Fix channelmonitor fuzz test failure

diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs
index d212a3fdbe43b960ffd2a0fe4e46fd366522aae3..8c3fcc3f0a02ad21dbb838759241e57eec4e70b7 100644 (file)
--- a/src/ln/channelmonitor.rs
+++ b/src/ln/channelmonitor.rs
@@ -770,7 +770,14 @@ impl ChannelMonitor {
                        () => {
                                {
                                        let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
-                                       let tx: Transaction = unwrap_obj!(serialize::deserialize(read_bytes!(tx_len)));
+                                       let tx_ser = read_bytes!(tx_len);
+                                       let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
+                                       if serialize::serialize(&tx).unwrap() != tx_ser {
+                                               // We check that the tx re-serializes to the same form to ensure there is
+                                               // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
+                                               // all that well.
+                                               return None;
+                                       }
 
                                        let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
                                        let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));