ksmbd: smbdirect: verify remaining_data_length respects max_fragmented_recv_size

This is inspired by the check for data_offset + data_length.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: stable@vger.kernel.org
Fixes: 2ea086e35c3d ("ksmbd: add buffer validation for smb direct")
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c
index d52f3757827631ae3c06daf51b7fdbc853cacc14..6550bd9f002c27d9503b3f9ee4199e64e4b5f415 100644 (file)
--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -554,7 +554,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
        case SMB_DIRECT_MSG_DATA_TRANSFER: {
                struct smb_direct_data_transfer *data_transfer =
                        (struct smb_direct_data_transfer *)recvmsg->packet;
-               unsigned int data_offset, data_length;
+               u32 remaining_data_length, data_offset, data_length;
                int avail_recvmsg_count, receive_credits;
 
                if (wc->byte_len <
@@ -564,6 +564,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
                        return;
                }
 
+               remaining_data_length = le32_to_cpu(data_transfer->remaining_data_length);
                data_length = le32_to_cpu(data_transfer->data_length);
                data_offset = le32_to_cpu(data_transfer->data_offset);
                if (wc->byte_len < data_offset ||
@@ -572,6 +573,14 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
                        smb_direct_disconnect_rdma_connection(t);
                        return;
                }
+               if (remaining_data_length > t->max_fragmented_recv_size ||
+                   data_length > t->max_fragmented_recv_size ||
+                   (u64)remaining_data_length + (u64)data_length >
+                   (u64)t->max_fragmented_recv_size) {
+                       put_recvmsg(t, recvmsg);
+                       smb_direct_disconnect_rdma_connection(t);
+                       return;
+               }
 
                if (data_length) {
                        if (t->full_packet_received)