diff --git a/sys/kern/kern_acl.c b/sys/kern/kern_acl.c
index d2c878a5b930..2ae39e06932d 100644
--- a/sys/kern/kern_acl.c
+++ b/sys/kern/kern_acl.c
@@ -51,8 +51,8 @@ static int	vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type,
 	    struct acl *aclp);
 static int	vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type,
 	    struct acl *aclp);
-static int	vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
-	    struct acl *aclp);
+static int	vacl_aclcheck(struct proc *p, struct vnode *vp,
+	    acl_type_t type, struct acl *aclp);
 
 /*
  * Implement a version of vaccess() that understands POSIX.1e ACL semantics.
@@ -60,8 +60,8 @@ static int	vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
  * vaccess() eventually.
  */
 int
-vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
-    struct ucred *cred, int *privused)
+vaccess_acl_posix1e(enum vtype type, uid_t file_uid, gid_t file_gid,
+    struct acl *acl, mode_t acc_mode, struct ucred *cred, int *privused)
 {
 	struct acl_entry *acl_other, *acl_mask;
 	mode_t dac_granted;
@@ -123,7 +123,7 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 	for (i = 0; i < acl->acl_cnt; i++) {
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
-			if (acl->acl_entry[i].ae_id != cred->cr_uid)
+			if (file_uid != cred->cr_uid)
 				break;
 			dac_granted = 0;
 			dac_granted |= VADMIN;
@@ -209,13 +209,13 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 			dac_granted &= acl_mask_granted;
 			if ((acc_mode & dac_granted) == acc_mode)
 				return (0);
-			if ((acc_mode & (dac_granted | cap_granted)) ==
-			    acc_mode) {
-				if (privused != NULL)
-					*privused = 1;
-				return (0);
-			}
-			goto error;
+			if ((acc_mode & (dac_granted | cap_granted)) !=
+			    acc_mode)
+				goto error;
+
+			if (privused != NULL)
+				*privused = 1;
+			return (0);
 		}
 	}
 
@@ -229,22 +229,41 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 	for (i = 0; i < acl->acl_cnt; i++) {
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_GROUP_OBJ:
+			if (file_gid != cred->cr_groups[0])
+				break;
+			dac_granted = 0;
+			if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+			if (acl->acl_entry[i].ae_perm & ACL_READ)
+				dac_granted |= VREAD;
+			if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+				dac_granted |= VWRITE;
+			dac_granted  &= acl_mask_granted;
+
+			if ((acc_mode & dac_granted) == acc_mode)
+				return (0);
+
+			group_matched = 1;
+			break;
+
 		case ACL_GROUP:
-			if (groupmember(acl->acl_entry[i].ae_id, cred)) {
-				dac_granted = 0;
-				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
-					dac_granted |= VEXEC;
-				if (acl->acl_entry[i].ae_perm & ACL_READ)
-					dac_granted |= VREAD;
-				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
-					dac_granted |= VWRITE;
-				dac_granted  &= acl_mask_granted;
+			if (!groupmember(acl->acl_entry[i].ae_id, cred))
+				break;
+			dac_granted = 0;
+			if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+			if (acl->acl_entry[i].ae_perm & ACL_READ)
+				dac_granted |= VREAD;
+			if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+				dac_granted |= VWRITE;
+			dac_granted  &= acl_mask_granted;
 
-				if ((acc_mode & dac_granted) == acc_mode)
-					return (0);
+			if ((acc_mode & dac_granted) == acc_mode)
+				return (0);
+
+			group_matched = 1;
+			break;
 
