The current implementation of subuid/subgid support in usermod requires the
user to be a local user present in /etc/passwd. There doesn't seem to be a
good reason for this; subuids should work equally well for users whose
records are in other NSS databases.
The functions __gr_dup and __pw_dup do not explicitly zero the
memory which hold the passwords after free. The gr_free and pw_free
functions do this explicitly.
To guarantee same behaviour, it's possible to call these *_free
functions directly from __*_dup, because the memory is initialized
with zeros at the beginning. Calling free(NULL) has no negative
effect and can be considered safe these days.
Allow deleting the group even if it is the primary group of a user
This is helpful when using configuration management tools such as
Puppet, where you are managing the groups in a central location and you
don't need this safeguard.
Signed-off-by: "Jesse W. Hathaway" <jesse@mbuki-mvuki.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Expand the error message when newuidmap / newgidmap do not like the user/group ownership of their target process.
Currently the error is just:
newuidmap: Target [pid] is owned by a different user
With this patch it will be like:
newuidmap: Target [pid] is owned by a different user: uid:0 pw_uid:0 st_uid:0, gid:0 pw_gid:0 st_gid:99
Why is this useful? Well, in my case...
The grsecurity kernel-hardening patch includes an option to make parts
of /proc unreadable, such as /proc/pid/ dirs for processes not owned by
the current uid. This comes with an option to make /proc/pid/
directories readable by a specific gid; sysadmins and the like are then
put into that group so they can see a full 'ps'.
This means that the check in new[ug]idmap fails, as in the above quoted
error - /proc/[targetpid] is owned by root, but the group is 99 so that
users in group 99 can see the process.
Some Googling finds dozens of people hitting this problem, but not
*knowing* that they have hit this problem, because the errors and
circumstances are non-obvious.
Some graceful way of handling this and not failing, will be next ;) But
in the meantime it'd be nice to have new[ug]idmap emit a more useful
error, so that it's easier to troubleshoot.
Do not fail on missing files in /etc/, create them instead.
passwd, shadow, group, gshadow etc. can be managed via nss -
e.g. system default accounts can be specified using nss_altfiles,
rather than in /etc/. Thus despite having default accounts, these
files can be missing on disk and thus should be opened with O_CREATE
whenever they are attempted to be opened in O_RDWR modes.
Do not report unknown settings, when compiled with PAM.
When compiled with PAM certain settings are not used, however they are
still defined in the stock login.defs file. Thus every command reports
them as "unknown setting contact administrator".
Alternative would be to parse stock login.defs and comment out/remove
settings that are not applied, when compiled with PAM.
Duncan Eastoe [Mon, 9 Feb 2015 14:39:31 +0000 (14:39 +0000)]
Suppress pwconv passwd- chmod failure message
Prevent chmod failure message from displaying if the failure
was due to the backup file not existing.
If there is no backup file present and if no changes have been
made, then this error would always appear since the backup
file isn't created in this situation.
sub[ug]id: compare range before comparing username/UID, to avoid unnecessary syscalls
Change suggested by Nicolas François as performance optimization.
Performance penalty would be really noticeable when usernames are
stored in remote databases (ldap).
newuidmap/newgidmap: added support for user matching by UID in /etc/sub[ug]id
Until now only exact username specification in /etc/sub[ug]id file allowed the
mapping. This prevented normal use for those users who use multiple usernames
with the same UID, as it rejected mapping even though it was allowed for
another username with the same UID.
This patch initially retains the old behaviour, for performance's sake. In the
first pass, new[ug]idmap only searches for exact username match.
If that yields no valid results, it continues into another loop, which does UID
resolution and comparison. If either definition (numeric UID mapping
specification or mapping specification for another username with the same UID as
current username) is found, it is used.
Serge Hallyn [Thu, 26 Jun 2014 21:48:56 +0000 (16:48 -0500)]
From: Svante Signell <svante.signell@gmail.com>
Currently shadow fails to build from source and is flagged as
out-of-date. This is due to a usage of PATH_MAX, which is not defined
on GNU/Hurd. The attached patch solves this problem by allocating a
fixed number of 32 bytes for the string proc_dir_name in files
src/procuidmap.c and src/procgidmap.c. (In fact only 18 bytes are
needed)
Serge Hallyn [Mon, 9 Jun 2014 22:37:16 +0000 (17:37 -0500)]
man: newuid and newgid: point out that root must be allocated subuids
Users may otherwise be confused and think that because the kernel
does not restrict uid mappings to the root user (within his
current uid mappings), newuidmap will ignore /etc/subuid for the
root user. It will not.
Reported-by: Philippe Grégoire <gregoirep@hotmail.com> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Nicolas François [Thu, 15 Aug 2013 15:21:44 +0000 (17:21 +0200)]
Improve documentation.
* man/login.defs.d/SUB_GID_COUNT.xml: Document newusers behavior
when the user already have subordinate group IDs.
* man/login.defs.d/SUB_UID_COUNT.xml: Likewise.
