commit 032a549481444395558286b433296c97c09c721d Author: Jim Meyering Date: Fri Apr 27 13:28:32 2012 +0200 id,groups: with no user name, print only real and/or effective IDs, ... i.e., don't use the getpw* functions. Before this change, running groups or id with no user name argument would include a group name or ID from /etc/passwd. Thus, under unusual circumstances (default group is changed, but has not taken effect for a given session), those programs could print a name or ID that is neither real nor effective. To demonstrate, run this: echo 'for i in 1 2; do id -G; sleep 1.5; done' \ |su -s /bin/sh ftp - & sleep 1; perl -pi -e 's/^(ftp:x:\d+):(\d+)/$1:9876/' /etc/passwd Those id -G commands printed the following: 50 50 9876 With this change, they print this: 50 50 Similarly, running those programs set-GID could make them print one ID too many. * src/group-list.c (print_group_list): When username is NULL, pass egid, not getpwuid(ruid)->pw_gid), to xgetgroups, per the API requirements of xgetgroups callee, mgetgroups. When not using the password database, don't call getpwuid. * NEWS (Bug fixes): Mention it. * tests/misc/id-setgid: New file. * tests/Makefile.am (TESTS): Add it. (root_tests): It's a root-only test, so add it here, too. Originally reported by Brynnen Owen as http://bugs.gnu.org/7320. Raised again by Marc Mengel in http://bugzilla.redhat.com/816708. Index: NEWS =================================================================== --- NEWS.orig 2012-03-26 14:06:43.000000000 +0200 +++ NEWS 2012-05-07 14:20:23.431517270 +0200 @@ -1,5 +1,15 @@ GNU coreutils NEWS -*- outline -*- +** Bug fixes + + id and groups, when invoked with no user name argument, would print + the default group ID listed in the password database, and sometimes + that ID would be neither real nor effective. For example, when run + set-GID, or in a session for which the default group has just been + changed, the new group ID would be listed, even though it is not + yet effective. + + * Noteworthy changes in release 8.16 (2012-03-26) [stable] ** New features Index: THANKS.in =================================================================== --- THANKS.in.orig 2012-03-24 19:22:13.000000000 +0100 +++ THANKS.in 2012-05-07 14:19:38.953620833 +0200 @@ -98,6 +98,7 @@ Brian Silverman bsil Brian Youmans 3diff@gnu.org Britton Leo Kerin fsblk@aurora.uaf.edu Bruce Robertson brucer@theodolite.dyndns.org +Brynnen Owen owen@illinois.edu Carl Johnson carlj@cjlinux.home.org Carl Lowenstein cdl@mpl.UCSD.EDU Carl Roth roth@urs.us @@ -355,6 +356,7 @@ Manfred Hollstein manf Марк Коренберг socketpair@gmail.com Marc Boucher marc@mbsi.ca Marc Haber mh+debian-bugs@zugschlus.de +Marc Mengel mengel@fnal.gov Marc Lehman schmorp@schmorp.de Marc Olzheim marcolz@stack.nl Marco Franzen Marco.Franzen@Thyron.com Index: src/group-list.c =================================================================== --- src/group-list.c.orig 2012-02-03 14:16:13.000000000 +0100 +++ src/group-list.c 2012-05-07 14:19:38.953620833 +0200 @@ -38,11 +38,14 @@ print_group_list (const char *username, bool use_names) { bool ok = true; - struct passwd *pwd; + struct passwd *pwd = NULL; - pwd = getpwuid (ruid); - if (pwd == NULL) - ok = false; + if (username) + { + pwd = getpwuid (ruid); + if (pwd == NULL) + ok = false; + } if (!print_group (rgid, use_names)) ok = false; @@ -58,8 +61,7 @@ print_group_list (const char *username, gid_t *groups; int i; - int n_groups = xgetgroups (username, (pwd ? pwd->pw_gid : (gid_t) -1), - &groups); + int n_groups = xgetgroups (username, (pwd ? pwd->pw_gid : egid), &groups); if (n_groups < 0) { if (username) Index: tests/Makefile.am =================================================================== --- tests/Makefile.am.orig 2012-05-07 14:19:38.807624454 +0200 +++ tests/Makefile.am 2012-05-07 14:19:38.953620833 +0200 @@ -36,6 +36,7 @@ root_tests = \ ls/nameless-uid \ misc/chcon \ misc/chroot-credentials \ + misc/id-setgid \ misc/selinux \ misc/truncate-owned-by-other \ mkdir/writable-under-readonly \ @@ -197,6 +198,7 @@ TESTS = \ misc/head-pos \ misc/id-context \ misc/id-groups \ + misc/id-setgid \ misc/md5sum \ misc/md5sum-bsd \ misc/md5sum-newline \ Index: tests/misc/id-setgid =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ tests/misc/id-setgid 2012-05-07 14:19:38.953620833 +0200 @@ -0,0 +1,34 @@ +#!/bin/sh +# Verify that id -G prints the right group when run set-GID. + +# Copyright (C) 2012 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +. "${srcdir=.}/init.sh"; path_prepend_ ../src +print_ver_ id +require_root_ + +g=$(id -u $NON_ROOT_USERNAME) || framework_failure_ + +# Construct a different group number. +gp1=$(expr $g + 1) + +echo $gp1 > exp || framework_failure_ + +setuidgid -g $gp1 $NON_ROOT_USERNAME env PATH="$PATH" id -G > out || fail=1 +compare exp out || fail=1 +# With coreutils-8.16 and earlier, id -G would print both: $gp1 $g + +Exit $fail