-				group_matched = 1;
-			}
 		default:
 		}
 	}
@@ -257,27 +276,46 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 		for (i = 0; i < acl->acl_cnt; i++) {
 			switch (acl->acl_entry[i].ae_tag) {
 			case ACL_GROUP_OBJ:
-			case ACL_GROUP:
-				if (groupmember(acl->acl_entry[i].ae_id,
-				    cred)) {
-					dac_granted = 0;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_EXECUTE)
+				if (file_gid != cred->cr_groups[0])
+					break;
+				dac_granted = 0;
+				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
 					dac_granted |= VEXEC;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_READ)
-						dac_granted |= VREAD;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_WRITE)
-						dac_granted |= VWRITE;
-					dac_granted &= acl_mask_granted;
-					if ((acc_mode & (dac_granted |
-					    cap_granted)) == acc_mode) {
-						if (privused != NULL)
-							*privused = 1;
-						return (0);
-					}
-				}
+				if (acl->acl_entry[i].ae_perm & ACL_READ)
+					dac_granted |= VREAD;
+				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+					dac_granted |= VWRITE;
+				dac_granted &= acl_mask_granted;
+
+				if ((acc_mode & (dac_granted | cap_granted)) !=
+				    acc_mode)
+					break;
+
+				if (privused != NULL)
+					*privused = 1;
+				return (0);
+
+			case ACL_GROUP:
+				if (!groupmember(acl->acl_entry[i].ae_id,
+				    cred))
+					break;
+				dac_granted = 0;
+				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+				if (acl->acl_entry[i].ae_perm & ACL_READ)
+					dac_granted |= VREAD;
+				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+					dac_granted |= VWRITE;
+				dac_granted &= acl_mask_granted;
+
+				if ((acc_mode & (dac_granted | cap_granted)) !=
+				    acc_mode)
+					break;
+
+				if (privused != NULL)
+					*privused = 1;
+				return (0);
+
 			default:
 			}
 		}
@@ -454,21 +492,37 @@ acl_posix1e_check(struct acl *acl)
 		 */
 		switch(acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_user_obj++;
 			break;
 		case ACL_GROUP_OBJ:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_group_obj++;
 			break;
 		case ACL_USER:
+			if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_user++;
 			break;
 		case ACL_GROUP:
+			if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_group++;
 			break;
 		case ACL_OTHER:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_other++;
 			break;
 		case ACL_MASK:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_mask++;
 			break;
 		default:
diff --git a/sys/kern/subr_acl_posix1e.c b/sys/kern/subr_acl_posix1e.c
index d2c878a5b930..2ae39e06932d 100644
--- a/sys/kern/subr_acl_posix1e.c
+++ b/sys/kern/subr_acl_posix1e.c
@@ -51,8 +51,8 @@ static int	vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type,
 	    struct acl *aclp);
 static int	vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type,
 	    struct acl *aclp);
-static int	vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
-	    struct acl *aclp);
+static int	vacl_aclcheck(struct proc *p, struct vnode *vp,
+	    acl_type_t type, struct acl *aclp);
 
 /*
  * Implement a version of vaccess() that understands POSIX.1e ACL semantics.
@@ -60,8 +60,8 @@ static int	vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
  * vaccess() eventually.
  */
 int
-vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
-    struct ucred *cred, int *privused)
+vaccess_acl_posix1e(enum vtype type, uid_t file_uid, gid_t file_gid,
+    struct acl *acl, mode_t acc_mode, struct ucred *cred, int *privused)
 {
 	struct acl_entry *acl_other, *acl_mask;
 	mode_t dac_granted;
@@ -123,7 +123,7 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 	for (i = 0; i < acl->acl_cnt; i++) {
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
-			if (acl->acl_entry[i].ae_id != cred->cr_uid)
+			if (file_uid != cred->cr_uid)
 				break;
 			dac_granted = 0;
 			dac_granted |= VADMIN;
@@ -209,13 +209,13 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 			dac_granted &= acl_mask_granted;
 			if ((acc_mode & dac_granted) == acc_mode)
 				return (0);
-			if ((acc_mode & (dac_granted | cap_granted)) ==
-			    acc_mode) {
-				if (privused != NULL)
-					*privused = 1;
-				return (0);
-			}
-			goto error;
+			if ((acc_mode & (dac_granted | cap_granted)) !=
+			    acc_mode)
+				goto error;
+
+			if (privused != NULL)
+				*privused = 1;
+			return (0);
 		}
 	}
 
