core/vm: fix flaw in sstore refund

holiman · holiman · commit f38e80d6400e · 2020-09-25T09:34:50.000+02:00
diff --git a/core/vm/operations_acl.go b/core/vm/operations_acl.go
@@ -94,7 +94,10 @@ func gasSStoreEIP2929(evm *EVM, contract *Contract, stack *Stack, mem *Memory, m
 		} else { // reset to original existing slot (2.2.2.2)
 			// EIP 2200 Original clause:
 			//	evm.StateDB.AddRefund(params.SstoreResetGasEIP2200 - params.SloadGasEIP2200)
-			evm.StateDB.AddRefund(params.SstoreResetGasEIP2200 - WarmStorageReadCostEIP2929)
+			// - SSTORE_RESET_GAS redefined as (5000 - COLD_SLOAD_COST)
+			// - SLOAD_GAS redefined as WARM_STORAGE_READ_COST
+			// Final: (5000 - COLD_SLOAD_COST) - WARM_STORAGE_READ_COST
+			evm.StateDB.AddRefund((params.SstoreResetGasEIP2200 - ColdSloadCostEIP2929) - WarmStorageReadCostEIP2929)
 		}
 	}
 	// EIP-2200 original clause:

Original file line number	Diff line number	Diff line change
`@@ -94,7 +94,10 @@ func gasSStoreEIP2929(evm EVM, contract Contract, stack Stack, mem Memory, m`
`94`	`94`	`} else { // reset to original existing slot (2.2.2.2)`
`95`	`95`	`// EIP 2200 Original clause:`
`96`	`96`	`// evm.StateDB.AddRefund(params.SstoreResetGasEIP2200 - params.SloadGasEIP2200)`
`97`		`- evm.StateDB.AddRefund(params.SstoreResetGasEIP2200 - WarmStorageReadCostEIP2929)`
	`97`	`+ // - SSTORE_RESET_GAS redefined as (5000 - COLD_SLOAD_COST)`
	`98`	`+ // - SLOAD_GAS redefined as WARM_STORAGE_READ_COST`
	`99`	`+ // Final: (5000 - COLD_SLOAD_COST) - WARM_STORAGE_READ_COST`
	`100`	`+ evm.StateDB.AddRefund((params.SstoreResetGasEIP2200 - ColdSloadCostEIP2929) - WarmStorageReadCostEIP2929)`
`98`	`101`	`}`
`99`	`102`	`}`
`100`	`103`	`// EIP-2200 original clause:`