[Python-checkins] python/dist/src/Lib os.py,1.47,1.47.4.1

2002年8月08日 12:46:55 -0700

Update of /cvsroot/python/python/dist/src/Lib
In directory usw-pr-cvs1:/tmp/cvs-serv28586
Modified Files:
 Tag: release21-maint
	os.py 
Log Message:
Backport of SF patch 590294: os._execvpe security fix (Zack Weinberg).
1) Do not attempt to exec a file which does not exist
just to find out what error the operating system
returns. This is an exploitable race on all platforms
that support symbolic links.
2) Immediately re-raise the exception if we get an
error other than errno.ENOENT or errno.ENOTDIR. This
may need to be adapted for other platforms.
Index: os.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/os.py,v
retrieving revision 1.47
retrieving revision 1.47.4.1
diff -C2 -d -r1.47 -r1.47.4.1
*** os.py	7 Mar 2001 09:05:44 -0000	1.47
--- os.py	8 Aug 2002 19:46:52 -0000	1.47.4.1
***************
*** 302,307 ****
 __all__.extend(["execl","execle","execlp","execlpe","execvp","execvpe"])
 
- _notfound = None
 def _execvpe(file, args, env=None):
 if env is not None:
 func = execve
--- 302,308 ----
 __all__.extend(["execl","execle","execlp","execlpe","execvp","execvpe"])
 
 def _execvpe(file, args, env=None):
+ from errno import ENOENT, ENOTDIR
+ 
 if env is not None:
 func = execve
***************
*** 311,315 ****
 argrest = (args,)
 env = environ
! global _notfound
 head, tail = path.split(file)
 if head:
--- 312,316 ----
 argrest = (args,)
 env = environ
! 
 head, tail = path.split(file)
 if head:
***************
*** 321,339 ****
 envpath = defpath
 PATH = envpath.split(pathsep)
- if not _notfound:
- if sys.platform[:4] == 'beos':
- # Process handling (fork, wait) under BeOS (up to 5.0)
- # doesn't interoperate reliably with the thread interlocking
- # that happens during an import. The actual error we need
- # is the same on BeOS for posix.open() et al., ENOENT.
- try: unlink('/_#.# ## #.#')
- except error, _notfound: pass
- else:
- import tempfile
- t = tempfile.mktemp()
- # Exec a file that is guaranteed not to exist
- try: execv(t, ('blah',))
- except error, _notfound: pass
- exc, arg = error, _notfound
 for dir in PATH:
 fullname = path.join(dir, file)
--- 322,325 ----
***************
*** 341,348 ****
 apply(func, (fullname,) + argrest)
 except error, (errno, msg):
! if errno != arg[0]:
! exc, arg = error, (errno, msg)
! raise exc, arg
! 
 
 # Change environ to automatically call putenv() if it exists
--- 327,333 ----
 apply(func, (fullname,) + argrest)
 except error, (errno, msg):
! if errno != ENOENT and errno != ENOTDIR:
! raise
! raise error, (errno, msg)
 
 # Change environ to automatically call putenv() if it exists