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>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #13221
This commit is contained in:
Ryan Moeller
2022-03-18 08:47:57 -04:00
committed by GitHub
parent a5920d24c0
commit d42979c6ef
12 changed files with 27 additions and 270 deletions
+1 -1
View File
@@ -35,7 +35,7 @@ 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
+4 -2
View File
@@ -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,
+2 -17
View File
@@ -1043,8 +1043,7 @@ 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;
@@ -1058,13 +1057,6 @@ 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)))
@@ -1396,8 +1388,7 @@ 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;
@@ -1408,12 +1399,6 @@ 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)))
+1 -41
View File
@@ -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);
+5 -5
View File
@@ -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)
+2 -2
View File
@@ -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);
}
}
+2 -2
View File
@@ -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);