fix: F-2026-18194 | [Dual Defense] Unbacked Gas PRC20 Mint on INBOUND_REVERT via applyGasRefund

test/integration/uexecutor/gas_refund_test.go

@@ -0,0 +1,40 @@
+package integrationtest
+
+import (
+	"testing"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/stretchr/testify/require"
+
+	utils "github.com/pushchain/push-chain-node/test/utils"
+	uexecutortypes "github.com/pushchain/push-chain-node/x/uexecutor/types"
+)
+
+// TestInboundRevertGasNotRefunded proves an INBOUND_REVERT never refunds gas on
+// settlement. A revert is protocol-initiated — the user was never charged a gas fee
+// for it — so even when a GasFee budget is present (PRC20 reverts set one) and the
+// observed gasFeeUsed is well below it, no refund must be attempted.
+func TestInboundRevertGasNotRefunded(t *testing.T) {
+	chainApp, ctx, vals, utxId, ob, coreVals := setupOutboundVotingTest(t, 4)
+
+	// Make the seeded outbound an INBOUND_REVERT carrying a gas budget with headroom
+	// that would otherwise trigger a refund (GasFee 1000, gasFeeUsed 100 below).
+	ob.TxType = uexecutortypes.TxType_INBOUND_REVERT
+	ob.GasFee = "1000"
+	ob.GasToken = "0x000000000000000000000000000000000000C0dE"
+	require.NoError(t, chainApp.UexecutorKeeper.UpdateOutbound(ctx, utxId, *ob))
+
+	// Settle it successfully with gasFeeUsed << GasFee.
+	for i := 0; i < 3; i++ {
+		valAddr, err := sdk.ValAddressFromBech32(coreVals[i].OperatorAddress)
+		require.NoError(t, err)
+		require.NoError(t, utils.ExecVoteOutbound(
+			t, ctx, chainApp, vals[i], sdk.AccAddress(valAddr).String(), utxId, ob, true, "", "100"))
+	}
+
+	utx, found, err := chainApp.UexecutorKeeper.GetUniversalTx(ctx, utxId)
+	require.NoError(t, err)
+	require.True(t, found)
+	require.Nil(t, utx.OutboundTx[0].PcRefundExecution,
+		"INBOUND_REVERT must not attempt a gas refund — the user was never charged for it")
+}

x/uexecutor/keeper/outbound.go

@@ -176,6 +176,14 @@ func (k Keeper) handleSuccessfulOutbound(ctx sdk.Context, utxId string, outbound
 // It is called for both successful and failed outbounds — gas is consumed on the
 // external chain regardless of execution outcome.
 func (k Keeper) applyGasRefund(ctx sdk.Context, outbound *types.OutboundTx, obs *types.OutboundObservation) {
+	// INBOUND_REVERT is protocol-initiated: the user was never charged a gas fee for
+	// the revert, so its GasFee (when present) is only a relayer gas hint, not a
+	// user-paid budget. Refunding "excess" would hand the user funds they never paid,
+	// so never refund for a revert — regardless of PC20/PRC20 or whether GasFee is set.
+	if outbound.TxType == types.TxType_INBOUND_REVERT {
+		return
+	}
+
 	if obs.GasFeeUsed == "" || outbound.GasFee == "" || outbound.GasToken == "" {
 		return
 	}