Outgoing transfer counting change as incoming payment

[mrtestyboy781]

Issue

On two rare occasions (less than .01% of all payments) we have seen the wallet create a transfer where the change is counted as an incoming payment and is visible in get_bulk_payments, get_transfers, and get_transfer_by_txid as type="in"

The change itself is using a payment id we haven't issued before, so it looks like an erroneous deposit to our wallet, when instead it's just change, and would normally not show up as an incoming payment.

The payment itself constructed in a view-only / offline setup, where transfer is used to create the unsigned tx, its send to offline wallet to sign_transfer and broadcast later with submit_transfer

Monerod Version : v0.17.1.9

Details

Expected output

In a normal outgoing transfer, you would see get_transfer_by_txid return

{
  "id": "0",
  "jsonrpc": "2.0",
  "result": {
    "transfer": {
      "address": "OUTGOING_ADDRESS",
      "amount": 1171780000000,
      "confirmations": 11,
      "destinations": [{
        "address": "OUTGOING_ADDRESS",
        "amount": 1171780000000
      }],
      "double_spend_seen": false,
      "fee": 6930000,
      "height": 2550596,
      "locked": false,
      "note": "",
      "payment_id": "XXXXXXXXXXX",
      "subaddr_index": {
        "major": 0,
        "minor": 0
      },
      "subaddr_indices": [{
        "major": 0,
        "minor": 0
      }],
      "suggested_confirmations_threshold": 2,
      "timestamp": 1643794568,
      "txid": "XXXXXXXXXXXX",
      "type": "out",
      "unlock_time": 0
    },
    "transfers": [{
      "address": "OUTGOING_ADDRESS",
      "amount": 1171780000000,
      "confirmations": 11,
      "destinations": [{
        "address": "OUTGOING_ADDRESS",
        "amount": 1171780000000
      }],
      "double_spend_seen": false,
      "fee": 6930000,
      "height": 2550596,
      "locked": false,
      "note": "",
      "payment_id": "XXXXXX",
      "subaddr_index": {
        "major": 0,
        "minor": 0
      },
      "subaddr_indices": [{
        "major": 0,
        "minor": 0
      }],
      "suggested_confirmations_threshold": 2,
      "timestamp": 1643794568,
      "txid": "XXXXXXX",
      "type": "out",
      "unlock_time": 0
    }]
  }
}

Note type=out, and get_bulk_payments would return nothing matching the txid, since change is ignored.

Actual output

Now, for these transfers where change is counted as an incoming payment we see

{
  "id": "0",
  "jsonrpc": "2.0",
  "result": {
    "transfer": {
      "address": "MAIN_ADDRESS",
      "amount": 42448162320000,
      "amounts": [42448162320000],
      "confirmations": 53354,
      "double_spend_seen": false,
      "fee": 7680000,
      "height": 2497242,
      "locked": false,
      "note": "",
      "payment_id": "YYYYYYYYYYYY",
      "subaddr_index": {
        "major": 0,
        "minor": 0
      },
      "subaddr_indices": [{
        "major": 0,
        "minor": 0
      }],
      "suggested_confirmations_threshold": 60,
      "timestamp": 1637390686,
      "txid": "XXXXXXXXXXXXXX",
      "type": "in",
      "unlock_time": 0
    },
    "transfers": [{
      "address": "MAIN_ADDRESS",
      "amount": 42448162320000,
      "amounts": [42448162320000],
      "confirmations": 53354,
      "double_spend_seen": false,
      "fee": 7680000,
      "height": 2497242,
      "locked": false,
      "note": "",
      "payment_id": "YYYYYYYYYYYY",
      "subaddr_index": {
        "major": 0,
        "minor": 0
      },
      "subaddr_indices": [{
        "major": 0,
        "minor": 0
      }],
      "suggested_confirmations_threshold": 60,
      "timestamp": 1637390686,
      "txid": "XXXXXXXXXXXXXX",
      "type": "in",
      "unlock_time": 0
    },{
      "address": "OUTGOING_ADDRESS",
      "amount": 2551830000000,
      "confirmations": 53354,
      "destinations": [{
        "address": "OUTGOING_ADDRESS,
        "amount": 2551830000000
      }],
      "double_spend_seen": false,
      "fee": 7680000,
      "height": 2497242,
      "locked": false,
      "note": "",
      "payment_id": "XXXXXXXXXXXXXX",
      "subaddr_index": {
        "major": 0,
        "minor": 0
      },
      "subaddr_indices": [{
        "major": 0,
        "minor": 61807
      }],
      "suggested_confirmations_threshold": 4,
      "timestamp": 1637390678,
      "txid": "XXXXXXXXXXXXXX",
      "type": "out",
      "unlock_time": 0
    }]
  }
}

Note type=in and in get_bulk_payments we see an incoming transfer of 42448162320000 listed

[moneromooo-monero]

Is is possible that you might have imported key images while the hot wallet was connected to an untrusted daemon (that is, a daemon that was not on 127.0.0.1 and where --trusted-daemon was not specified, OR any daemon with --untrusted-daemon specified) ? If that it the case, then I understand why this would happen (first step to fixing it).

[moneromooo-monero]

After looking some more, this only applies to hardware wallets, so this doens't appear to be your case.

[mrtestyboy781]

It is possibly related to key image import, its something we have done in the past to re-sync watchonly wallet with offline signer

[j-berman]

@mrtestyboy781 are these transfers with the issue self-spends back to your own subaddress by chance?

[mrtestyboy781]

In this case they were not self-spends, it was...

main wallet -> 2 outputs 1 external output 1 change output

but it seems like your fix may solve the issue?

[j-berman]

I don't believe that fix would solve this issue unfortunately then. Sounds like this may be something else