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out-of-date.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.
* lib/groupmem.c (__gr_dup): Support libc which define other
fields in struct group.
* lib/pwmem.c: Likewise for struct passwd.
* lib/shadowmem.c: Likewise for struct spwd.
* lib/sgroupio.c: Apply same logic, even if this structure is
defined internally.
Serge Hallyn [Fri, 21 Jun 2013 16:47:36 +0000 (11:47 -0500)]
userns: add argument sanity checking
In find_new_sub_{u,g}ids, check for min, count and max values.
In idmapping.c:get_map_ranges(), make sure that the value passed
in for ranges did not overflow. Couldn't happen with the current
code, but this is a sanity check for any future potential mis-uses.
Serge Hallyn [Thu, 6 Jun 2013 15:42:36 +0000 (17:42 +0200)]
subordinateio: Fix subordinate_parse to have an internal static buffer
subordinate_parse is supposed to return a static structure that
represents one line in /etc/subuid or /etc/subgid. I goofed and
failed to make the variable rangebuf that holds the username of
in the returned structure static.
Add this missing static specification.
Author: <Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
These files list the set of subordinate uids and gids that users are allowed
to use. The expect use case is with the user namespace but other uses are
allowed.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* libmisc/salt.c: random() max value is 2^31-1 (same as RAND_MAX
on GNU). As it is not clear whether on some systems the max value
can exceed this number and whether some systems have max values
which would be lower, we take this into account when defining the
salt size and number of rounds for SHA encrypted passwords. Higher
values are favored.
* man/su.1.xml: With getopt, '-' does not need to be the last
option, but it is recommended for portability.
Closes https://bugs.launchpad.net/bugs/1100775
Review b10cba0e0af5b1e3e8cda0201d5563f085aab2a4 and 7a16f4582da2b854a0adcba445bf6f8d750b2919:
* lib/groupio.c (merge_group_entries): Do not allocate more than
necessary (sizeof char* instead of char).
Thanks for Tomáš Mráz (alioth#313962)
* lib/groupio.c (merge_group_entries): Document that new_members
is correctly NULL terminated. (alioth:#313940)
* Changelog: Update documentation of 2013-07-28 mancha entry.
* lib/prototypes.h, lib/encrypt.c: Update splint marker,
pw_encrypt can return NULL.
* lib/encrypt.c: Fix outdated statement on GNU crypt.
* src/chgpasswd.c: Improve diagnostic to user when pw_encrypt
fails and use fail_exit() instead of exit().
* src/chpasswd.c: Likewise.
* src/newusers.c: Likewise.
* src/passwd.c: Likewise when new password is encrypted.
* src/newgrp.c: Improve diagnostic to user and syslog when
pw_encrypt fails. Do not apply 1s penalty as this is not an
invalid password issue.
* src/passwd.c: Likewise when password is checked.
* libmisc/setupenv.c: xstrdup the static char* temp_pw_dir /
temp_pw_shell. That way we can continue to use pw_free() without
segving. Thanks to Serge Hallyn for the patch.
crypt() in glibc/eglibc 2.17 now fails if passed
a salt that violates specs. On Linux, crypt() also fails with
DES/MD5 salts in FIPS140 mode. Rather than exit() on NULL returns
we send them back to the caller for appropriate handling.
Colin Watson [Sun, 28 Jul 2013 12:38:12 +0000 (14:38 +0200)]
Kill the child process group, rather than just the immediate child;
this is needed now that su no longer starts a controlling terminal
when not running an interactive shell (closes: Debian#713979)
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