Submitted by adriro, also found by immeas and bin2chen
Some ERC20 implementations revert on zero value transfers. Since liquidation rewards are based on a fraction of the available positions premiums, this may cause an accidental denial of service that prevents the successful execution of liquidations.
Liquidations in the LAMM protocol are incentivized by a reward that is calculated as a fraction of the premiums available in the position.
https://github.com/code-423n4/2023-12-particle/blob/a3af40839b24aa13f5764d4f84933dbfa8bc8134/contracts/protocol/ParticlePositionManager.sol#L348-L354
These amounts are later transferred to the caller, the liquidator, at the end of the liquidatePosition() function.
https://github.com/code-423n4/2023-12-particle/blob/a3af40839b24aa13f5764d4f84933dbfa8bc8134/contracts/protocol/ParticlePositionManager.sol#L376-L378
Reward amounts, liquidationRewardFrom and liquidationRewardTo, can be calculated as zero if tokenFromPremium or tokenToPremium are zero, if the liquidation ratio gets rounded down to zero, or if LIQUIDATION_REWARD_FACTOR is zero.
Coupled with that fact that some ERC20 implementations revert on zero value transfers, this can cause an accidental denial of service in the implementation of liquidatePosition(), blocking certain positions from being liquidated.
Check that the amounts are greater than zero before executing the transfer.
0xleastwood (Judge) commented:
wukong-particle (Particle) commented:
adriro (Warden) commented:
0xleastwood (Judge) commented:
 wukong-particle (Particle) confirmed