@@ -229,22 +229,41 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 	for (i = 0; i < acl->acl_cnt; i++) {
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_GROUP_OBJ:
+			if (file_gid != cred->cr_groups[0])
+				break;
+			dac_granted = 0;
+			if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+			if (acl->acl_entry[i].ae_perm & ACL_READ)
+				dac_granted |= VREAD;
+			if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+				dac_granted |= VWRITE;
+			dac_granted  &= acl_mask_granted;
+
+			if ((acc_mode & dac_granted) == acc_mode)
+				return (0);
+
+			group_matched = 1;
+			break;
+
 		case ACL_GROUP:
-			if (groupmember(acl->acl_entry[i].ae_id, cred)) {
-				dac_granted = 0;
-				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
-					dac_granted |= VEXEC;
-				if (acl->acl_entry[i].ae_perm & ACL_READ)
-					dac_granted |= VREAD;
-				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
-					dac_granted |= VWRITE;
-				dac_granted  &= acl_mask_granted;
+			if (!groupmember(acl->acl_entry[i].ae_id, cred))
+				break;
+			dac_granted = 0;
+			if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+			if (acl->acl_entry[i].ae_perm & ACL_READ)
+				dac_granted |= VREAD;
+			if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+				dac_granted |= VWRITE;
+			dac_granted  &= acl_mask_granted;
 
-				if ((acc_mode & dac_granted) == acc_mode)
-					return (0);
+			if ((acc_mode & dac_granted) == acc_mode)
+				return (0);
+
+			group_matched = 1;
+			break;
 
-				group_matched = 1;
-			}
 		default:
 		}
 	}
@@ -257,27 +276,46 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 		for (i = 0; i < acl->acl_cnt; i++) {
 			switch (acl->acl_entry[i].ae_tag) {
 			case ACL_GROUP_OBJ:
-			case ACL_GROUP:
-				if (groupmember(acl->acl_entry[i].ae_id,
-				    cred)) {
-					dac_granted = 0;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_EXECUTE)
+				if (file_gid != cred->cr_groups[0])
+					break;
+				dac_granted = 0;
+				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
 					dac_granted |= VEXEC;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_READ)
-						dac_granted |= VREAD;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_WRITE)
-						dac_granted |= VWRITE;
-					dac_granted &= acl_mask_granted;
-					if ((acc_mode & (dac_granted |
-					    cap_granted)) == acc_mode) {
-						if (privused != NULL)
-							*privused = 1;
-						return (0);
-					}
-				}
+				if (acl->acl_entry[i].ae_perm & ACL_READ)
+					dac_granted |= VREAD;
+				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+					dac_granted |= VWRITE;
+				dac_granted &= acl_mask_granted;
+
+				if ((acc_mode & (dac_granted | cap_granted)) !=
+				    acc_mode)
+					break;
+
+				if (privused != NULL)
+					*privused = 1;
+				return (0);
+
+			case ACL_GROUP:
+				if (!groupmember(acl->acl_entry[i].ae_id,
+				    cred))
+					break;
+				dac_granted = 0;
+				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+				if (acl->acl_entry[i].ae_perm & ACL_READ)
+					dac_granted |= VREAD;
+				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+					dac_granted |= VWRITE;
+				dac_granted &= acl_mask_granted;
+
+				if ((acc_mode & (dac_granted | cap_granted)) !=
+				    acc_mode)
+					break;
+
+				if (privused != NULL)
+					*privused = 1;
+				return (0);
+
 			default:
 			}
 		}
@@ -454,21 +492,37 @@ acl_posix1e_check(struct acl *acl)
 		 */
 		switch(acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_user_obj++;
 			break;
 		case ACL_GROUP_OBJ:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_group_obj++;
 			break;
 		case ACL_USER:
+			if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_user++;
 			break;
 		case ACL_GROUP:
+			if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_group++;
 			break;
 		case ACL_OTHER:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_other++;
 			break;
 		case ACL_MASK:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_mask++;
 			break;
 		default:
diff --git a/sys/kern/vfs_acl.c b/sys/kern/vfs_acl.c
index d2c878a5b930..2ae39e06932d 100644
--- a/sys/kern/vfs_acl.c
+++ b/sys/kern/vfs_acl.c
@@ -51,8 +51,8 @@ static int	vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type,
 	    struct acl *aclp);
 static int	vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type,
 	    struct acl *aclp);
-static int	vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
-	    struct acl *aclp);
+static int	vacl_aclcheck(struct proc *p, struct vnode *vp,
+	    acl_type_t type, struct acl *aclp);
 
