libceph: make sure redirect does not change namespace

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/osd_client.c

@@ -2608,10 +2608,23 @@ static int ceph_oloc_decode(void **p, void *end,
 	}
 
 	if (struct_v >= 5) {
+		bool changed = false;
+
 		len = ceph_decode_32(p);
 		if (len > 0) {
 			ceph_decode_need(p, end, len, e_inval);
+			if (!oloc->pool_ns ||
+			    ceph_compare_string(oloc->pool_ns, *p, len))
+				changed = true;
 			*p += len;
+		} else {
+			if (oloc->pool_ns)
+				changed = true;
+		}
+		if (changed) {
+			/* redirect changes namespace */
+			pr_warn("ceph_object_locator::nspace is changed\n");
+			goto e_inval;
 		}
 	}
 
@@ -2820,7 +2833,9 @@ static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
 		goto out_unlock_session;
 	}
 
+	m.redirect.oloc.pool_ns = req->r_t.target_oloc.pool_ns;
 	ret = decode_MOSDOpReply(msg, &m);
+	m.redirect.oloc.pool_ns = NULL;
 	if (ret) {
 		pr_err("failed to decode MOSDOpReply for tid %llu: %d\n",
 		       req->r_tid, ret);