[GHC] #8058: If .ghci is a symlink, permissions aren't read correctly

[GHC]

#8058: If .ghci is a symlink, permissions aren't read correctly
-------------------------------+-------------------------------------------
        Reporter:  berdario    |            Owner:
            Type:  bug         |           Status:  closed
        Priority:  low         |        Milestone:
       Component:  GHCi        |          Version:  7.6.2
      Resolution:  invalid     |         Keywords:
Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple             |       Difficulty:  Easy (less than 1 hour)
 Type of failure:  Other       |       Blocked By:
       Test Case:              |  Related Tickets:
        Blocking:              |
-------------------------------+-------------------------------------------
Changes (by leroux):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 Reformatted output from berdario:
 {{{
 $ ls -l .ghci
 lrwxrwxrwx 1 dario dario 40 Jul 14 15:27 .ghci ->
 /home/dario/.dotfiles/dotfiles/ghci.conf

 $ ls -l (readlink -f .ghci)
 -rw-r--r-- 1 dario dario 10 Jul 14 15:25
 /home/dario/.dotfiles/dotfiles/ghci.conf

 $ ghci
 GHCi, version 7.6.2: http://www.haskell.org/ghc/ :? for help
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 Loading package base ... linking ... done.
 * WARNING: /home/dario/.dotfiles/dotfiles is writable by someone else,
 IGNORING!
 Prelude>
 }}}

 The attacker could symlink `.ghci` to another file which has malicious
 code.

 ----

 Output from my system:
 {{{
 $ ls -l .ghci
 lrwxr-xr-x  1 leroux  staff  44 Jul 30 10:02 .ghci ->
 /Users/leroux/.dotfiles/haskell/ghci.symlink

 $ ls -l `readlink .ghci`
 -rwxr-x---  1 leroux  staff  338 Sep 22 18:59
 /Users/leroux/.dotfiles/haskell/ghci.symlink
 }}}

 ----

 Fix:
 {{{
 $ chmod 755 .ghci
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8058#comment:2>
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