Potential Precision Loss Due to Division Before Multiplication
Low/Info issue submitted by bigbick123456789000
Summary
see below
Vulnerability Detail
In the provided code snippet, a potential vulnerability arises due to the sequence of operations involving division followed by multiplication. Here's a detailed breakdown:
The highGasCharged and baseGasCharged variables represent certain gas-related parameters, and the lnWad function calculates the natural logarithm. However, the vulnerability lies in the fact that the division operation is performed before the multiplication. This sequence of operations can potentially lead to precision loss.
uint256 a = highGasCharged / baseGasCharged;: This division operation could introduce precision loss if the dividend (highGasCharged) or divisor (baseGasCharged) have fractional parts or if the result is not representable with sufficient precision in the uint256 data type.
uint256 lnA = uint256(FixedPointMathLib.lnWad(int256(a * FixedPointMathLib.WAD)));: Here, a is multiplied by FixedPointMathLib.WAD, which is used to convert it into fixed-point format. Then, the result is passed to the lnWad function. The multiplication operation could further compound any precision loss introduced by the division operation.
Impact
The impact of this vulnerability is that it can introduce inaccuracies or imprecisions in the calculated value of lnA. Depending on the specific values of highGasCharged and baseGasCharged, as well as the precision handling within the FixedPointMathLib library, the loss of precision could affect the accuracy of subsequent calculations or decisions based on the result.
Potential Precision Loss Due to Division Before Multiplication
Low/Info issue submitted by bigbick123456789000
Summary
see below
Vulnerability Detail
In the provided code snippet, a potential vulnerability arises due to the sequence of operations involving division followed by multiplication. Here's a detailed breakdown:
The
highGasChargedandbaseGasChargedvariables represent certain gas-related parameters, and thelnWadfunction calculates the natural logarithm. However, the vulnerability lies in the fact that the division operation is performed before the multiplication. This sequence of operations can potentially lead to precision loss.uint256 a = highGasCharged / baseGasCharged;: This division operation could introduce precision loss if the dividend (highGasCharged) or divisor (baseGasCharged) have fractional parts or if the result is not representable with sufficient precision in theuint256data type.uint256 lnA = uint256(FixedPointMathLib.lnWad(int256(a * FixedPointMathLib.WAD)));: Here, a is multiplied byFixedPointMathLib.WAD, which is used to convert it into fixed-point format. Then, the result is passed to thelnWadfunction. The multiplication operation could further compound any precision loss introduced by the division operation.Impact
The impact of this vulnerability is that it can introduce inaccuracies or imprecisions in the calculated value of
lnA. Depending on the specific values ofhighGasChargedandbaseGasCharged, as well as the precision handling within theFixedPointMathLiblibrary, the loss of precision could affect the accuracy of subsequent calculations or decisions based on the result.Code Snippet
FaultDisputeGame.sol#L604-L610
Tool used
Manual Review
Recommendation
The sequence of operations should be adjusted to prioritize multiplication before division.