rpcserver: add time_lock_delta overflow check

cmd/lncli/commands.go

@@ -21,6 +21,7 @@ import (
 	"github.com/lightninglabs/protobuf-hex-display/jsonpb"
 	"github.com/lightninglabs/protobuf-hex-display/proto"
 	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/routing"
 	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/lightningnetwork/lnd/signal"
 	"github.com/urfave/cli"
@@ -2029,7 +2030,7 @@ var updateChannelPolicyCommand = cli.Command{
 				"with a granularity of 0.000001 (millionths). Can not " +
 				"be set at the same time as fee_rate.",
 		},
-		cli.Int64Flag{
+		cli.Uint64Flag{
 			Name: "time_lock_delta",
 			Usage: "the CLTV delta that will be applied to all " +
 				"forwarded HTLCs",
@@ -2080,6 +2081,25 @@ func parseChanPoint(s string) (*lnrpc.ChannelPoint, error) {
 	}, nil
 }
 
+// parseTimeLockDelta is expected to get a uint16 type of timeLockDelta,
+// which maximum value is MaxTimeLockDelta.
+func parseTimeLockDelta(timeLockDeltaStr string) (uint16, error) {
+	timeLockDeltaUnCheck, err := strconv.ParseUint(
+		timeLockDeltaStr, 10, 64,
+	)
+	if err != nil {
+		return 0, fmt.Errorf("failed to parse time_lock_delta: %s "+
+			"to uint64, err: %v", timeLockDeltaStr, err)
+	}
+
+	if timeLockDeltaUnCheck > routing.MaxCLTVDelta {
+		return 0, fmt.Errorf("time_lock_delta is too big, "+
+			"max value is %d", routing.MaxCLTVDelta)
+	}
+
+	return uint16(timeLockDeltaUnCheck), nil
+}
+
 func updateChannelPolicy(ctx *cli.Context) error {
 	ctxc := getContext()
 	client, cleanUp := getClient(ctx)
@@ -2089,7 +2109,7 @@ func updateChannelPolicy(ctx *cli.Context) error {
 		baseFee       int64
 		feeRate       float64
 		feeRatePpm    uint64
-		timeLockDelta int64
+		timeLockDelta uint16
 		err           error
 	)
 	args := ctx.Args()
@@ -2127,12 +2147,15 @@ func updateChannelPolicy(ctx *cli.Context) error {
 
 	switch {
 	case ctx.IsSet("time_lock_delta"):
-		timeLockDelta = ctx.Int64("time_lock_delta")
-	case args.Present():
-		timeLockDelta, err = strconv.ParseInt(args.First(), 10, 64)
+		timeLockDeltaStr := ctx.String("time_lock_delta")
+		timeLockDelta, err = parseTimeLockDelta(timeLockDeltaStr)
 		if err != nil {
-			return fmt.Errorf("unable to decode time_lock_delta: %v",
-				err)
+			return err
+		}
+	case args.Present():
+		timeLockDelta, err = parseTimeLockDelta(args.First())
+		if err != nil {
+			return err
 		}
 
 		args = args.Tail()

config.go

@@ -98,6 +98,10 @@ const (
 	// HTLCs on our channels.
 	minTimeLockDelta = routing.MinCLTVDelta
 
+	// MaxTimeLockDelta is the maximum CLTV delta that can be applied to
+	// forwarded HTLCs.
+	MaxTimeLockDelta = routing.MaxCLTVDelta
+
 	// defaultAcceptorTimeout is the time after which an RPCAcceptor will time
 	// out and return false if it hasn't yet received a response.
 	defaultAcceptorTimeout = 15 * time.Second

docs/release-notes/release-notes-0.16.1.md

@@ -4,6 +4,10 @@
 
 * The `lncli wallet psbt fund` command now allows users to specify the
   [`--min_confs` flag](https://github.com/lightningnetwork/lnd/pull/7510).
+ 
+* [Add time_lock_delta overflow check for UpdateChannelPolicy](https://github.com/lightningnetwork/lnd/pull/7350)
+  that ensure `time_lock_delta` is greater or equal than `0` and less or equal than `65535`
+
 
 ## Watchtowers
 

lnrpc/invoicesrpc/addinvoice.go

@@ -348,7 +348,7 @@ func AddInvoice(ctx context.Context, cfg *AddInvoiceConfig,
 	// We'll use our current default CLTV value unless one was specified as
 	// an option on the command line when creating an invoice.
 	switch {
-	case invoice.CltvExpiry > math.MaxUint16:
+	case invoice.CltvExpiry > routing.MaxCLTVDelta:
 		return nil, nil, fmt.Errorf("CLTV delta of %v is too large, "+
 			"max accepted is: %v", invoice.CltvExpiry,
 			math.MaxUint16)

routing/router.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	goErrors "errors"
 	"fmt"
+	"math"
 	"runtime"
 	"strings"
 	"sync"
@@ -80,6 +81,10 @@ const (
 	// bitcoin (160 for litecoin), though we now clamp the lower end of this
 	// range for user-chosen deltas to 18 blocks to be conservative.
 	MinCLTVDelta = 18
+
+	// MaxCLTVDelta is the maximum CLTV value accepted by LND for all
+	// timelock deltas.
+	MaxCLTVDelta = math.MaxUint16
 )
 
 var (

rpcserver.go

@@ -6827,6 +6827,10 @@ func (r *rpcServer) UpdateChannelPolicy(ctx context.Context,
 		return nil, fmt.Errorf("time lock delta of %v is too small, "+
 			"minimum supported is %v", req.TimeLockDelta,
 			minTimeLockDelta)
+	} else if req.TimeLockDelta > uint32(MaxTimeLockDelta) {
+		return nil, fmt.Errorf("time lock delta of %v is too big, "+
+			"maximum supported is %v", req.TimeLockDelta,
+			MaxTimeLockDelta)
 	}
 
 	baseFeeMsat := lnwire.MilliSatoshi(req.BaseFeeMsat)