Fix ACL checks for NFS kernel server

This PR changes ZFS ACL checks to evaluate
fsuid / fsgid rather than euid / egid to avoid
accidentally granting elevated permissions to
NFS clients.

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Andrew Walker <awalker@ixsystems.com>
Co-authored-by: Ryan Moeller <freqlabs@FreeBSD.org>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #13221
This commit is contained in:
Brian Behlendorf 2022-03-20 21:21:18 -07:00 committed by GitHub
parent 9e3619c535
commit 847d03060f
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
12 changed files with 27 additions and 270 deletions

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@ -22,7 +22,6 @@ KERNEL_H = \
inttypes.h \
isa_defs.h \
kmem_cache.h \
kidmap.h \
kmem.h \
kstat.h \
list_impl.h \

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@ -48,138 +48,20 @@ extern "C" {
typedef struct ucred cred_t;
#define CRED() curthread->td_ucred
/*
* kcred is used when you need all privileges.
*/
#define kcred (thread0.td_ucred)
#define KUID_TO_SUID(x) (x)
#define KGID_TO_SGID(x) (x)
#define crgetuid(cred) ((cred)->cr_uid)
#define crgetruid(cred) ((cred)->cr_ruid)
#define crgetgid(cred) ((cred)->cr_gid)
#define crgetgroups(cred) ((cred)->cr_groups)
#define crgetngroups(cred) ((cred)->cr_ngroups)
#define crgetsid(cred, i) (NULL)
struct proc; /* cred.h is included in proc.h */
struct prcred;
struct ksid;
struct ksidlist;
struct credklpd;
struct credgrp;
struct auditinfo_addr; /* cred.h is included in audit.h */
extern int ngroups_max;
/*
* kcred is used when you need all privileges.
*/
extern void cred_init(void);
extern void crfree(cred_t *);
extern cred_t *cralloc(void); /* all but ref uninitialized */
extern cred_t *cralloc_ksid(void); /* cralloc() + ksid alloc'ed */
extern cred_t *crget(void); /* initialized */
extern void crcopy_to(cred_t *, cred_t *);
extern cred_t *crdup(cred_t *);
extern void crdup_to(cred_t *, cred_t *);
extern cred_t *crgetcred(void);
extern void crset(struct proc *, cred_t *);
extern void crset_zone_privall(cred_t *);
extern int supgroupmember(gid_t, const cred_t *);
extern int hasprocperm(const cred_t *, const cred_t *);
extern int prochasprocperm(struct proc *, struct proc *, const cred_t *);
extern int crcmp(const cred_t *, const cred_t *);
extern cred_t *zone_kcred(void);
extern gid_t crgetrgid(const cred_t *);
extern gid_t crgetsgid(const cred_t *);
#define crgetuid(cr) ((cr)->cr_uid)
#define crgetruid(cr) ((cr)->cr_ruid)
#define crgetgid(cr) ((cr)->cr_gid)
#define crgetgroups(cr) ((cr)->cr_groups)
#define crgetngroups(cr) ((cr)->cr_ngroups)
#define crgetzoneid(cr) ((cr)->cr_prison->pr_id)
extern projid_t crgetprojid(const cred_t *);
extern cred_t *crgetmapped(const cred_t *);
extern const struct auditinfo_addr *crgetauinfo(const cred_t *);
extern struct auditinfo_addr *crgetauinfo_modifiable(cred_t *);
extern uint_t crgetref(const cred_t *);
extern const gid_t *crgetggroups(const struct credgrp *);
/*
* Sets real, effective and/or saved uid/gid;
* -1 argument accepted as "no change".
*/
extern int crsetresuid(cred_t *, uid_t, uid_t, uid_t);
extern int crsetresgid(cred_t *, gid_t, gid_t, gid_t);
/*
* Sets real, effective and saved uids/gids all to the same
* values. Both values must be non-negative and <= MAXUID
*/
extern int crsetugid(cred_t *, uid_t, gid_t);
/*
* Functions to handle the supplemental group list.
*/
extern struct credgrp *crgrpcopyin(int, gid_t *);
extern void crgrprele(struct credgrp *);
extern void crsetcredgrp(cred_t *, struct credgrp *);
/*
* Private interface for setting zone association of credential.
*/
struct zone;
extern void crsetzone(cred_t *, struct zone *);
extern struct zone *crgetzone(const cred_t *);
/*
* Private interface for setting project id in credential.
*/
extern void crsetprojid(cred_t *, projid_t);
/*
* Private interface for nfs.
*/
extern cred_t *crnetadjust(cred_t *);
/*
* Private interface for procfs.
*/
extern void cred2prcred(const cred_t *, struct prcred *);
/*
* Private interfaces for Rampart Trusted Solaris.
*/
struct ts_label_s;
extern struct ts_label_s *crgetlabel(const cred_t *);
extern boolean_t crisremote(const cred_t *);
/*
* Private interfaces for ephemeral uids.
*/
#define VALID_UID(id, zn) \
((id) <= MAXUID || valid_ephemeral_uid((zn), (id)))
#define VALID_GID(id, zn) \
((id) <= MAXUID || valid_ephemeral_gid((zn), (id)))
extern boolean_t valid_ephemeral_uid(struct zone *, uid_t);
extern boolean_t valid_ephemeral_gid(struct zone *, gid_t);
extern int eph_uid_alloc(struct zone *, int, uid_t *, int);
extern int eph_gid_alloc(struct zone *, int, gid_t *, int);
extern void crsetsid(cred_t *, struct ksid *, int);
extern void crsetsidlist(cred_t *, struct ksidlist *);
extern struct ksidlist *crgetsidlist(const cred_t *);
extern int crsetpriv(cred_t *, ...);
extern struct credklpd *crgetcrklpd(const cred_t *);
extern void crsetcrklpd(cred_t *, struct credklpd *);
#ifdef __cplusplus
}

