drepper@redhat.com <drepper@redhat.com> wrote, on 08 Jun 2009:
>
> @ page 75 line 2147 section Pathname objection {ud-filename-colon}
>
> Problem:
>
> Edition of Specification (Year): 2008
>
> Defect code : 2. Omission
>
> The location of the bug is actually one place that is effected. And I'm not
>sure where the final solution will apply.
>
> The problem is the definition of PATH and similar environment variables and
>similar concepts.
>
> The definition of PATH says:
>
> This variable shall represent the sequence of path prefixes that certain
>functions and utilities apply in searching for an executable
> file known only by a filename. The prefixes shall be separated by a
> <colon> (':').
>
>
> The definition of path prefix refers to pathname which in turn refers
> to filename for the actual content of the string and the filename
> definition says:
>
> The
>characters composing the name may be selected from the set of
> all character values excluding the <slash> character and the null
> byte.
>
>
> I.e., the path components are not disallowed to contain colons. This
> makes it impossible to handle the pathname components correctly. The
> shell, execvp(), etc only see a string and cannot differentiate
> between colons in pathname components and those between the paths
> components.
>
>
> We have to restrict filenames used in paths. I think restricting
> pathname to pathname components and then define pathname components
> appropriately.
>
>
> This problem spreads far beyond POSIX's use of path.
>
> Action:
>
> Change page 76, line 2053 to:
>
> A filename not containing a colon (':').
>
>
> Change page 75, line 2147 from:
>
> [..] followed by zero or more filenames separated [...]
>
> to
>
> [..] followed by zero or more pathname components separated [...]
This is the wrong way to go about fixing this. You are trying to
fix a high-level problem by breaking low-level things. At the low
level of things like open() there is no problem with pathnames
containing colons. The problems are at a higher level and should
be fixed at that level.
In the specific case of PATH, a suitable fix would be to change
"The prefixes shall be separated by a <colon> (':')."
to
"The prefixes shall be separated by a <colon> (':'), and
consequently in order for the value of PATH to be interpreted
correctly the prefixes can not contain any <colon> characters."
--
Geoff Clare <g.clare@opengroup.org>
The Open Group, Thames Tower, Station Road, Reading, RG1 1LX, England
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