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DV.Generic.Mutable.fill does not check for out of bounds access

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#118 10 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
haskell
Domain
data

Research direction

Start with Data.Vector.Generic.Mutable.fill and reproduce the failure using the Haskell snippet in the issue. Check how the mutable vector and stream bounds are handled, then establish whether the function should reject excess input or be explicitly unsafe; done means the reproduction no longer causes out-of-bounds memory access.

Written by the indexing model from the issue text.

Description

bug design-shed

So it should be either renamed as unsafeFill and/or bound checks added. It's possible this is not only one function with unsafe access.

module Fill where

import qualified Data.Vector.Unboxed.Mutable       as MU
import qualified Data.Vector.Generic.Mutable       as MG
import qualified Data.Vector.Fusion.Stream.Monadic as SS

main :: IO ()
main = do
  mv <- MU.replicate 10 (1 :: Int)
  MG.fill mv (SS.replicate 1000000 42)
  return ()
[1 of 1] Compiling Fill             ( /home/alexey/qqq/fill-sigsegv.hs, interpreted )
Ok, modules loaded: Fill.
*Fill> :main
Segmentation fault
Dominant language
Haskell
Stars
401
Forks
145
PR merge metrics
No merged PRs in 30d

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