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@ -1,41 +0,0 @@
/*
* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _OPENSOLARIS_SYS_KIDMAP_H_
#define _OPENSOLARIS_SYS_KIDMAP_H_
#include <sys/idmap.h>
typedef int32_t idmap_stat;
typedef void idmap_get_handle_t;
#define kidmap_get_create() (NULL)
#define kidmap_get_destroy(hdl) do { } while (0)
#define kidmap_get_mappings(hdl) (NULL)
#endif /* _OPENSOLARIS_SYS_KIDMAP_H_ */

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@ -29,7 +29,6 @@
#ifndef _OPENSOLARIS_SYS_SID_H_
#define _OPENSOLARIS_SYS_SID_H_
#include <sys/idmap.h>
#include <sys/kidmap.h>
typedef struct ksiddomain {
char *kd_name; /* Domain part of SID */
@ -59,28 +58,4 @@ ksiddomain_rele(ksiddomain_t *kd)
kmem_free(kd, sizeof (*kd));
}
static __inline uint_t
ksid_getid(ksid_t *ks)
{
panic("%s has been unexpectedly called", __func__);
}
static __inline const char *
ksid_getdomain(ksid_t *ks)
{
panic("%s has been unexpectedly called", __func__);
}
static __inline uint_t
ksid_getrid(ksid_t *ks)
{
panic("%s has been unexpectedly called", __func__);
}
#define kidmap_getsidbyuid(zone, uid, sid_prefix, rid) (1)
#define kidmap_getsidbygid(zone, gid, sid_prefix, rid) (1)
#endif /* _OPENSOLARIS_SYS_SID_H_ */

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@ -49,12 +49,7 @@ extern void crhold(cred_t *cr);
extern void crfree(cred_t *cr);
extern uid_t crgetuid(const cred_t *cr);
extern uid_t crgetruid(const cred_t *cr);
extern uid_t crgetsuid(const cred_t *cr);
extern uid_t crgetfsuid(const cred_t *cr);
extern gid_t crgetgid(const cred_t *cr);
extern gid_t crgetrgid(const cred_t *cr);
extern gid_t crgetsgid(const cred_t *cr);
extern gid_t crgetfsgid(const cred_t *cr);
extern int crgetngroups(const cred_t *cr);
extern gid_t *crgetgroups(const cred_t *cr);
extern int groupmember(gid_t gid, const cred_t *cr);

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@ -32,7 +32,7 @@ CFLAGS+= -include ${INCDIR}/os/freebsd/spl/sys/ccompile.h
CFLAGS+= -D__KERNEL__ -DFREEBSD_NAMECACHE -DBUILDING_ZFS -D__BSD_VISIBLE=1 \
-DHAVE_UIO_ZEROCOPY -DWITHOUT_NETDUMP -D__KERNEL -D_SYS_CONDVAR_H_ \
-D_SYS_VMEM_H_ -DKDTRACE_HOOKS -DSMP -DHAVE_KSID -DCOMPAT_FREEBSD11
-D_SYS_VMEM_H_ -DKDTRACE_HOOKS -DSMP -DCOMPAT_FREEBSD11
.if ${MACHINE_ARCH} == "amd64"
CFLAGS+= -DHAVE_AVX2 -DHAVE_AVX -D__x86_64 -DHAVE_SSE2 -DHAVE_AVX512F -DHAVE_SSSE3

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@ -1653,8 +1653,10 @@ zfs_acl_ids_create(znode_t *dzp, int flag, vattr_t *vap, cred_t *cr,
ZFS_GROUP, &acl_ids->z_fuidp);
gid = vap->va_gid;
} else {
acl_ids->z_fuid = zfs_fuid_create_cred(zfsvfs, ZFS_OWNER,
cr, &acl_ids->z_fuidp);
uid_t id = crgetuid(cr);
if (IS_EPHEMERAL(id))
id = UID_NOBODY;
acl_ids->z_fuid = (uint64_t)id;
acl_ids->z_fgid = 0;
if (vap->va_mask & AT_GID) {
acl_ids->z_fgid = zfs_fuid_create(zfsvfs,

