[GHC] #229: Integer overflow in array allocation

[GHC]

#229: Integer overflow in array allocation
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        Reporter:  josefs             |            Owner:  rwbarton
            Type:  bug                |           Status:  new
        Priority:  normal             |        Milestone:  ⊥
       Component:  libraries (other)  |          Version:  7.8.1
      Resolution:                     |         Keywords:
Operating System:  Unknown/Multiple   |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown       |       Difficulty:  Unknown
       Test Case:                     |       Blocked By:
        Blocking:                     |  Related Tickets:
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Changes (by rwbarton):

 * owner:   => rwbarton
 * priority:  low => normal
 * version:  6.4.1 => 7.8.1
 * component:  libraries/base => libraries (other)


Comment:

 This bug still exists. With a little more care you can read and write
 arbitrary memory.

 {{{
 import Data.Array.MArray
 import Data.Array.IO
 import Data.Word

 main = do
   m <- newArray_ (0,2^62-1) :: IO (IOUArray Int Word32) -- allocates 0
 bytes
   writeArray m 17 12345 -- write wherever you like
 }}}

 The `unsafeNewArray_` definitions in `Data.Array.Base` need to check for
 integer overflow when computing the size in bytes to be allocated.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/229#comment:15>
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