also include the header in the implementation to provide the prototypes.

useradd.c:2495:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
 2495 |         if (run_parts ("/etc/shadow-maint/useradd-pre.d", (char*)user_name,
      |                                                           ^
useradd.c:2495:24: warning: passing argument 1 of ‘run_parts’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
 2495 |         if (run_parts ("/etc/shadow-maint/useradd-pre.d", (char*)user_name,
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from useradd.c:45:
../lib/run_part.h:2:22: note: expected ‘char *’ but argument is of type ‘const char *’
    2 | int run_parts (char *directory, char *name, char *action);
      |                ~~~~~~^~~~~~~~~
useradd.c:2496:25: warning: passing argument 3 of ‘run_parts’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
 2496 |                         "useradd")) {
      |                         ^~~~~~~~~
2022-01-03 15:09:17 +01:00
Christian Göttsche
debea9b761 Avoid unused variable warnings when building with PAM
newusers.c:467:15: warning: unused variable ‘cp’ [-Wunused-variable]
  467 |         char *cp;
      |               ^~

newusers.c:611:13: warning: unused variable ‘bad_s’ [-Wunused-variable]
  611 |         int bad_s;
      |             ^~~~~
2022-01-03 15:09:17 +01:00
Christian Göttsche
7909308285 Declare read-only lookup pointers const
pwck.c:587:31: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  587 |                         spw = (struct spwd *) spw_locate (pwd->pw_name);
      |                               ^

grpck.c:599:31: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  599 |                         sgr = (struct sgrp *) sgr_locate (grp->gr_name);
      |                               ^

grpck.c:761:23: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  761 |                 grp = (struct group *) gr_locate (sgr->sg_name);
      |                       ^
2022-01-03 15:09:17 +01:00
Christian Göttsche
a74114fe34 Declare variable for string literal const
newgidmap.c:87:16: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
   87 |         policy = "deny\n";
      |                ^
2022-01-03 15:09:17 +01:00
Christian Göttsche
946eb84182 Do not drop const qualifier for Basename
The private Basename() implementation does not modify its argument, so
a cast to a non-const char pointer is not necessary.

newgrp.c:790:39: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  790 |         progbase = (char *) Basename ((char *) prog);
      |                                       ^
newgrp.c:790:20: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  790 |         progbase = (char *) Basename ((char *) prog);
      |                    ^

shell.c:48:70: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   48 |                 (void) snprintf (arg0, sizeof arg0, "-%s", Basename ((char *) file));
      |                                                                      ^
2022-01-03 15:09:17 +01:00
Christian Göttsche
f84b8530c5 Declare file local functions static 2022-01-03 15:09:17 +01:00
Serge Hallyn
e8a2cfa7dc
Merge pull request #451 from hallyn/2021-12-05/license 2022-01-02 18:38:42 -06:00
Xi Ruoyao
6f266a30ff
fix segfault running useradd -D 2021-12-29 17:06:39 +08:00
Serge Hallyn
e668c7e725
Merge pull request #479 from alejandro-colomar/getgroups
Remove HAVE_GETGROUPS ifdefs
2021-12-27 19:12:24 -06:00
Alejandro Colomar
913e16ce20 Remove HAVE_GETGROUPS ifdefs
getgroups(2) has been in POSIX since POSIX.1-2001.  It is also in
in SVr4 and in 4.3BSD (see getgroups(2) and getgroups(3p)).
We can assume that this function is always available.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-27 21:17:50 +01:00
Alejandro Colomar
3e602b58a2 Remove HAVE_STRFTIME ifdefs
strftime(3) has been in standard C since C89.  It is also in
POSIX.1-2001, and in SVr4 (see strftime(3) and strftime(3p)).
We can assume that this function is always available.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-27 20:50:13 +01:00
Serge Hallyn
e1b1d187f4
Merge pull request #467 from alejandro-colomar/date_to_str
Have a single definition of date_to_str()
2021-12-27 09:53:00 -06:00
Alejandro Colomar
355ad6a9e0 Have a single definition of date_to_str()
PARAMETERS:

According to the C2x charter, I reordered the parameters 'size'
and 'buf' from previously existing date_to_str() definitions.

C2x charter:
> 15. Application Programming Interfaces (APIs) should be
> self-documenting when possible.  In particular, the order of
> parameters in function declarations should be arranged such that
> the size of an array appears before the array.  The purpose is to
> allow Variable-Length Array (VLA) notation to be used.  This not
> only makes the code's purpose clearer to human readers, but also
> makes static analysis easier.  Any new APIs added to the Standard
> should take this into consideration.

I used 'long' for the date parameter, as some uses of the function
need to pass a negative value meaning "never".

FUNCTION BODY:

I didn't check '#ifdef HAVE_STRFTIME', which old definitions did,
since strftime(3) is guaranteed by the C89 standard, and all of
the conversion specifiers that we use are also specified by that
standard, so we don't need any extensions at all.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-26 18:55:39 +01:00
Serge Hallyn
f93cf255d4 Update licensing info
Closes #238

Update all files to list SPDX license shortname.  Most files are
BSD 3 clause license.

