freebsd-dev/module/spl/spl-cred.c
Brian Behlendorf e19101e08f splat cred:groupmember: Fix false positives
Due to certain assumptions made in the the cred:groupmember test it
could result in false positives when run on specific distributions.
This was solely a bug in the test case and not in the groupmember()
function which the test case was validating.

To prevent future false positives the test case has been rewritten
to be both more rigerous and to make fewer assumptions about the
system.

Minor style cleanup was done to cr_groups_search() and groupmember()
functions.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2014-04-08 12:44:41 -07:00

290 lines
6.3 KiB
C

/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL 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 2 of the License, or (at your
* option) any later version.
*
* The SPL 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 the SPL. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************
* Solaris Porting Layer (SPL) Credential Implementation.
\*****************************************************************************/
#include <sys/cred.h>
#ifdef DEBUG_SUBSYSTEM
#undef DEBUG_SUBSYSTEM
#endif
#define DEBUG_SUBSYSTEM S_CRED
#ifdef HAVE_GROUPS_SEARCH
/* Symbol may be exported by custom kernel patch */
#define cr_groups_search(gi, grp) groups_search(gi, grp)
#else
/* Implementation from 2.6.30 kernel */
static int
#ifdef HAVE_KUIDGID_T
cr_groups_search(const struct group_info *group_info, kgid_t grp)
#else
cr_groups_search(const struct group_info *group_info, gid_t grp)
#endif
{
unsigned int left, right, mid;
int cmp;
if (!group_info)
return 0;
left = 0;
right = group_info->ngroups;
while (left < right) {
mid = (left + right) / 2;
cmp = KGID_TO_SGID(grp) -
KGID_TO_SGID(GROUP_AT(group_info, mid));
if (cmp > 0)
left = mid + 1;
else if (cmp < 0)
right = mid;
else
return 1;
}
return 0;
}
#endif
#ifdef HAVE_CRED_STRUCT
/*
* As of 2.6.29 a clean credential API appears in the linux kernel.
* We attempt to layer the Solaris API on top of the linux API.
*/
/* Hold a reference on the credential and group info */
void
crhold(cred_t *cr)
{
(void)get_cred((const cred_t *)cr);
(void)get_group_info(cr->group_info);
}
/* Free a reference on the credential and group info */
void
crfree(cred_t *cr)
{
put_group_info(cr->group_info);
put_cred((const cred_t *)cr);
}
/* Return the number of supplemental groups */
int
crgetngroups(const cred_t *cr)
{
struct group_info *gi;
int rc;
gi = get_group_info(cr->group_info);
rc = gi->ngroups;
put_group_info(gi);
return rc;
}
/*
* Return an array of supplemental gids. The returned address is safe
* to use as long as the caller has taken a reference with crhold().
* The caller is responsible for releasing the reference with crfree().
*/
gid_t *
crgetgroups(const cred_t *cr)
{
struct group_info *gi;
gid_t *gids;
gi = get_group_info(cr->group_info);
gids = KGIDP_TO_SGIDP(gi->blocks[0]);
put_group_info(gi);
return gids;
}
/* Check if the passed gid is available in supplied credential. */
int
groupmember(gid_t gid, const cred_t *cr)
{
struct group_info *gi;
int rc;
gi = get_group_info(cr->group_info);
rc = cr_groups_search(gi, SGID_TO_KGID(gid));
put_group_info(gi);
return rc;
}
#else /* HAVE_CRED_STRUCT */
/*
* Until very recently all credential information was embedded in
* the linux task struct. For this reason to simulate a Solaris
* cred_t we need to pass the entire task structure around.
*/
/* Hold a reference on the credential and group info */
void crhold(cred_t *cr) { }
/* Free a reference on the credential and group info */
void crfree(cred_t *cr) { }
/* Return the number of supplemental groups */
int
crgetngroups(const cred_t *cr)
{
int lock, rc;
lock = (cr != current);
if (lock)
task_lock((struct task_struct *)cr);
get_group_info(cr->group_info);
rc = cr->group_info->ngroups;
put_group_info(cr->group_info);
if (lock)
task_unlock((struct task_struct *)cr);
return rc;
}
/*
* Return an array of supplemental gids. The returned address is safe
* to use as long as the caller has taken a reference with crhold().
* The caller is responsible for releasing the reference with crfree().
*/
gid_t *
crgetgroups(const cred_t *cr)
{
gid_t *gids;
int lock;
lock = (cr != current);
if (lock)
task_lock((struct task_struct *)cr);
get_group_info(cr->group_info);
gids = KGID_TO_SGID(cr->group_info->blocks[0]);
put_group_info(cr->group_info);
if (lock)
task_unlock((struct task_struct *)cr);
return gids;
}
/* Check if the passed gid is available is in supplied credential. */
int
groupmember(gid_t gid, const cred_t *cr)
{
int lock, rc;
lock = (cr != current);
if (lock)
task_lock((struct task_struct *)cr);
get_group_info(cr->group_info);
rc = cr_groups_search(cr->group_info, gid);
put_group_info(cr->group_info);
if (lock)
task_unlock((struct task_struct *)cr);
return rc;
}
#endif /* HAVE_CRED_STRUCT */
/* Return the effective user id */
uid_t
crgetuid(const cred_t *cr)
{
return KUID_TO_SUID(cr->euid);
}
/* Return the real user id */
uid_t
crgetruid(const cred_t *cr)
{
return KUID_TO_SUID(cr->uid);
}
/* Return the saved user id */
uid_t
crgetsuid(const cred_t *cr)
{
return KUID_TO_SUID(cr->suid);
}
/* Return the filesystem user id */
uid_t
crgetfsuid(const cred_t *cr)
{
return KUID_TO_SUID(cr->fsuid);
}
/* Return the effective group id */
gid_t
crgetgid(const cred_t *cr)
{
return KGID_TO_SGID(cr->egid);
}
/* Return the real group id */
gid_t
crgetrgid(const cred_t *cr)
{
return KGID_TO_SGID(cr->gid);
}
/* Return the saved group id */
gid_t
crgetsgid(const cred_t *cr)
{
return KGID_TO_SGID(cr->sgid);
}
/* Return the filesystem group id */
gid_t
crgetfsgid(const cred_t *cr)
{
return KGID_TO_SGID(cr->fsgid);
}
EXPORT_SYMBOL(crhold);
EXPORT_SYMBOL(crfree);
EXPORT_SYMBOL(crgetuid);
EXPORT_SYMBOL(crgetruid);
EXPORT_SYMBOL(crgetsuid);
EXPORT_SYMBOL(crgetfsuid);
EXPORT_SYMBOL(crgetgid);
EXPORT_SYMBOL(crgetrgid);
EXPORT_SYMBOL(crgetsgid);
EXPORT_SYMBOL(crgetfsgid);
EXPORT_SYMBOL(crgetngroups);
EXPORT_SYMBOL(crgetgroups);
EXPORT_SYMBOL(groupmember);