Submission Details
Severity:
Precision loss in `locals.newWeightsConverted` calculation
Summary
Dividing locals.normalizationFactor prematurely may cause precision loss if locals.sumKappa is very large or very small.
locals.normalizationFactor = locals.normalizationFactor.div(locals.sumKappa);
for (locals.i = 0; locals.i < _prevWeights.length; ) {
// w(t − 1) + κ ·(ℓp(t) − 1/p(t) · ∂p(t)/∂t)
int256 res = int256(_prevWeights[locals.i]) + int256(locals.kappa[locals.i]).mul(locals.normalizationFactor - locals.newWeights[locals.i]);
require(res >= 0, "Invalid weight");
newWeightsConverted[locals.i] = res;
unchecked {
++locals.i;
}
}
Impact
Incorrect Weight Calculations
Recommendations
-- locals.normalizationFactor = locals.normalizationFactor.div(locals.sumKappa);
for (locals.i = 0; locals.i < _prevWeights.length; ) {
// w(t − 1) + κ ·(ℓp(t) − 1/p(t) · ∂p(t)/∂t)
-- int256 res = int256(_prevWeights[locals.i]) + int256(locals.kappa[locals.i]).mul(locals.normalizationFactor - locals.newWeights[locals.i]);
++ int256 res = int256(_prevWeights[locals.i]) + int256(locals.kappa[locals.i]).mul(locals.normalizationFactor - locals.newWeights[locals.i].mul(locals.sumKappa)).div(locals.sumKappa);
require(res >= 0, "Invalid weight");
newWeightsConverted[locals.i] = res;
unchecked {
++locals.i;
}
}
Prize pool breakdown
Total prize
49,600 OP
nSLOC
3,00017
OP / LOC
44,640
4,960
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