The exceptions are:

serge@sl ~/src/shadow$ git grep SPDX-License | grep -v BSD-3-Clause
contrib/atudel:# SPDX-License-Identifier: BSD-4-Clause
lib/tcbfuncs.c: * SPDX-License-Identifier: 0BSD
libmisc/salt.c: * SPDX-License-Identifier: Unlicense
src/login_nopam.c: * SPDX-License-Identifier: Unlicense
src/nologin.c: * SPDX-License-Identifier: BSD-2-Clause
src/vipw.c: * SPDX-License-Identifier: GPL-2.0-or-later

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-12-23 19:36:50 -06:00
Serge Hallyn
79157cbad8 Make shadow_logfd and Prog not extern
Closes #444
Closes #465

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-12-23 15:18:07 -06:00
Serge Hallyn
a630fba34b
Merge pull request #461 from edneville/441_passwd_message
passwd -l should not say that it changes expiry
2021-12-19 11:27:44 -06:00
ed neville
92cb9d7785 passwd -l should not say that it changes expiry
Closes #441
2021-12-17 23:02:02 +00:00
Serge Hallyn
0f31dc5c2c
Merge pull request #458 from edneville/434_usermod_home_dir_trailing_slash
Remove tailing slash on home dir
2021-12-17 08:41:26 -06:00
Serge Hallyn
2a6164cc4a
Merge pull request #455 from alejandro-colomar/master
usermod: Remove special case for ""
2021-12-17 08:33:47 -06:00
ed neville
53763ae6ee Remove tailing slash on home dir
Closes #434

Signed-off-by: ed neville <ed@s5h.net>
2021-12-17 12:23:52 +00:00
Tobias Stoeckmann
c0e4ccd032 Verify default SIGCHLD handling.
The SIGCHLD handler could have been ignored by parent process.
Make sure that we have default handling activated.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
2021-12-15 11:26:51 +01:00
Alejandro Colomar
e2f1fcca0e usermod: Remove special case for ""
That special case is already handled by the called function: strtoday()
so we can simplify the calling code.

Link: <https://github.com/shadow-maint/shadow/issues/454>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-14 12:40:09 +01:00
Andy Zaugg
aaaaf21b6f Adding new option -rG to usermod
Adding a new switch -rG, which provides a similar feature set to
-aG, allowing a person to list exactly what groups to remove a
user from.

https://github.com/shadow-maint/shadow/issues/337
2021-12-13 21:42:48 -08:00
Serge Hallyn
abb879fd4f
Merge pull request #449 from hallyn/2021-11-27/libsubid-symbols
2021 11 27/libsubid symbols
2021-12-07 08:58:03 -06:00
Serge Hallyn
c628caf174
Merge pull request #408 from bjorn-fischer/ambient_caps
Add support for ambient capabilities
2021-12-05 08:05:06 -06:00
Björn Fischer
6938bab429 Call pam_end() after fork in child code path
This conforms to PAM documentation and it is needed to support
ambient capabilities with PAM + libcap-2.58+.

Signed-off-by: Björn Fischer <bf@CeBiTec.Uni-Bielefeld.DE>
2021-12-05 08:03:56 -06:00
Serge Hallyn
19f08785f0
Merge pull request #231 from gjzkrug/useradd-maildir-fix
Removed hard-coded default mail spool in useradd
2021-12-04 22:26:51 -06:00
Ludwig Nussel
d12d300c98 useradd: assume uid 0 == root as fallback
In absence of /etc/passwd, eg when bootstrapping a chroot, resolving
uid 0 to a name may not work. Therefore just assume "root".
2021-11-30 17:14:14 +01:00
Serge Hallyn
32f641b207 Change the subid export symbols
Rename libsubid symbols to all be prefixed with subid_.

Don't export anything but the subid_*.

Closes #443

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-11-27 14:56:03 -06:00
Serge Hallyn
3ff3cd9c78
Merge pull request #440 from stoeckmann/vipw
Improve child error handling
2021-11-22 07:33:57 -06:00
Serge Hallyn
1fdaf69376
Merge pull request #436 from ikerexxe/getsubids
getsubids: system binary for user's sub*ids
2021-11-18 07:32:10 -06:00
Iker Pedrosa
3b6ccf642c getsubids: system binary for user's sub*ids
Rename list_subid_ranges to getsubids to provide a system binary to
check the sub*ids of a user. The intention is to provide this binary
with any distribution that includes the subid feature, so that system
administrators can check the subid ranges of a given user.

Finally, add a man page to explain the behaviour of getsubids.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1980780

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-11-17 16:35:50 +01:00
Serge Hallyn
126fbe57bc
Merge pull request #437 from ikerexxe/newgrp_segfault
newgrp: fix segmentation fault
2021-11-17 08:18:13 -06:00
Serge Hallyn
6c3d4ebf6e
Merge pull request #439 from ikerexxe/useradd_skel_fix
useradd: change SELinux labels for home files
2021-11-17 08:17:34 -06:00
Iker Pedrosa
d8e54618fe pwck: fix segfault when calling fprintf()
As shadow_logfd variable is not set at the beginning of the program if
something fails and fprintf() is called a segmentation fault happens.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2021339

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-11-15 12:45:08 +01:00
Tobias Stoeckmann
624d57c08c Improve child error handling
Always set SIGCHLD handler to default, even if the caller of vipw has
set SIGCHLD to ignore. If SIGCHLD is ignored no zombie processes would
be created, which in turn could mean that kill is called with an already
recycled pid.

