CertiK: KyberSwap vulnerability exists in the implementation of Elastic's computeSwapStep() function

CertiK posted on social media that the vulnerability being attacked by KyberSwap exists in the implementation of the computeSwapStep() function of KyberSwap Elastic. This function calculates the actual exchange input/output amount to be deducted or added, the exchange fee to be charged, and the resulting sqrtP. The function first calls the calcReachAmount() function, concluding that the attacker's swap will not cross the tick mark, but mistakenly produces a slightly larger price than the targetSqrtP calculated by calling "calcFinalPrice". Therefore, liquidity was not removed, leading to the attack. The attacker performed sophisticated computational operations on liquidity pools in the empty tick range, leveraging cross-swapping liquidity counts, depleting many KyberSwap pools containing low liquidity.