 /*
  * Implement a version of vaccess() that understands POSIX.1e ACL semantics.
@@ -60,8 +60,8 @@ static int	vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
  * vaccess() eventually.
  */
 int
-vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
-    struct ucred *cred, int *privused)
+vaccess_acl_posix1e(enum vtype type, uid_t file_uid, gid_t file_gid,
+    struct acl *acl, mode_t acc_mode, struct ucred *cred, int *privused)
 {
 	struct acl_entry *acl_other, *acl_mask;
 	mode_t dac_granted;
@@ -123,7 +123,7 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 	for (i = 0; i < acl->acl_cnt; i++) {
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
-			if (acl->acl_entry[i].ae_id != cred->cr_uid)
+			if (file_uid != cred->cr_uid)
 				break;
 			dac_granted = 0;
 			dac_granted |= VADMIN;
@@ -209,13 +209,13 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 			dac_granted &= acl_mask_granted;
 			if ((acc_mode & dac_granted) == acc_mode)
 				return (0);
-			if ((acc_mode & (dac_granted | cap_granted)) ==
-			    acc_mode) {
-				if (privused != NULL)
-					*privused = 1;
-				return (0);
-			}
-			goto error;
+			if ((acc_mode & (dac_granted | cap_granted)) !=
+			    acc_mode)
+				goto error;
+
+			if (privused != NULL)
+				*privused = 1;
+			return (0);
 		}
 	}
 
@@ -229,22 +229,41 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 	for (i = 0; i < acl->acl_cnt; i++) {
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_GROUP_OBJ:
+			if (file_gid != cred->cr_groups[0])
+				break;
+			dac_granted = 0;
+			if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+			if (acl->acl_entry[i].ae_perm & ACL_READ)
+				dac_granted |= VREAD;
+			if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+				dac_granted |= VWRITE;
+			dac_granted  &= acl_mask_granted;
+
+			if ((acc_mode & dac_granted) == acc_mode)
+				return (0);
+
+			group_matched = 1;
+			break;
+
 		case ACL_GROUP:
-			if (groupmember(acl->acl_entry[i].ae_id, cred)) {
-				dac_granted = 0;
-				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
-					dac_granted |= VEXEC;
-				if (acl->acl_entry[i].ae_perm & ACL_READ)
-					dac_granted |= VREAD;
-				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
-					dac_granted |= VWRITE;
-				dac_granted  &= acl_mask_granted;
+			if (!groupmember(acl->acl_entry[i].ae_id, cred))
+				break;
+			dac_granted = 0;
+			if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+			if (acl->acl_entry[i].ae_perm & ACL_READ)
+				dac_granted |= VREAD;
+			if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+				dac_granted |= VWRITE;
+			dac_granted  &= acl_mask_granted;
 
-				if ((acc_mode & dac_granted) == acc_mode)
-					return (0);
+			if ((acc_mode & dac_granted) == acc_mode)
+				return (0);
+
+			group_matched = 1;
+			break;
 