Proof of Concept:

1. Compile nochld:
 --
 #include <signal.h>
 #include <unistd.h>
 int main(void) {
 char *argv[] = { "vipw", NULL };
 signal(SIGCHLD, SIG_IGN);
 execvp("vipw", argv);
 return 1;
 }
 --
2. Run nochld
3. Suspend child vi, which suspends vipw too:
`kill -STOP childpid`
4. Kill vi:
`kill -9 childpid`
5. You can see with ps that childpid is no zombie but disappeared
6. Bring vipw back into foreground
`fg`

The kill call sends SIGCONT to "childpid" which in turn could have been
already recycled for another process.

This is definitely not a vulnerability. It would take super user
operations, at which point an attacker would have already elevated
permissions.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
2021-11-14 12:01:32 +01:00
Iker Pedrosa
06eb4e4d76 useradd: change SELinux labels for home files
Change SELinux labels for files copied from the skeleton directory to
the home directory.

This could cause gnome's graphical user adding to fail without copying
the full skeleton files.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2022658

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-11-12 15:27:16 +01:00
Iker Pedrosa
497e90751b newgrp: fix segmentation fault
Fix segmentation fault in newgrp when xgetspnam() returns a NULL value
that is immediately freed.

The error was committed in
e65cc6aebc

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2019553

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-11-10 12:02:04 +01:00
Serge Hallyn
387da46d73
Merge pull request #423 from lrh2000/su-fix-sigkill
su: Fix never alarmed SIGKILL when session terminates
2021-10-31 12:36:03 -05:00
Iker Pedrosa
09c752f00f useradd: create directories after the SELinux user
Create the home and mail folders after the SELinux user has been set for
the added user. This will allow the folders to be created with the
SELinux user label.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-10-25 09:55:27 +02:00
Ruihan Li
5b4082d007 su: Fix never alarmed SIGKILL when session terminates
The buggy code was introduced nearly 5 years ago at the
commit 08fd4b69e8. The
desired behavior is that SIGKILL will be sent to the
child if it does not exit within 2 seconds after it
receives SIGTERM. However, SIGALRM is masked while
waiting for the child so it cannot wake the program
up after 2 seconds to send SIGKILL.

An example shows the buggy behavior, which exists in
Ubuntu 18.04 LTS (with login 1:4.5-1ubuntu2).
```bash
user1@localhost:~$ su user2 -c '
_term() {
  echo SIGTERM received
}
trap _term TERM

while true; do
  sleep 1
  echo still alive
done'
Password:
still alive

Session terminated, terminating shell...Terminated
SIGTERM received
still alive
still alive
still alive
still alive
```
(SIGTERM is sent in another user1's terminal by
executing `killall su`.)

Here is the desired behavior, which shows what the
commit fixes.
```bash
user1@localhost:~$ su user2 -c '
_term() {
  echo SIGTERM received
}
trap _term TERM

while true; do
  sleep 1
  echo still alive
done'
Password:
still alive

Session terminated, terminating shell...Terminated
SIGTERM received
still alive
still alive
 ...killed.
user1@localhost:~$ echo $?
255
```
2021-10-25 13:39:41 +08:00
Andy Zaugg
7e2b522a15 Added a new configurable LOG_INIT to useradd
In some circumstances I want the default behaviour of useradd to
not add user entries to the lastlog and faillog databases. Allowing
this options behaviour to be controlled by the config file
/etc/default/useradd.
2021-10-15 16:20:52 -05:00
Serge Hallyn
4ad2697cc4
Merge pull request #412 from ljmf00/fix-trailing-whitespaces
treewide: remove trailing whitespaces
2021-09-27 10:12:24 -05:00
Michael Vetter
117bc66c6f Only free sgent if it was initialized
`sgent` is only initialized in `get_group()` if `is_shadowgrp` is true.
So we should also only attempt to free it if this is actually the case.

Can otherwise lead to:
```
free() double free detected in tcache 2 (gpasswd)
```
2021-09-20 11:04:50 +02:00
Luís Ferreira
7903557988
treewide: remove trailing whitespaces
Signed-off-by: Luís Ferreira <contact@lsferreira.net>
2021-09-13 17:23:17 +01:00
Serge Hallyn
0e0101043b
Merge pull request #405 from a1346054/master
Minor cleanups
2021-09-13 10:57:38 -05:00
Luís Ferreira
679a29da7e
git: ignore generated check_subid_range
Signed-off-by: Luís Ferreira <contact@lsferreira.net>
2021-09-13 16:17:49 +01:00
a1346054
7687ae4dbd fix spelling and unify whitespace 2021-08-18 18:06:02 +00:00
Serge Hallyn
4624e9fca1 Revert "useradd.c:fix memleaks of grp"
In some cases, the value which was being freed is not actually
safe to free.

Closes #394

This reverts commit c44b71cec2.
2021-08-14 19:37:24 -05:00
Serge Hallyn
049b08481a useradd.c: Fix undeclared subuid_count when not using subids
subuid_count won't get used by usr_update(), but since we're passing it
as an argument we have to make sure it's always defined.  So just define
it as pre-set to 0.

