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 <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Co-authored-by: Andrew Walker <[email protected]>
Co-authored-by: Ryan Moeller <[email protected]>
Signed-off-by: Ryan Moeller <[email protected]>
Closes #13221

12 files changed, 26 insertions, 269 deletions

diff --git a/include/os/freebsd/spl/sys/Makefile.am b/include/os/freebsd/spl/sys/Makefile.am
index 232aaf569..7488e56c7 100644
--- a/include/os/freebsd/spl/sys/Makefile.am
+++ b/include/os/freebsd/spl/sys/Makefile.am
@@ -22,7 +22,6 @@ KERNEL_H = \
 	inttypes.h \
 	isa_defs.h \
 	kmem_cache.h \
-	kidmap.h \
 	kmem.h \
 	kstat.h \
 	list_impl.h \
diff --git a/include/os/freebsd/spl/sys/cred.h b/include/os/freebsd/spl/sys/cred.h
index 86f79011d..db986af57 100644
--- a/include/os/freebsd/spl/sys/cred.h
+++ b/include/os/freebsd/spl/sys/cred.h
@@ -48,138 +48,20 @@ extern "C" {
 typedef struct ucred cred_t;
 
 #define	CRED()		curthread->td_ucred
-#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.
  */
+#define	kcred	(thread0.td_ucred)
 
-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	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 *);
+#define	KUID_TO_SUID(x)		(x)
+#define	KGID_TO_SGID(x)		(x)
+#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)
 
 #ifdef	__cplusplus
 }
diff --git a/include/os/freebsd/spl/sys/kidmap.h b/include/os/freebsd/spl/sys/kidmap.h
deleted file mode 100644
index dc0cf5988..000000000
--- a/include/os/freebsd/spl/sys/kidmap.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright (c) 2007 Pawel Jakub Dawidek <[email protected]>
- * 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_ */
diff --git a/include/os/freebsd/spl/sys/sid.h b/include/os/freebsd/spl/sys/sid.h
index d3fab8b24..f249d05d5 100644
--- a/include/os/freebsd/spl/sys/sid.h
+++ b/include/os/freebsd/spl/sys/sid.h
@@ -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_ */
diff --git a/include/os/linux/spl/sys/cred.h b/include/os/linux/spl/sys/cred.h
index 9cc85deb5..b7d3f38d7 100644
--- a/include/os/linux/spl/sys/cred.h
+++ b/include/os/linux/spl/sys/cred.h
@@ -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);
diff --git a/module/Makefile.bsd b/module/Makefile.bsd
index 8aa4ed222..dc6cc2b74 100644
--- a/module/Makefile.bsd
+++ b/module/Makefile.bsd
@@ -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
diff --git a/module/os/freebsd/zfs/zfs_acl.c b/module/os/freebsd/zfs/zfs_acl.c
index ae758bcef..fe0f69132 100644
--- a/module/os/freebsd/zfs/zfs_acl.c
+++ b/module/os/freebsd/zfs/zfs_acl.c
@@ -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,
diff --git a/module/os/freebsd/zfs/zfs_vnops_os.c b/module/os/freebsd/zfs/zfs_vnops_os.c
index 7bcf80bf5..b2cc3d063 100644
--- a/module/os/freebsd/zfs/zfs_vnops_os.c
+++ b/module/os/freebsd/zfs/zfs_vnops_os.c
@@ -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)))
diff --git a/module/os/linux/spl/spl-cred.c b/module/os/linux/spl/spl-cred.c
index 8fe1cc30b..f81b9540a 100644
--- a/module/os/linux/spl/spl-cred.c
+++ b/module/os/linux/spl/spl-cred.c
@@ -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 */
@@ -138,45 +138,10 @@ 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);
diff --git a/module/os/linux/zfs/policy.c b/module/os/linux/zfs/policy.c
index bbccb2e57..5a52092bb 100644
--- a/module/os/linux/zfs/policy.c
+++ b/module/os/linux/zfs/policy.c
@@ -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)
diff --git a/module/os/linux/zfs/zpl_inode.c b/module/os/linux/zfs/zpl_inode.c
index 24a8b036b..4f79265a0 100644
--- a/module/os/linux/zfs/zpl_inode.c
+++ b/module/os/linux/zfs/zpl_inode.c
@@ -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);
 	}
 }
 
diff --git a/module/os/linux/zfs/zpl_xattr.c b/module/os/linux/zfs/zpl_xattr.c
index 928058ef6..e088db5d2 100644
--- a/module/os/linux/zfs/zpl_xattr.c
+++ b/module/os/linux/zfs/zpl_xattr.c
@@ -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);