* man/login.defs.d/SUB_GID_COUNT.xml: Fix typo (MAX<->MIN).
* man/login.defs.d/SUB_UID_COUNT.xml: Likewise.
Nicolas François [Thu, 15 Aug 2013 14:46:51 +0000 (16:46 +0200)]
Remove dead code.
* libmisc/find_new_sub_gids.c: Remove dead code.
find_new_sub_gids() is always called with *range_count set to 0.
It's more difficult to keep the subordinate GIDs and UIDs
synchronized, than for the user's UID/GId because the count of
subordinate IDs may differ.
* libmisc/find_new_sub_uids.c: Likewise.
* lib/subordinateio.h, lib/subordinateio.c: Remove APIs that are
no more needed: is_sub_uid_range_free(), is_sub_gid_range_free(),
is_range_free().
Nicolas François [Tue, 13 Aug 2013 17:48:53 +0000 (19:48 +0200)]
Terminate the child before closing the PAM session.
* src/su.c: Terminate the child (if needed) before closing the PAM
session. This is probably more correct, and avoid reporting
termination from signals possibly sent by PAM modules (e.g. former
versions of pam_systemd). Debian#670132
Nicolas François [Tue, 13 Aug 2013 17:42:50 +0000 (19:42 +0200)]
Reset caught variable when signal is handled by su.
* src/su.c: When a SIGTSTP is caught, reset caught to 0. There is
no need to kill the child in such case after su is resumed. This
remove the "Session terminated, terminating shell...
...terminated." messages in such case.
Nicolas François [Tue, 13 Aug 2013 17:28:07 +0000 (19:28 +0200)]
Document the semantic of ranges.
* libmisc/idmapping.h: Document what the upper and lower fields
are in struct map_range.
* man/newgidmap.1.xml: Document when the gid, gidlower and count
argument are.
* man/newuidmap.1.xml: Likewise for uid, uidlower and count.
Nicolas François [Tue, 13 Aug 2013 17:16:24 +0000 (19:16 +0200)]
(shadow_random): Use long instead of size_t.
* libmisc/salt.c (shadow_random): Use long instead of size_t.
Compatibility with size_t is easier to check since it's used for
smaller numbers (salt size).
Nicolas François [Mon, 12 Aug 2013 22:21:02 +0000 (00:21 +0200)]
Improve documentation.
* man/login.defs.d/SUB_GID_COUNT.xml: Document that the behavior
of useradd and newusers depends on the existence of /etc/subgid.
* man/login.defs.d/SUB_UID_COUNT.xml: Likewise for /etc/subuid.
Nicolas François [Mon, 12 Aug 2013 22:13:12 +0000 (00:13 +0200)]
Improve error reporting.
* src/useradd.c: Change message in case of find_new_sub_uids /
find_new_sub_gids failure. This complements the messages already
provided by these APIs.
Nicolas François [Sun, 11 Aug 2013 12:54:22 +0000 (14:54 +0200)]
Allow disabling of subordinate IDs.
* configure.in: Add configure options --enable-subordinate-ids /
--disable-subordinate-ids. Enabled by default.
* lib/prototypes.h: Include <config.h> before using its macros.
* lib/commonio.h, lib/commonio.c: Define commonio_append only when
ENABLE_SUBIDS is defined.
* lib/prototypes.h, libmisc/find_new_sub_gids.c,
libmisc/find_new_sub_uids.c: Likewise.
* lib/subordinateio.h, lib/subordinateio.c: Likewise.
* libmisc/user_busy.c: Only check if subordinate IDs are in use if
ENABLE_SUBIDS is defined.
* src/Makefile.am: Create newgidmap and newuidmap only if
ENABLE_SUBIDS is defined.
* src/newusers.c: Check for ENABLE_SUBIDS to enable support for
subordinate IDs.
* src/useradd.c: Likewise.
* src/userdel.c: Likewise.
* src/usermod.c: Likewise.
* man/Makefile.am: Install man1/newgidmap.1, man1/newuidmap.1,
man5/subgid.5, and man5/subuid.5 only if ENABLE_SUBIDS is defined.
* man/fr/Makefile.am: Install man1/newgidmap.1, man1/newuidmap.1,
man5/subgid.5, and man5/subuid.5 (not translated yet).
* man/generate_mans.mak: Add xsltproc conditionals
subids/no_subids.
* man/login.defs.d/SUB_GID_COUNT.xml: Add dependency on subids
condition.
* man/login.defs.d/SUB_UID_COUNT.xml: Likewise.
* man/usermod.8.xml: Document options for subordinate IDs and
reference subgid(5) / subuid(5) depending on the subids condition.
Mike Frysinger [Tue, 6 Aug 2013 23:44:24 +0000 (01:44 +0200)]
check for ruserok existence
rlogin support is old school code, so newer C libraries drop support for
ruserok (like uClibc, optionally). But shadow doesn't build with that,
so have it check for ruserok to optionally enable rlogin.
projects / shadow / log