Closes #402

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-08-14 19:25:51 -05:00
Iker Pedrosa
9dd720a285 useradd: avoid generating an empty subid range
useradd generates an empty subid range when adding a new user. This is
caused because there are two variables, one local and the other one
global, that have a very similar name and they are used indistinctly in
the code. The local variable loads the SUB_*ID_COUNT configuration from
the login.defs file, while the global variable, which holds a value of
0, is used to generate the subid range. Causing the empty subid range
problem.

I've merged the two variables in the local one and removed the global
variable. I prefer to do it this way to reduce the scope of it but I'm
open to doing it the other way round.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1990653

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-08-10 10:04:39 +02:00
Serge Hallyn
1c1e0b0c68
Merge pull request #397 from ikerexxe/revert_local_groups_check
usermod: allow all group types with -G option
2021-08-04 10:41:56 -05:00
Serge Hallyn
adb83f7796
Merge pull request #398 from Dzejrou/master
passwd: handle NULL pw_passwd when printing password status
2021-08-04 10:38:30 -05:00
Jaroslav Jindrak
05388f748d passwd: handle NULL pw_passwd when printing password status
When the -S and -a options are used for passwd to list the status
of all passwords, there is a chance the pw_passwd field of struct
passwd will be NULL. This can be due to 'files compat' being set
for passwd in /etc/nsswitch.conf and the usage of some features
not available in the 'files' mode (e.g. a plus sign at the start
of a line).

Example:

germ161:~ # grep passwd /etc/nsswitch.conf
passwd: files compat
germ161:~ # rpm -qa shadow
shadow-4.2.1-34.20.x86_64
germ161:~ # grep passwd /etc/nsswitch.conf
passwd: files compat
germ161:~ # grep + /etc/passwd
+@nisgroup
germ161:~ # passwd -S -a > /dev/null
Segmentation fault (core dumped)

With this commit:

germ161:~ # passwd -S -a > /dev/null
passwd: malformed password data obtained for user +@nisgroup
2021-08-03 20:03:46 +02:00
Iker Pedrosa
e481437ab9 usermod: allow all group types with -G option
The only way of removing a group from the supplementary list is to use
-G option, and list all groups that the user is a member of except for
the one that wants to be removed. The problem lies when there's a user
that contains both local and remote groups, and the group to be removed
is a local one. As we need to include the remote group with -G option
the command will fail.

This reverts commit 140510de9d. This way,
it would be possible to remove the remote groups from the supplementary
list.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1967641
Resolves: https://github.com/shadow-maint/shadow/issues/338

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-08-03 11:14:09 +02:00
Iker Pedrosa
c6847011e8 Makefile: include libeconf dependency in new*idmap
new*idmap has a dependency with libeconf since commit
c464ec5570. I'm just adding it to the
Makefile to be able to compile in distributions that include libeconf.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-08-02 15:54:20 +02:00
Serge Hallyn
33c33a32a2 useradd: create /etc/default saving defaults.
Since bbf4b79, we stopped shipping /etc/default/useradd, and therefore
install of shadow does not auto-create /etc/default.  So when useradd
tries to save a new default, it needs to create the directory.

Closes #390.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-07-25 16:19:56 -05:00
Serge Hallyn
537b8cd90b Fix out of tree builds with respect to libsubid includes
There's a better way to do this, and I hope to clean that up,
but this fixes out of tree builds for me right now.

Closes #386

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-07-23 17:51:13 -05:00
Serge Hallyn
9eb191edc4
Merge pull request #359 from ikerexxe/rest_resource_leak
Fix covscan RESOURCE_LEAK
2021-06-24 13:14:15 -05:00
Iker Pedrosa
e65cc6aebc Fix covscan RESOURCE_LEAK
Error: RESOURCE_LEAK (CWE-772): [#def1]
shadow-4.8.1/lib/commonio.c:320: alloc_fn: Storage is returned from allocation function "fopen_set_perms".
shadow-4.8.1/lib/commonio.c:320: var_assign: Assigning: "bkfp" = storage returned from "fopen_set_perms(backup, "w", &sb)".
shadow-4.8.1/lib/commonio.c:329: noescape: Resource "bkfp" is not freed or pointed-to in "putc".
shadow-4.8.1/lib/commonio.c:334: noescape: Resource "bkfp" is not freed or pointed-to in "fflush".
shadow-4.8.1/lib/commonio.c:339: noescape: Resource "bkfp" is not freed or pointed-to in "fileno".
shadow-4.8.1/lib/commonio.c:342: leaked_storage: Variable "bkfp" going out of scope leaks the storage it points to.
  340|   	    || (fclose (bkfp) != 0)) {
  341|   		/* FIXME: unlink the backup file? */
  342|-> 		return -1;
  343|   	}
  344|

Error: RESOURCE_LEAK (CWE-772): [#def2]
shadow-4.8.1/libmisc/addgrps.c:69: alloc_fn: Storage is returned from allocation function "malloc".
shadow-4.8.1/libmisc/addgrps.c:69: var_assign: Assigning: "grouplist" = storage returned from "malloc(i * 4UL)".
shadow-4.8.1/libmisc/addgrps.c:73: noescape: Resource "grouplist" is not freed or pointed-to in "getgroups". [Note: The source code implementation of the function has been overridden by a builtin model.]
shadow-4.8.1/libmisc/addgrps.c:126: leaked_storage: Variable "grouplist" going out of scope leaks the storage it points to.
  124|   	}
  125|
  126|-> 	return 0;
  127|   }
  128|   #else				/* HAVE_SETGROUPS && !USE_PAM */

