Flashloans - Githubissues

mrgnlabs / marginfi-v2

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Flashloans #121

Closed jkbpvsc closed 8 months ago

jkbpvsc commented 1 year ago

Flashloans

Flashloans only work for accounts that have a flag manually set for them by a group admin

How they work

Flashloans work by deferring health checks for an account to the end of the flashloan. This is achieved with two new instructions. flashloan_start and flashloan_end.

flashloan_start - performs a number of security checks, set the IN_FLASHLOAN_FLAG
flashloan_end - checks the account health, and clears the IN_FLASHLOAN_FLAG

Security checklist

end_flashloan ix index is after start_flashloan ix index
Ixs has an end_flashloan ix present
end_flashloan ix is for the marginfi program
end_flashloan ix is for the same marginfi account
Account is not disabled
Account is not already in a flashloan

Considerations

What happens if you flashloan multiple accounts in a single tx?
Can you corrupt bank parameters by artificially changing the utilization rate in a bank.

jkbpvsc commented 12 months ago

One consideration I'm having is if we should have all the borrows and repays happen in the fl_start and fl_end ixs, to prevent any unexpected combinations of flashloan ixs and bank state updates. Thoughts @losman0s?