Numeric types’ Read instances use exponential CPU/memory
Computing
read "1e99999999" :: Int -- returns 0 read "1e99999999" :: Integer -- returns [REDACTED] read "1e99999999" :: Float -- returns Infinity read "1e99999999" :: Double -- returns Infinity
takes rather a lot of CPU time and memory, and adding more digits to the exponent makes it take exponentially more. In some applications, this behavior could be exploitable as a denial of service.
I’m not sure what the right solution is for Integer, but clearly all the other cases should be optimized to produce 0 or Infinity very quickly.
Trac metadata
Trac field | Value |
---|---|
Version | 7.4.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/base |
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