Error: RESOURCE_LEAK (CWE-772): [#def3]
shadow-4.8.1/libmisc/chowntty.c:62: alloc_fn: Storage is returned from allocation function "getgr_nam_gid".
shadow-4.8.1/libmisc/chowntty.c:62: var_assign: Assigning: "grent" = storage returned from "getgr_nam_gid(getdef_str("TTYGROUP"))".
shadow-4.8.1/libmisc/chowntty.c:98: leaked_storage: Variable "grent" going out of scope leaks the storage it points to.
   96|   	 */
   97|   #endif
   98|-> }
   99|

Error: RESOURCE_LEAK (CWE-772): [#def4]
shadow-4.8.1/libmisc/copydir.c:742: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/libmisc/copydir.c:742: var_assign: Assigning: "ifd" = handle returned from "open(src, 0)".
shadow-4.8.1/libmisc/copydir.c:748: leaked_handle: Handle variable "ifd" going out of scope leaks the handle.
  746|   #ifdef WITH_SELINUX
  747|   	if (set_selinux_file_context (dst, NULL) != 0) {
  748|-> 		return -1;
  749|   	}
  750|   #endif				/* WITH_SELINUX */

Error: RESOURCE_LEAK (CWE-772): [#def5]
shadow-4.8.1/libmisc/copydir.c:751: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/libmisc/copydir.c:751: var_assign: Assigning: "ofd" = handle returned from "open(dst, 577, statp->st_mode & 0xfffU)".
shadow-4.8.1/libmisc/copydir.c:752: noescape: Resource "ofd" is not freed or pointed-to in "fchown_if_needed".
shadow-4.8.1/libmisc/copydir.c:775: leaked_handle: Handle variable "ofd" going out of scope leaks the handle.
  773|   	   ) {
  774|   		(void) close (ifd);
  775|-> 		return -1;
  776|   	}
  777|

Error: RESOURCE_LEAK (CWE-772): [#def7]
shadow-4.8.1/libmisc/idmapping.c:188: alloc_fn: Storage is returned from allocation function "xmalloc".
shadow-4.8.1/libmisc/idmapping.c:188: var_assign: Assigning: "buf" = storage returned from "xmalloc(bufsize)".
shadow-4.8.1/libmisc/idmapping.c:188: var_assign: Assigning: "pos" = "buf".
shadow-4.8.1/libmisc/idmapping.c:213: noescape: Resource "buf" is not freed or pointed-to in "write".
shadow-4.8.1/libmisc/idmapping.c:219: leaked_storage: Variable "pos" going out of scope leaks the storage it points to.
shadow-4.8.1/libmisc/idmapping.c:219: leaked_storage: Variable "buf" going out of scope leaks the storage it points to.
  217|   	}
  218|   	close(fd);
  219|-> }

Error: RESOURCE_LEAK (CWE-772): [#def8]
shadow-4.8.1/libmisc/list.c:211: alloc_fn: Storage is returned from allocation function "xstrdup".
shadow-4.8.1/libmisc/list.c:211: var_assign: Assigning: "members" = storage returned from "xstrdup(comma)".
shadow-4.8.1/libmisc/list.c:217: var_assign: Assigning: "cp" = "members".
shadow-4.8.1/libmisc/list.c:218: noescape: Resource "cp" is not freed or pointed-to in "strchr".
shadow-4.8.1/libmisc/list.c:244: leaked_storage: Variable "cp" going out of scope leaks the storage it points to.
shadow-4.8.1/libmisc/list.c:244: leaked_storage: Variable "members" going out of scope leaks the storage it points to.
  242|   	if ('\0' == *members) {
  243|   		*array = (char *) 0;
  244|-> 		return array;
  245|   	}
  246|

Error: RESOURCE_LEAK (CWE-772): [#def11]
shadow-4.8.1/libmisc/myname.c:61: alloc_fn: Storage is returned from allocation function "xgetpwnam".
shadow-4.8.1/libmisc/myname.c:61: var_assign: Assigning: "pw" = storage returned from "xgetpwnam(cp)".
shadow-4.8.1/libmisc/myname.c:67: leaked_storage: Variable "pw" going out of scope leaks the storage it points to.
   65|   	}
   66|
   67|-> 	return xgetpwuid (ruid);
   68|   }
   69|

Error: RESOURCE_LEAK (CWE-772): [#def12]
shadow-4.8.1/libmisc/user_busy.c:260: alloc_fn: Storage is returned from allocation function "opendir".
shadow-4.8.1/libmisc/user_busy.c:260: var_assign: Assigning: "task_dir" = storage returned from "opendir(task_path)".
shadow-4.8.1/libmisc/user_busy.c:262: noescape: Resource "task_dir" is not freed or pointed-to in "readdir".
shadow-4.8.1/libmisc/user_busy.c:278: leaked_storage: Variable "task_dir" going out of scope leaks the storage it points to.
  276|   					         _("%s: user %s is currently used by process %d\n"),
  277|   					         Prog, name, pid);
  278|-> 					return 1;
  279|   				}
  280|   			}

