Albort - Inconsistent Reserve Checks for Fee Deduction

[sherlock-admin4]

Albort

Medium

Inconsistent Reserve Checks for Fee Deduction

Summary

The reserve checks for the swap fee are only performed when woopool_from.token_mint != woopool_from.quote_token_mint.

Vulnerability Detail

• When swapping from a base token to the quote token, the fee is deducted from the quote amount, and the protocol needs to ensure that the quote pool has enough reserve to cover the fee.
• However, when swapping from the quote token to a base token, the fee is also deducted from the quote amount, but the reserve check is not performed in this case.
  This inconsistency could lead to situations where the protocol cannot cover the fee from its reserves.

Impact

Code Snippet

https://github.com/sherlock-audit/2024-08-woofi-solana-deployment/blob/main/WOOFi_Solana/programs/woofi/src/instructions/query.rs#L118

Tool used

Manual Review

Recommendation

Perform the reserve check for the swap fee regardless of the token being swapped from or to.

[toprince]

Not valid.
Same with previous one.
swap_fee is x% of from amount, and already checked that