ceph: don't drop message if it contains more data than expected

Later version mds may encode more data into messages.
Signed-off-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

fs/ceph/mds_client.c

@@ -3406,10 +3406,10 @@ static void handle_lease(struct ceph_mds_client *mdsc,
 	vino.ino = le64_to_cpu(h->ino);
 	vino.snap = CEPH_NOSNAP;
 	seq = le32_to_cpu(h->seq);
-	dname.name = (void *)h + sizeof(*h) + sizeof(u32);
-	dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
-	if (dname.len != get_unaligned_le32(h+1))
+	dname.len = get_unaligned_le32(h + 1);
+	if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
 		goto bad;
+	dname.name = (void *)(h + 1) + sizeof(u32);
 
 	/* lookup inode */
 	inode = ceph_find_inode(sb, vino);

fs/ceph/quota.c

@@ -48,7 +48,7 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
 	struct inode *inode;
 	struct ceph_inode_info *ci;
 
-	if (msg->front.iov_len != sizeof(*h)) {
+	if (msg->front.iov_len < sizeof(*h)) {
 		pr_err("%s corrupt message mds%d len %d\n", __func__,
 		       session->s_mds, (int)msg->front.iov_len);
 		ceph_msg_dump(msg);