Error: RESOURCE_LEAK (CWE-772): [#def20]
shadow-4.8.1/src/newgrp.c:162: alloc_fn: Storage is returned from allocation function "xgetspnam".
shadow-4.8.1/src/newgrp.c:162: var_assign: Assigning: "spwd" = storage returned from "xgetspnam(pwd->pw_name)".
shadow-4.8.1/src/newgrp.c:234: leaked_storage: Variable "spwd" going out of scope leaks the storage it points to.
  232|   	}
  233|
  234|-> 	return;
  235|
  236|   failure:

Error: RESOURCE_LEAK (CWE-772): [#def21]
shadow-4.8.1/src/passwd.c:530: alloc_fn: Storage is returned from allocation function "xstrdup".
shadow-4.8.1/src/passwd.c:530: var_assign: Assigning: "cp" = storage returned from "xstrdup(crypt_passwd)".
shadow-4.8.1/src/passwd.c:551: noescape: Resource "cp" is not freed or pointed-to in "strlen".
shadow-4.8.1/src/passwd.c:554: noescape: Resource "cp" is not freed or pointed-to in "strcat". [Note: The source code implementation of the function has been overridden by a builtin model.]
shadow-4.8.1/src/passwd.c:555: overwrite_var: Overwriting "cp" in "cp = newpw" leaks the storage that "cp" points to.
  553|   		strcpy (newpw, "!");
  554|   		strcat (newpw, cp);
  555|-> 		cp = newpw;
  556|   	}
  557|   	return cp;
2021-06-24 09:18:35 +02:00
Serge Hallyn
a026ea6bbf
Merge pull request #354 from ikerexxe/useradd_resource_leak
useradd.c: fix covscan RESOURCE_LEAK
2021-06-22 09:22:09 -05:00
Iker Pedrosa
1aed7ae945 useradd.c: fix covscan RESOURCE_LEAK
Error: RESOURCE_LEAK (CWE-772): [#def28]
shadow-4.8.1/src/useradd.c:1905: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/src/useradd.c:1905: var_assign: Assigning: "fd" = handle returned from "open("/var/log/faillog", 2)".
shadow-4.8.1/src/useradd.c:1906: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/useradd.c:1917: leaked_handle: Handle variable "fd" going out of scope leaks the handle.
 1915|   		/* continue */
 1916|   	}
 1917|-> }
 1918|
 1919|   static void lastlog_reset (uid_t uid)

Error: RESOURCE_LEAK (CWE-772): [#def29]
shadow-4.8.1/src/useradd.c:1938: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/src/useradd.c:1938: var_assign: Assigning: "fd" = handle returned from "open("/var/log/lastlog", 2)".
shadow-4.8.1/src/useradd.c:1939: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/useradd.c:1950: leaked_handle: Handle variable "fd" going out of scope leaks the handle.
 1948|   		/* continue */
 1949|   	}
 1950|-> }
 1951|
 1952|   static void tallylog_reset (const char *user_name)

Error: RESOURCE_LEAK (CWE-772): [#def30]
shadow-4.8.1/src/useradd.c:2109: alloc_fn: Storage is returned from allocation function "strdup".
shadow-4.8.1/src/useradd.c:2109: var_assign: Assigning: "bhome" = storage returned from "strdup(prefix_user_home)".
shadow-4.8.1/src/useradd.c:2131: noescape: Resource "bhome" is not freed or pointed-to in "strtok".
shadow-4.8.1/src/useradd.c:2207: leaked_storage: Variable "bhome" going out of scope leaks the storage it points to.
 2205|   		}
 2206|   #endif
 2207|-> 	}
 2208|   }
 2209|
2021-06-15 09:40:40 +02:00
Iker Pedrosa
8281c82e32 usermod.c: fix covscan RESOURCE_LEAK
Error: RESOURCE_LEAK (CWE-772): [#def31]
shadow-4.8.1/src/usermod.c:813: alloc_fn: Storage is returned from allocation function "__gr_dup".
shadow-4.8.1/src/usermod.c:813: var_assign: Assigning: "ngrp" = storage returned from "__gr_dup(grp)".
shadow-4.8.1/src/usermod.c:892: leaked_storage: Variable "ngrp" going out of scope leaks the storage it points to.
  890|   		}
  891|   	}
  892|-> }
  893|
  894|   #ifdef SHADOWGRP

Error: RESOURCE_LEAK (CWE-772): [#def32]
shadow-4.8.1/src/usermod.c:933: alloc_fn: Storage is returned from allocation function "__sgr_dup".
shadow-4.8.1/src/usermod.c:933: var_assign: Assigning: "nsgrp" = storage returned from "__sgr_dup(sgrp)".
shadow-4.8.1/src/usermod.c:1031: leaked_storage: Variable "nsgrp" going out of scope leaks the storage it points to.
 1029|   		}
 1030|   	}
 1031|-> }
 1032|   #endif				/* SHADOWGRP */
 1033|

Error: RESOURCE_LEAK (CWE-772): [#def34]
shadow-4.8.1/src/usermod.c:1161: alloc_fn: Storage is returned from allocation function "getgr_nam_gid".
shadow-4.8.1/src/usermod.c:1161: var_assign: Assigning: "grp" = storage returned from "getgr_nam_gid(optarg)".
shadow-4.8.1/src/usermod.c:1495: leaked_storage: Variable "grp" going out of scope leaks the storage it points to.
 1493|   	}
 1494|   #endif				/* ENABLE_SUBIDS */
 1495|-> }
 1496|
 1497|   /*