-				group_matched = 1;
-			}
 		default:
 		}
 	}
@@ -257,27 +276,46 @@ vaccess_acl_posix1e(enum vtype type, struct acl *acl, mode_t acc_mode,
 		for (i = 0; i < acl->acl_cnt; i++) {
 			switch (acl->acl_entry[i].ae_tag) {
 			case ACL_GROUP_OBJ:
-			case ACL_GROUP:
-				if (groupmember(acl->acl_entry[i].ae_id,
-				    cred)) {
-					dac_granted = 0;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_EXECUTE)
+				if (file_gid != cred->cr_groups[0])
+					break;
+				dac_granted = 0;
+				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
 					dac_granted |= VEXEC;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_READ)
-						dac_granted |= VREAD;
-					if (acl->acl_entry[i].ae_perm &
-					    ACL_WRITE)
-						dac_granted |= VWRITE;
-					dac_granted &= acl_mask_granted;
-					if ((acc_mode & (dac_granted |
-					    cap_granted)) == acc_mode) {
-						if (privused != NULL)
-							*privused = 1;
-						return (0);
-					}
-				}
+				if (acl->acl_entry[i].ae_perm & ACL_READ)
+					dac_granted |= VREAD;
+				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+					dac_granted |= VWRITE;
+				dac_granted &= acl_mask_granted;
+
+				if ((acc_mode & (dac_granted | cap_granted)) !=
+				    acc_mode)
+					break;
+
+				if (privused != NULL)
+					*privused = 1;
+				return (0);
+
+			case ACL_GROUP:
+				if (!groupmember(acl->acl_entry[i].ae_id,
+				    cred))
+					break;
+				dac_granted = 0;
+				if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
+				dac_granted |= VEXEC;
+				if (acl->acl_entry[i].ae_perm & ACL_READ)
+					dac_granted |= VREAD;
+				if (acl->acl_entry[i].ae_perm & ACL_WRITE)
+					dac_granted |= VWRITE;
+				dac_granted &= acl_mask_granted;
+
+				if ((acc_mode & (dac_granted | cap_granted)) !=
+				    acc_mode)
+					break;
+
+				if (privused != NULL)
+					*privused = 1;
+				return (0);
+
 			default:
 			}
 		}
@@ -454,21 +492,37 @@ acl_posix1e_check(struct acl *acl)
 		 */
 		switch(acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_user_obj++;
 			break;
 		case ACL_GROUP_OBJ:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_group_obj++;
 			break;
 		case ACL_USER:
+			if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_user++;
 			break;
 		case ACL_GROUP:
+			if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_group++;
 			break;
 		case ACL_OTHER:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_other++;
 			break;
 		case ACL_MASK:
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
+			if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
+				return (EINVAL);
 			num_acl_mask++;
 			break;
 		default:
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index f8193485bc67..4f1ca3f4d872 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -563,8 +563,9 @@ int	speedup_syncer __P((void));
 int	textvp_fullpath __P((struct proc *p, char **retbuf, char **retfreebuf));
 int	vaccess __P((enum vtype type, mode_t file_mode, uid_t uid, gid_t gid,
 	    mode_t acc_mode, struct ucred *cred, int *privused));
-int	vaccess_acl_posix1e __P((enum vtype type, struct acl *acl,
-    mode_t acc_mode, struct ucred *cred, int *privused));
+int	vaccess_acl_posix1e __P((enum vtype type, uid_t file_uid,
+	    gid_t file_gid, struct acl *acl, mode_t acc_mode,
+	    struct ucred *cred, int *privused));
 void 	vattr_null __P((struct vattr *vap));
 int 	vcount __P((struct vnode *vp));
 void	vdrop __P((struct vnode *));
diff --git a/sys/ufs/ufs/ufs_acl.c b/sys/ufs/ufs/ufs_acl.c
index 042136c4affd..c78b0a473eea 100644
--- a/sys/ufs/ufs/ufs_acl.c
+++ b/sys/ufs/ufs/ufs_acl.c
@@ -79,23 +79,23 @@ ufs_sync_acl_from_inode(struct inode *ip, struct acl *acl)
 		case ACL_USER_OBJ:
 			acl->acl_entry[i].ae_perm = acl_posix1e_mode_to_perm(
 			    ACL_USER_OBJ, ip->i_mode);
-			acl->acl_entry[i].ae_id = ip->i_uid;
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID;
 			break;
 	
