#7161: hSetNewlineMode and hSetEncoding can be performed on closed and semi-closed handles -------------------------------------+------------------------------------- Reporter: duncan | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Core Libraries | Version: 7.6.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * status: infoneeded => new * cc: ekmett (added) Old description:

The `hSetNewlineMode` and `hSetEncoding` functions from `GHC/IO/Handle.hs` do not check that the Handle is in an open mode. It is possible to use them on closed handles. hSetEncoding on a closed Handle triggers a segfault. Similarly, the operations are also both possible on semi-closed handles, and given the way hGetContents is implemented, this will affect the result of hGetContents which is clearly against the intention of the hGetContents/semi-closed stuff.

Both functions use the `withAllHandles__` helper. Unlike similar helpers like `wantReadableHandle_` this one doesn't do any handle mode checking.

Additionally, `hSetBuffering` and `hSetBinary` mode also use the `withAllHandles__` pattern and don't obviously check for an open handle but I've not verified this.

New description: The `hSetNewlineMode` and `hSetEncoding` functions from `GHC/IO/Handle.hs` do not check that the Handle is in an open mode. It is possible to use them on closed handles. hSetEncoding on a closed Handle triggers a segfault. Similarly, the operations are also both possible on semi-closed handles, and given the way hGetContents is implemented, this will affect the result of hGetContents which is clearly against the intention of the hGetContents/semi-closed stuff. Both functions use the `withAllHandles__` helper. Unlike similar helpers like `wantReadableHandle_` this one doesn't do any handle mode checking. Additionally, `hSetBuffering` and `hSetBinaryMode` mode also use the `withAllHandles__` pattern and don't obviously check for an open handle but I've not verified this. -- Comment: With or without segfaults, this could be fixed. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7161#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler