[bug]: sweep: data race on TxPublisher.currentHeight

[morehouse]

TxPublisher.currentHeight is not guarded by a mutex but is accessed from multiple goroutines:

• in the monitor goroutine

  lnd/sweep/fee_bumper.go

  Line 718 in e8a1d48

  t.currentHeight = epoch.Height

• from outside calls to Broadcast

  lnd/sweep/fee_bumper.go

  Line 376 in e8a1d48

  confTarget := calcCurrentConfTarget(t.currentHeight, req.DeadlineHeight)

  lnd/sweep/fee_bumper.go

  Lines 544 to 545 in e8a1d48

  	log.Debugf("Publishing sweep tx %v, num_inputs=%v, height=%v",
  	txid, len(tx.TxIn), t.currentHeight)

  lnd/sweep/fee_bumper.go

  Lines 1124 to 1126 in e8a1d48

  	txFee, changeAmtOpt, locktimeOpt, err := prepareSweepTx(
  	inputs, changePkScript, feeRate, t.currentHeight,
  	)

  lnd/sweep/fee_bumper.go

  Line 1181 in e8a1d48

  sweepTx.LockTime = uint32(locktimeOpt.UnwrapOr(t.currentHeight))

• in the handleFeeBumpTx goroutine

  lnd/sweep/fee_bumper.go

  Lines 856 to 857 in e8a1d48

  	log.Errorf("Failed to increase fee rate for tx %v at "+
  	"height=%v: %v", oldTxid, t.currentHeight, err)

  lnd/sweep/fee_bumper.go

  Lines 864 to 865 in e8a1d48

  	log.Tracef("Skip bumping tx %v at height=%v", oldTxid,
  	t.currentHeight)

  lnd/sweep/fee_bumper.go

  Lines 1124 to 1126 in e8a1d48

  	txFee, changeAmtOpt, locktimeOpt, err := prepareSweepTx(
  	inputs, changePkScript, feeRate, t.currentHeight,
  	)

  lnd/sweep/fee_bumper.go

  Line 1181 in e8a1d48

  sweepTx.LockTime = uint32(locktimeOpt.UnwrapOr(t.currentHeight))

[Roasbeef]

Can prob throw in an https://pkg.go.dev/sync/atomic#Int32

[yyforyongyu]

Thanks for reporting! Also found this issue while fixing the itest flakes and have a local branch already - still needs more work, meanwhile will use atomic to provide a temp fix.