 		case ACL_GROUP_OBJ:
 			acl_group_obj = &acl->acl_entry[i];
-			acl->acl_entry[i].ae_id = ip->i_gid;
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID;
 			break;
 
 		case ACL_OTHER:
 			acl->acl_entry[i].ae_perm = acl_posix1e_mode_to_perm(
 			    ACL_OTHER, ip->i_mode);
-			acl->acl_entry[i].ae_id = 0;
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID;
 			break;
 
 		case ACL_MASK:
 			acl_mask = &acl->acl_entry[i];
-			acl->acl_entry[i].ae_id = 0;
+			acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID;
 			break;
 
 		case ACL_USER:
@@ -159,12 +159,10 @@ ufs_sync_inode_from_acl(struct acl *acl, struct inode *ip,
 		switch (acl->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
 			acl_user_obj = &acl->acl_entry[i];
-			ip->i_uid = acl->acl_entry[i].ae_id;
 			break;
 
 		case ACL_GROUP_OBJ:
 			acl_group_obj = &acl->acl_entry[i];
-			ip->i_gid = acl->acl_entry[i].ae_id;
 			break;
 
 		case ACL_OTHER:
@@ -191,14 +189,14 @@ ufs_sync_inode_from_acl(struct acl *acl, struct inode *ip,
 		/*
 		 * There is no ACL_MASK, so use the ACL_GROUP_OBJ entry.
 		 */
-		ip->i_mode &= ~ALLPERMS;
+		ip->i_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
 		ip->i_mode |= acl_posix1e_perms_to_mode(acl_user_obj,
 		    acl_group_obj, acl_other);
 	} else {
 		/*
 		 * Use the ACL_MASK entry.
 		 */
-		ip->i_mode &= ~ALLPERMS;
+		ip->i_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
 		ip->i_mode |= acl_posix1e_perms_to_mode(acl_user_obj,
 		    acl_mask, acl_other);
 	}
@@ -257,13 +255,13 @@ ufs_getacl(ap)
 			 */
 			ap->a_aclp->acl_cnt = 3;
 			ap->a_aclp->acl_entry[0].ae_tag = ACL_USER_OBJ;
-			ap->a_aclp->acl_entry[0].ae_id = 0;
+			ap->a_aclp->acl_entry[0].ae_id = ACL_UNDEFINED_ID;
 			ap->a_aclp->acl_entry[0].ae_perm = 0;
 			ap->a_aclp->acl_entry[1].ae_tag = ACL_GROUP_OBJ;
-			ap->a_aclp->acl_entry[1].ae_id = 0;
+			ap->a_aclp->acl_entry[1].ae_id = ACL_UNDEFINED_ID;
 			ap->a_aclp->acl_entry[1].ae_perm = 0;
 			ap->a_aclp->acl_entry[2].ae_tag = ACL_OTHER;
-			ap->a_aclp->acl_entry[2].ae_id = 0;
+			ap->a_aclp->acl_entry[2].ae_id = ACL_UNDEFINED_ID;
 			ap->a_aclp->acl_entry[2].ae_perm = 0;
 			ufs_sync_acl_from_inode(ip, ap->a_aclp);
 			error = 0;
@@ -359,11 +357,8 @@ ufs_setacl(ap)
 	} */ *ap;
 {
 	struct inode *ip = VTOI(ap->a_vp);
-	struct acl_entry *acl_user_obj, *acl_group_obj, *acl_other;
 	mode_t old_mode, preserve_mask;
-	uid_t old_uid, new_uid = 0;
-	gid_t old_gid, new_gid = 0;
-	int error, i;
+	int error;
 
 	/*
 	 * If this is a set operation rather than a delete operation,
@@ -405,64 +400,6 @@ ufs_setacl(ap)
 	if ((error = VOP_ACCESS(ap->a_vp, VADMIN, ap->a_cred, ap->a_p)))
 		return (error);
 