Error: RESOURCE_LEAK (CWE-772): [#def35]
shadow-4.8.1/src/usermod.c:1991: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/src/usermod.c:1991: var_assign: Assigning: "fd" = handle returned from "open("/var/log/lastlog", 2)".
shadow-4.8.1/src/usermod.c:2000: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/usermod.c:2000: noescape: Resource "fd" is not freed or pointed-to in "read". [Note: The source code implementation of the function has been overridden by a builtin model.]
shadow-4.8.1/src/usermod.c:2003: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/usermod.c:2032: leaked_handle: Handle variable "fd" going out of scope leaks the handle.
 2030|   		}
 2031|   	}
 2032|-> }
 2033|
 2034|   /*

Error: RESOURCE_LEAK (CWE-772): [#def36]
shadow-4.8.1/src/usermod.c:2052: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/src/usermod.c:2052: var_assign: Assigning: "fd" = handle returned from "open("/var/log/faillog", 2)".
shadow-4.8.1/src/usermod.c:2061: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/usermod.c:2061: noescape: Resource "fd" is not freed or pointed-to in "read". [Note: The source code implementation of the function has been overridden by a builtin model.]
shadow-4.8.1/src/usermod.c:2064: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/usermod.c:2092: leaked_handle: Handle variable "fd" going out of scope leaks the handle.
 2090|   		}
 2091|   	}
 2092|-> }
 2093|
 2094|   #ifndef NO_MOVE_MAILBOX
2021-06-11 11:50:49 +02:00
Serge Hallyn
9d37173b24 usermod, newusers, prefix: enforce absolute paths for homedir
useradd already was enforcing this, but these were not.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-06-01 22:12:24 -05:00
Serge Hallyn
8eb6f8ace4
Merge pull request #327 from squat/bugfix_relative_prefix_path
fix: create relative home path correctly
2021-05-29 14:16:46 -05:00
Serge Hallyn
9d169ffc41 fix newusers when nss provides subids
Closes #331

1. drop 'has_any_range' nss method as it is not useful

2. do not try to create a subid range in newusers when using nss for
   subids, since that's not possible.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
(cherry picked from commit 88a434adbdcf4a8640793fd58bcd2ba77598349d)
2021-05-23 08:16:16 -05:00
Serge Hallyn
ea7af4e154
Merge pull request #340 from hallyn/2021-05-16/subidrange
Don't return owner in list_owner_ranges API call.
2021-05-22 18:16:43 -05:00
Serge Hallyn
3d670ba7ed nss/libsubid: simplify the ranges variable for list_owner_ranges
Following alexey-tikhonov's suggestion.

Since we've dropped the 'owner' field in the data returned for
get_subid_ranges, we can just return a single allocated array of
simple structs.  This means we can return a ** instead of ***, and
we can get rid of the subid_free_ranges() helper, since the caller
can just free() the returned data.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-22 17:59:57 -05:00
Serge Hallyn
663824ef4c Fix useradd with SUB_UID_COUNT=0
Closes #298

Fix useradd when SUB_UID_COUNT=0 in login.defs.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-22 11:42:02 -05:00
Serge Hallyn
322db32971 Don't return owner in list_owner_ranges API call.
Closes: 339

struct subordinate_range is pretty closely tied to the existing
subid code and /etc/subuid format, so it includes an owner.  Dropping
that or even renaming it is more painful than I'd first thought.
So introduce a 'struct subid_range' which is only the start and
count, leaving 'struct subordinate_range' as the owner, start and
count.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-16 21:49:53 -05:00
Serge Hallyn
2b22a6909d libsubid: don't print error messages on stderr by default
Closes #325

Add a new subid_init() function which can be used to specify the
stream on which error messages should be printed.  (If you want to
get fancy you can redirect that to memory :)  If subid_init() is
not called, use stderr.  If NULL is passed, then /dev/null will
be used.

This patch also fixes up the 'Prog', which previously had to be
defined by any program linking against libsubid.  Now, by default
in libsubid it will show (subid).  Once subid_init() is called,
it will use the first variable passed to subid_init().

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-15 12:38:55 -05:00
Christian Göttsche
eb1d2de0e9 set_selinux_file_context(): prepare context for actual file type
Search the SELinux selabel database for the file type to be created.
Not specifying the file mode can cause an incorrect file context to be
returned.

Also prepare contexts in commonio_close() for the generic database
filename, not with the backup suffix appended, to ensure the desired
file context after the final rename.