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@ -1060,8 +1060,7 @@ zfs_create(znode_t *dzp, const char *name, vattr_t *vap, int excl, int mode,
objset_t *os;
dmu_tx_t *tx;
int error;
ksid_t *ksid;
uid_t uid;
uid_t uid = crgetuid(cr);
gid_t gid = crgetgid(cr);
uint64_t projid = ZFS_DEFAULT_PROJID;
zfs_acl_ids_t acl_ids;
@ -1075,13 +1074,6 @@ zfs_create(znode_t *dzp, const char *name, vattr_t *vap, int excl, int mode,
* If we have an ephemeral id, ACL, or XVATTR then
* make sure file system is at proper version
*/
ksid = crgetsid(cr, KSID_OWNER);
if (ksid)
uid = ksid_getid(ksid);
else
uid = crgetuid(cr);
if (zfsvfs->z_use_fuids == B_FALSE &&
(vsecp || (vap->va_mask & AT_XVATTR) ||
IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
@ -1415,8 +1407,7 @@ zfs_mkdir(znode_t *dzp, const char *dirname, vattr_t *vap, znode_t **zpp,
uint64_t txtype;
dmu_tx_t *tx;
int error;
ksid_t *ksid;
uid_t uid;
uid_t uid = crgetuid(cr);
gid_t gid = crgetgid(cr);
zfs_acl_ids_t acl_ids;
boolean_t fuid_dirtied;
@ -1427,12 +1418,6 @@ zfs_mkdir(znode_t *dzp, const char *dirname, vattr_t *vap, znode_t **zpp,
* If we have an ephemeral id, ACL, or XVATTR then
* make sure file system is at proper version
*/
ksid = crgetsid(cr, KSID_OWNER);
if (ksid)
uid = ksid_getid(ksid);
else
uid = crgetuid(cr);
if (zfsvfs->z_use_fuids == B_FALSE &&
((vap->va_mask & AT_XVATTR) ||
IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))

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@ -128,7 +128,7 @@ groupmember(gid_t gid, const cred_t *cr)
uid_t
crgetuid(const cred_t *cr)
{
return (KUID_TO_SUID(cr->euid));
return (KUID_TO_SUID(cr->fsuid));
}
/* Return the real user id */
@ -138,44 +138,9 @@ 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));
}
@ -184,12 +149,7 @@ 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);

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@ -121,7 +121,7 @@ secpolicy_vnode_access2(const cred_t *cr, struct inode *ip, uid_t owner,
int
secpolicy_vnode_any_access(const cred_t *cr, struct inode *ip, uid_t owner)
{
if (crgetfsuid(cr) == owner)
if (crgetuid(cr) == owner)
return (0);
if (zpl_inode_owner_or_capable(kcred->user_ns, ip))
@ -147,7 +147,7 @@ secpolicy_vnode_any_access(const cred_t *cr, struct inode *ip, uid_t owner)
int
secpolicy_vnode_chown(const cred_t *cr, uid_t owner)
{
if (crgetfsuid(cr) == owner)
if (crgetuid(cr) == owner)
return (0);
#if defined(CONFIG_USER_NS)
@ -184,7 +184,7 @@ secpolicy_vnode_remove(const cred_t *cr)
int
secpolicy_vnode_setdac(const cred_t *cr, uid_t owner)
{
if (crgetfsuid(cr) == owner)
if (crgetuid(cr) == owner)
return (0);
#if defined(CONFIG_USER_NS)
@ -220,7 +220,7 @@ secpolicy_vnode_setids_setgids(const cred_t *cr, gid_t gid)
if (!kgid_has_mapping(cr->user_ns, SGID_TO_KGID(gid)))
return (EPERM);
#endif
if (crgetfsgid(cr) != gid && !groupmember(gid, cr))
if (crgetgid(cr) != gid && !groupmember(gid, cr))
return (priv_policy_user(cr, CAP_FSETID, EPERM));
return (0);
@ -286,7 +286,7 @@ secpolicy_setid_clear(vattr_t *vap, cred_t *cr)
static int
secpolicy_vnode_setid_modify(const cred_t *cr, uid_t owner)
{
if (crgetfsuid(cr) == owner)
if (crgetuid(cr) == owner)
return (0);
#if defined(CONFIG_USER_NS)

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@ -116,14 +116,14 @@ zpl_vap_init(vattr_t *vap, struct inode *dir, umode_t mode, cred_t *cr)
{
vap->va_mask = ATTR_MODE;
vap->va_mode = mode;
vap->va_uid = crgetfsuid(cr);
vap->va_uid = crgetuid(cr);
if (dir && dir->i_mode & S_ISGID) {
vap->va_gid = KGID_TO_SGID(dir->i_gid);
if (S_ISDIR(mode))
vap->va_mode |= S_ISGID;
} else {
vap->va_gid = crgetfsgid(cr);
vap->va_gid = crgetgid(cr);
}
}

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@ -492,8 +492,8 @@ zpl_xattr_set_dir(struct inode *ip, const char *name, const void *value,
vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP);
vap->va_mode = xattr_mode;
vap->va_mask = ATTR_MODE;
vap->va_uid = crgetfsuid(cr);
vap->va_gid = crgetfsgid(cr);
vap->va_uid = crgetuid(cr);
vap->va_gid = crgetgid(cr);
error = -zfs_create(dxzp, (char *)name, vap, 0, 0644, &xzp,
cr, 0, NULL);