🚀 go-pugleaf

VERSION:
	getwd.c 5.2 (Berkeley) 3/9/86

CLIENT MACHINE:
	VAX 11/780

CLIENT OPERATING SYSTEM:
	BSD UNIX 4.3 Release ???

SYNOPSIS:
	Misplaced library call closedir() in getwd().

DESCRIPTION:
	The problem arises when the function prepend() is trying to access the
	file name which is a segment of memory allocated within the opendir()
	function call. This segment, however, is no longer valid if closedir()
	function call is issued.
	
REPEAT-BY:
	This bug can only be demonstrated with your own malloc package instead
	of the standard one. The malloc package has to be able to either erase
	the memory to be freed with junk data or release the memory back to
	the system (via sbrk(2)).

FIX:
	Just swap two lines.

*** /usr/src/lib/libc/gen/getwd.c	Mon Mar 10 14:49:35 1986
--- getwd.c	Wed Jul 27 09:52:24 1988
***************
*** 85,92 ****
  				strcpy(dptr, dir->d_name);
  				lstat(curdir, &dd);
  			} while(dd.st_ino != cino || dd.st_dev != cdev);
- 		closedir(dirp);
  		pnptr = prepend("/", prepend(dir->d_name, pnptr));
  	}
  	if (*pnptr == '\0')		/* current dir == root dir */
  		strcpy(pathname, "/");
--- 85,93 ----
  				strcpy(dptr, dir->d_name);
  				lstat(curdir, &dd);
  			} while(dd.st_ino != cino || dd.st_dev != cdev);
  		pnptr = prepend("/", prepend(dir->d_name, pnptr));
+ 		/* Now is save to close the directory pointer */
+ 		closedir(dirp);
  	}
  	if (*pnptr == '\0')		/* current dir == root dir */
  		strcpy(pathname, "/");

---------------------

       _   _. __   _,
---   /_)_(__/) )_(_)_		[ Also know as Andrew ]
     /              /|
    '              |/

----------------
Po Cheung NG                               ISD:  +61 2 697-4056
JMRC, School of Elec. Eng. and Comp. Sci., STD:  (02) 697-4056
The University of New South Wales,         FAX:  +61 2 662-2087
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