Closes: #322

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: James Carter <jwcart2@gmail.com>
2021-05-06 16:58:10 +02:00
Christian Göttsche
c0aa8a876e vipw[selinux]: do not use deprecated typedef and skip context translation
This retrieved context is just passed to libselinux functions and not
printed or otherwise made available to the outside, so a context
translation to human readable MCS/MLS labels is not needed.
(see man:setrans.conf(5))

The typedef security_context_t is deprecated, see
9eb9c93275

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: James Carter <jwcart2@gmail.com>
2021-05-06 16:58:10 +02:00
Christian Göttsche
6e4b2fe25d struct commonio_db[selinux]: do not use deprecated type security_context_t
The typedef security_context_t is deprecated, see
9eb9c93275

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: James Carter <jwcart2@gmail.com>
2021-05-06 16:58:10 +02:00
Lucas Servén Marín
2c542f6c65
fix: create relative home path correctly
Currently, supplying a relative path via the --prefix flag to the
useradd command triggers a bug in the creation of home directories. The
code seems to unintentionally prepend a leading "/" to all paths,
quietly transforming a relative prefixed home path into an absolute
path. This can be seen in the following strace logs from running
"useradd --create-home --prefix tmp/root squat":

```
access("tmp/root//home/squat", F_OK)    = -1 ENOENT (No such file or directory)
access("/mp", F_OK)                     = 0
access("/mp/root", F_OK)                = 0
access("/mp/root/home", F_OK)           = 0
access("/mp/root/home/squat", F_OK)     = -1 ENOENT (No such file or directory)
mkdir("/mp/root/home/squat", 000)       = 0
chown("/mp/root/home/squat", 0, 0)      = 0
chmod("/mp/root/home/squat", 0755)      = 0
chown("tmp/root//home/squat", 1000, 1000) = -1 ENOENT (No such file or directory)
chmod("tmp/root//home/squat", 0700)     = -1 ENOENT (No such file or directory)
```

Note that the relative path is correctly probed in the beginning and it
is only during the recursive creation that the path is turned into an
absolute path. This invocation results in the creation of a "/mp"
hierarchy in the root of the filesystem.

Similar problems occur when using `--prefix ./tmp/root`.

This commit fixes the handling of relative paths by not assuming that
the given path is anchored with a "/".

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>
2021-04-29 15:06:53 +02:00
Serge Hallyn
0f4347d148 clean up libsubid headers
Move libsubid/api.h into libsubid/subid.h, and document the api in subid.h

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-04-16 21:03:08 -05:00
Serge Hallyn
8492dee663 subids: support nsswitch
Closes #154

When starting any operation to do with subuid delegation, check
nsswitch for a module to use.  If none is specified, then use
the traditional /etc/subuid and /etc/subgid files.

Currently only one module is supported, and there is no fallback
to the files on errors.  Several possibilities could be considered:

1. in case of connection error, fall back to files
2. in case of unknown user, also fall back to files

etc...

When non-files nss module is used, functions to edit the range
are not supported.  It may make sense to support it, but it also
may make sense to require another tool to be used.

libsubordinateio also uses the nss_ helpers.  This is how for instance
lxc could easily be converted to supporting nsswitch.

Add a set of test cases, including a dummy libsubid_zzz module.  This
hardcodes values such that:

'ubuntu' gets 200000 - 300000
'user1' gets 100000 - 165536
'error' emulates an nss module error
'unknown' emulates a user unknown to the nss module
'conn' emulates a connection error ot the nss module

Changes to libsubid:

Change the list_owner_ranges api: return a count instead of making the array
null terminated.

This is a breaking change, so bump the libsubid abi major number.

Rename free_subuid_range and free_subgid_range to ungrant_subuid_range,
because otherwise it's confusing with free_subid_ranges which frees
    memory.

Run libsubid tests in jenkins

Switch argument order in find_subid_owners

Move the db locking into subordinateio.c

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-04-16 21:02:37 -05:00
Serge Hallyn
514c1328b6 try again to fix libmisc sharing problem
Issue #297 reported seeing

*** Warning: Linking the shared library libsubid.la against the
*** static library ../libmisc/libmisc.a is not portable!

which commit b5fb1b38ee was supposed
to fix.  But a few commits later it's back.  So try to fix it
in the way the bug reporter suggested.  This broke builds some
other ways, namely a few missing library specifications, so add
those.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-04-11 17:42:04 -05:00
Haelwenn Monnier
b865e14f25
login & su: Treat an empty passwd field as invalid (#315)
* login & su: Treat an empty passwd field as invalid

Otherwise it's treated like the “require no password” clause while it probably
should be treated like a normal su that can't validate anyway.

A similar change should be done for USE_PAM.

* su & login: Introduce PREVENT_NO_AUTH
2021-03-28 22:16:03 -05:00
Serge Hallyn
697901a328
Merge pull request #303 from breard-r/yescrypt
Add yescrypt support
2021-03-28 22:13:56 -05:00
Serge Hallyn
7273c25cc2
Merge pull request #308 from martijndegouw/relaxgidcheck
newuidmap,newgidmap: Relax gid checking to allow running under alternative group ID
2021-03-02 12:42:25 -06:00
ikerexxe
0409c91a7f userdel: clarify "-f" usage
src/userdel.c: clarify the examples for "-f" option
2021-02-23 12:21:42 +01:00
Martijn de Gouw
c464ec5570 newuidmap,newgidmap: Relax gid checking to allow running under alternative group ID
Signed-off-by: Martijn de Gouw <martijn.de.gouw@prodrive-technologies.com>
2021-02-08 13:32:18 +01:00
Geert Ijewski
fe159b7668 usermod: check if shell exists & is executable 2021-02-07 19:26:55 +01:00
Rodolphe Bréard
5cd04d03f9 Add yescrypt support 2021-02-01 22:11:10 +01:00
Serge Hallyn
0dffc7c612 useradd: don't try to create 0 subuids
Closes #289

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-01-01 13:10:12 -06:00