From: Pádraig Brady Date: Wed, 8 Apr 2009 09:43:15 +0000 (+0100) Subject: id: fix infinite loop on some systems X-Git-Tag: v7.3~47 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf87a2c8ea4487ca4448c9fe42a9c9858400acbd;p=thirdparty%2Fcoreutils.git id: fix infinite loop on some systems Steven Parkes reported that `id -G $USER` went into an infinite loop on Darwin systems for users in more than 10 groups: http://bugs.gentoo.org/show_bug.cgi?id=264007 * gl/lib/mgetgroups.c (mgetgroups): Work around buggy getgrouplist implementations that don't update the required size correctly, by doubling the result buffer and retrying. Also return the parameter updated by getgrouplist rather than its return value, as the documentation doesn't actually state the number of groups stored is returned by getgrouplist. * tests/misc/id-groups: Add test to exercise this logic * tests/Makefile.am: Reference new test * NEWS: Mention the fix * THANKS: Update --- diff --git a/NEWS b/NEWS index de1db44375..a116b646ca 100644 --- a/NEWS +++ b/NEWS @@ -14,6 +14,14 @@ GNU coreutils NEWS -*- outline -*- default should proceed at the speed of the disk. Previously /dev/urandom was used if available, which is relatively slow on GNU/Linux systems. +** Portability + + `id -G $USER` now works correctly even on Darwin and NetBSD. Previously it + would either truncate the group list to 10, or go into an infinite loop, + due to their non-standard getgroups implementations. + [truncation introduced in coreutils-6.11] + [infinite loop introduced in coreutils-7.1] + * Noteworthy changes in release 7.2 (2009-03-31) [stable] ** New features diff --git a/THANKS b/THANKS index 6a918a4297..fe523fe12b 100644 --- a/THANKS +++ b/THANKS @@ -525,6 +525,7 @@ Steve McIntyre steve@einval.com Steve Ward planet36@gmail.com Steven G. Johnson stevenj@alum.mit.edu Steven Mocking ufo@quicknet.nl +Steven Parkes smparkes@smparkes.net Steven Schveighoffer schveiguy@yahoo.com Steven P Watson steven@magelico.net Stuart Kemp skemp@peter.bmc.com diff --git a/gl/lib/mgetgroups.c b/gl/lib/mgetgroups.c index e697013ef0..736dd87f38 100644 --- a/gl/lib/mgetgroups.c +++ b/gl/lib/mgetgroups.c @@ -81,10 +81,16 @@ mgetgroups (char const *username, gid_t gid, GETGROUPS_T **groups) while (1) { GETGROUPS_T *h; + int last_n_groups = max_n_groups; /* getgrouplist updates max_n_groups to num required. */ ng = getgrouplist (username, gid, g, &max_n_groups); + /* Some systems (like Darwin) have a bug where they + never increase max_n_groups. */ + if (ng < 0 && last_n_groups == max_n_groups) + max_n_groups *= 2; + if ((h = realloc_groupbuf (g, max_n_groups)) == NULL) { int saved_errno = errno; @@ -97,7 +103,9 @@ mgetgroups (char const *username, gid_t gid, GETGROUPS_T **groups) if (0 <= ng) { *groups = g; - return ng; + /* On success some systems just return 0 from getgrouplist, + so return max_n_groups rather than ng. */ + return max_n_groups; } } } diff --git a/tests/Makefile.am b/tests/Makefile.am index 07f34ec450..8ce6a2118f 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -171,6 +171,7 @@ TESTS = \ misc/head-c \ misc/head-pos \ misc/id-context \ + misc/id-groups \ misc/md5sum \ misc/md5sum-newline \ misc/mknod \ diff --git a/tests/misc/id-groups b/tests/misc/id-groups new file mode 100755 index 0000000000..dc0f54c294 --- /dev/null +++ b/tests/misc/id-groups @@ -0,0 +1,28 @@ +#!/bin/sh +# Ensure that "id" outputs groups for a user +# Copyright (C) 2009 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 . + +if test "$VERBOSE" = yes; then + set -x + id --version +fi + +. $srcdir/test-lib.sh + +fail=0 +id -G $(id -nu) || fail=1 + +Exit $fail