-	/*
-	 * ACL_TYPE_ACCESS may involve the changing of ownership, sticky
-	 * bit, setugid bits on the file or directory.  As such, it requires
-	 * special handling to identify these changes, and to authorize
-	 * them.
-	 * ACL_TYPE_DEFAULT does not require this, and ap->a_aclp should
-	 * not be dereferenced without a NULL check, as it may be a delete
-	 * operation.
-	 */
-	switch(ap->a_type) {
-	case ACL_TYPE_ACCESS:
-		/*
-		 * Identify ACL_USER_OBJ, ACL_GROUP_OBJ, and determine if
-		 * they have changed.  If so, authorize in the style of
-		 * ufs_chown().  While we're at it, identify ACL_OTHER.
-	 	 */
-		acl_user_obj = acl_group_obj = acl_other = NULL;
-		for (i = 0; i < ap->a_aclp->acl_cnt; i++)
-			switch(ap->a_aclp->acl_entry[i].ae_tag) {
-			case ACL_USER_OBJ:
-				acl_user_obj = &ap->a_aclp->acl_entry[i];
-				new_uid = acl_user_obj->ae_id;
-				break;
-			case ACL_GROUP_OBJ:
-				acl_group_obj = &ap->a_aclp->acl_entry[i];
-				new_gid = acl_group_obj->ae_id;
-				break;
-			case ACL_OTHER:
-				acl_other = &ap->a_aclp->acl_entry[i];
-				break;
-			default:
-			}
-		old_uid = ip->i_uid;
-		old_gid = ip->i_gid;
-
-		/*
-		 * Authorize changes to base object ownership in the style
-		 * of ufs_chown().
-		 */
-		if (new_uid != old_uid && (error = suser_xxx(ap->a_cred,
-		    ap->a_p, PRISON_ROOT)))
-			return (error);
-		if (new_gid != old_gid && !groupmember(new_gid, ap->a_cred) &&
-		    (error = suser_xxx(ap->a_cred, ap->a_p, PRISON_ROOT)))
-			return (error);
-
-	case ACL_TYPE_DEFAULT:
-		/*
-		 * ACL_TYPE_DEFAULT can literally be written straight into
-		 * the EA unhindered, as it has gone through sanity checking
-		 * already.
-	 	 */
-		break;
-
-	default:
-		panic("ufs_setacl(): unknown acl type\n");
-	}
-
 	switch(ap->a_type) {
 	case ACL_TYPE_ACCESS:
 		error = vn_extattr_set(ap->a_vp, IO_NODELOCKED,
@@ -509,22 +446,9 @@ ufs_setacl(ap)
 		 * Now that the EA is successfully updated, update the
 		 * inode and mark it as changed.
 		 */
-		old_uid = ip->i_uid;
-		old_gid = ip->i_gid;
 		old_mode = ip->i_mode;
 		preserve_mask = ISVTX | ISGID | ISUID;
 		ufs_sync_inode_from_acl(ap->a_aclp, ip, preserve_mask);
-
-		/*
-		 * Clear the ISGID and ISUID bits if the ownership has
-		 * changed, or appropriate privilege is not available.
-		 * XXX: This should probably be a check for broadening
-		 * availability of the bits, but it's not clear from the
-		 * spec.
-		 */
-		if (suser_xxx(ap->a_cred, NULL, PRISON_ROOT) &&
-		    (ip->i_gid != old_gid || ip->i_uid != old_uid))
-			ip->i_mode &= ~(ISUID | ISGID);
 		ip->i_flag |= IN_CHANGE;
 	}
 
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index 9db19e292a18..0b65496d88aa 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -353,8 +353,8 @@ ufs_access(ap)
 		    ap->a_mode, ap->a_cred, NULL);
 		break;
 	case 0:
-		error = vaccess_acl_posix1e(vp->v_type, acl, ap->a_mode,
-		    ap->a_cred, NULL);
+		error = vaccess_acl_posix1e(vp->v_type, ip->i_uid, ip->i_gid,
+		    acl, ap->a_mode, ap->a_cred, NULL);
 		break;
 	default:
 		printf("ufs_access(): Error retrieving ACL on object (%d).\n",