svn commit: r246641 - head/lib/libc/gen

[Jilles Tjoelker]

Author: jilles
Date: Sun Feb 10 23:09:15 2013
New Revision: 246641
URL: http://svnweb.freebsd.org/changeset/base/246641

Log:
  fts: Use O_DIRECTORY when opening name that might be changed by attacker.
  
  There are uncommon cases where fts_safe_changedir() may be called with a
  non-NULL name that is not "..". Do not block or worse if an attacker put (a
  (symlink to) a fifo or device where a directory used to be.
  
  MFC after:	1 week

Modified:
  head/lib/libc/gen/fts.c

Modified: head/lib/libc/gen/fts.c
==============================================================================
--- head/lib/libc/gen/fts.c	Sun Feb 10 22:06:06 2013	(r246640)
+++ head/lib/libc/gen/fts.c	Sun Feb 10 23:09:15 2013	(r246641)
@@ -1119,7 +1119,8 @@ fts_safe_changedir(FTS *sp, FTSENT *p, i
 	newfd = fd;
 	if (ISSET(FTS_NOCHDIR))
 		return (0);
-	if (fd < 0 && (newfd = _open(path, O_RDONLY | O_CLOEXEC, 0)) < 0)
+	if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY |
+	    O_CLOEXEC, 0)) < 0)
 		return (-1);
 	if (_fstat(newfd, &sb)) {
 		ret = -1;