diff --git a/[refs] b/[refs]
index c0322999e787..39449a303f73 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6e14b1a6c3b8d7e48ece68733d2dac0464611ee4
+refs/heads/master: 3e8f43a089f06279c5f76a9ccd42578eebf7bfa5
diff --git a/trunk/fs/ceph/mds_client.c b/trunk/fs/ceph/mds_client.c
index a5a735422aa7..1bcf712655d9 100644
--- a/trunk/fs/ceph/mds_client.c
+++ b/trunk/fs/ceph/mds_client.c
@@ -2625,7 +2625,8 @@ static void check_new_map(struct ceph_mds_client *mdsc,
 		     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
 		     session_state_name(s->s_state));
 
-		if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
+		if (i >= newmap->m_max_mds ||
+		    memcmp(ceph_mdsmap_get_addr(oldmap, i),
 			   ceph_mdsmap_get_addr(newmap, i),
 			   sizeof(struct ceph_entity_addr))) {
 			if (s->s_state == CEPH_MDS_SESSION_OPENING) {