diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp index 0569e748f..88ecb2dad 100644 --- a/src/cryptonote_core/blockchain.cpp +++ b/src/cryptonote_core/blockchain.cpp @@ -2713,7 +2713,11 @@ leave: // populate various metadata about the block to be stored alongside it. block_size = cumulative_block_size; cumulative_difficulty = current_diffic; - already_generated_coins = already_generated_coins + base_reward; + // In the "tail" state when the minimum subsidy (implemented in get_block_reward) is in effect, the number of + // coins will eventually exceed MONEY_SUPPLY and overflow a uint64. To prevent overflow, cap already_generated_coins + // at MONEY_SUPPLY. already_generated_coins is only used to compute the block subsidy and MONEY_SUPPLY yields a + // subsidy of 0 under the base formula and therefore the minimum subsidy >0 in the tail state. + already_generated_coins = base_reward < (MONEY_SUPPLY-already_generated_coins) ? already_generated_coins + base_reward : MONEY_SUPPLY; if(m_db->height()) cumulative_difficulty += m_db->get_block_cumulative_difficulty(m_db->height() - 1);