Index: sys/kern/vfs_vnops.c
===================================================================
--- sys/kern/vfs_vnops.c
+++ sys/kern/vfs_vnops.c
@@ -3465,6 +3465,7 @@
 vn_deallocate_impl(struct vnode *vp, off_t *offset, off_t *length, int flags,
     int ioflag, struct ucred *active_cred, struct ucred *file_cred)
 {
+	struct ucred *cred;
 	struct mount *mp;
 	void *rl_cookie;
 	off_t off, len;
@@ -3508,9 +3509,14 @@
 			error = mac_vnode_check_write(active_cred, file_cred,
 			    vp);
 #endif
-		if (error == 0)
+		if (error == 0) {
+			if (file_cred != NULL)
+				cred = file_cred;
+			else
+				cred = active_cred;
 			error = VOP_DEALLOCATE(vp, &off, &len, flags, ioflag,
-			    active_cred);
+			    cred);
+		}
 
 		if ((ioflag & IO_NODELOCKED) == 0) {
 			VOP_UNLOCK(vp);