[Bug libc/13253] New: fileno(3) crashes when passed NULL argument

["klimes at centrum dot cz" <sourceware-bugzilla at sourceware dot org>]

http://sourceware.org/bugzilla/show_bug.cgi?id=13253

             Bug #: 13253
           Summary: fileno(3) crashes when passed NULL argument
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
        AssignedTo: drepper.fsp@gmail.com
        ReportedBy: klimes@centrum.cz
    Classification: Unclassified


fileno() crashes when passed NULL, e.g. due to these construct:
fileno(fopen("no-existent", "r");

http://pubs.opengroup.org/onlinepubs/009695399/functions/fileno.html says:
...Otherwise, the value -1 shall be returned and errno set to indicate the
error...

man 3 fileno says:
ERRORS
       These functions should not fail and do not set the external variable
errno.  (However, in case fileno() detects that its argument is not a valid
stream, it  must  return  -1  and  set  errno  to EBADF.)

I think it should rather detect the invalid argument and return -1 with errno
set to EBADF as docs suggest.

Looking into source it is evident that CHECK_FILE (fp, EOF); macro call in
fileno() doesn't check the stream (is no-operation). That's just done for cases
when compiled with IO_DEBUG, which is not defined in production.  The
CHECK_FILE macro should always check validity of the passed fp parameter.

Moreover 'EOF' in the macro call should be replaced with -1 as it is the error
return value.

Referenced files:
libio/libioP.h
libio/fileno.c

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