storage-gas.md

Lack of check for storage expansion

Configuration

• detector id: storage-gas
• severity: low

Description

Each time the state grows, it should be ensured that there is enough Balance to cover the expansion.

Sample code

In the following code, storage usage expands after the insertion to self.banks, the difference should be checked to ensure the storage fee attached by the caller is enough.

let prev_storage = env::storage_usage();

self.banks.insert(&Bank {
    owner: bank.owner,
    balance: bank.balance.0,
});

assert!(
    env::attached_deposit() > ((env::storage_usage() - prev_storage) as u128 * env::storage_byte_cost()),
    "insufficient storage gas"
);