ID: 39367
User updated by: j at pureftpd dot org
-Summary: symbolic links should not be inserted into the
realpath cache
Reported By: j at pureftpd dot org
Status: Open
Bug Type: Filesystem function related
Operating System: Any
PHP Version: 5.2.0
New Comment:
I think the real bug is that unlink(), rename() and rmdir()
don't refresh the related realpath cache entries.
Here's a patch that fixes this, also available from ftp://
ftp.c9x.org/misc/
php_sync_realpath_cache_with_unlink_and_rename.diff
--- TSRM/tsrm_virtual_cwd.c.orig Sat Nov 4 00:56:05
2006
+++ TSRM/tsrm_virtual_cwd.c Sat Nov 4 02:53:13 2006
@@ -361,6 +361,23 @@
}
+CWD_API int realpath_cache_delete(const char *path, int
path_len) {
+ unsigned long key = realpath_cache_key(path,
path_len);
+ unsigned long n = key % (sizeof(CWDG
(realpath_cache)) / sizeof(CWDG(realpath_cache)[0]));
+ realpath_cache_bucket **bucket = &CWDG
(realpath_cache)[n];
+
+ while (*bucket != NULL) {
+ if (key == (*bucket)->key && path_len ==
(*bucket)->path_len &&
+ memcmp(path, (*bucket)->path,
path_len) == 0) {
+ realpath_cache_bucket *r = *bucket;
+ *bucket = (*bucket)->next;
+ CWDG(realpath_cache_size) -= sizeof
(realpath_cache_bucket) + r->path_len + 1 + r->realpath_len
+ 1;
+ free(r);
+ }
+ }
+ return 0;
+}
+
/* Resolve path relatively to state and put the real path
into state */
/* returns 0 for ok, 1 for error */
CWD_API int virtual_file_ex(cwd_state *state, const char
*path, verify_path_func verify_path, int use_realpath)
--- TSRM/tsrm_virtual_cwd.h.orig Sat Nov 4 02:39:04
2006
+++ TSRM/tsrm_virtual_cwd.h Sat Nov 4 02:48:04 2006
@@ -232,14 +232,14 @@
#define VCWD_CHDIR_FILE(path) virtual_chdir_file(path,
virtual_chdir TSRMLS_CC)
#define VCWD_GETWD(buf)
#define VCWD_REALPATH(path, real_path) virtual_realpath
(path, real_path TSRMLS_CC)
-#define VCWD_RENAME(oldname, newname) virtual_rename
(oldname, newname TSRMLS_CC)
+#define VCWD_RENAME(oldname, newname) (virtual_rename
(oldname, newname TSRMLS_CC) + realpath_cache_delete
(oldname, strlen(oldname)) + realpath_cache_delete(newname,
strlen(newname)))
#define VCWD_STAT(path, buff) virtual_stat(path, buff
TSRMLS_CC)
#if !defined(TSRM_WIN32)
#define VCWD_LSTAT(path, buff) virtual_lstat(path, buff
TSRMLS_CC)
#endif
-#define VCWD_UNLINK(path) virtual_unlink(path TSRMLS_CC)
+#define VCWD_UNLINK(path) (virtual_unlink(path TSRMLS_CC) +
realpath_cache_delete(path, strlen(path)))
#define VCWD_MKDIR(pathname, mode) virtual_mkdir(pathname,
mode TSRMLS_CC)
-#define VCWD_RMDIR(pathname) virtual_rmdir(pathname
TSRMLS_CC)
+#define VCWD_RMDIR(pathname) (virtual_rmdir(pathname
TSRMLS_CC) + realpath_cache_delete(pathname, strlen
(pathname)))
#define VCWD_OPENDIR(pathname) virtual_opendir(pathname
TSRMLS_CC)
#define VCWD_POPEN(command, type) virtual_popen(command,
type TSRMLS_CC)
#define VCWD_ACCESS(pathname, mode) virtual_access
(pathname, mode TSRMLS_CC)
@@ -261,15 +261,15 @@
#define VCWD_OPEN(path, flags) open(path, flags)
#define VCWD_OPEN_MODE(path, flags, mode) open(path,
flags, mode)
#define VCWD_CREAT(path, mode) creat(path, mode)
-#define VCWD_RENAME(oldname, newname) rename(oldname,
newname)
+#define VCWD_RENAME(oldname, newname) (rename(oldname,
newname) + realpath_cache_delete(oldname, strlen(oldname)) +
realpath_cache_delete(newname, strlen(newname)))
#define VCWD_CHDIR(path) chdir(path)
#define VCWD_CHDIR_FILE(path) virtual_chdir_file(path,
chdir)
#define VCWD_GETWD(buf) getwd(buf)
#define VCWD_STAT(path, buff) stat(path, buff)
#define VCWD_LSTAT(path, buff) lstat(path, buff)
-#define VCWD_UNLINK(path) unlink(path)
+#define VCWD_UNLINK(path) (unlink(path) +
realpath_cache_delete(path, strlen(path)))
#define VCWD_MKDIR(pathname, mode) mkdir(pathname, mode)
-#define VCWD_RMDIR(pathname) rmdir(pathname)
+#define VCWD_RMDIR(pathname) (rmdir(pathname) +
realpath_cache_delete(pathname, strlen(pathname)))
#define VCWD_OPENDIR(pathname) opendir(pathname)
#define VCWD_POPEN(command, type) popen(command, type)
#if defined(TSRM_WIN32)
Previous Comments:
------------------------------------------------------------------------
[2006-11-04 00:09:00] j at pureftpd dot org
Description:
------------
realpath() on a symlink returns the final file the link
points to.
Caching symbolic links through the realpath cache can cause
unexpected behaviors.
Here's a fix against PHP 5.2.0
--- TSRM/tsrm_virtual_cwd.c.orig Sat Nov 4 00:56:05
2006
+++ TSRM/tsrm_virtual_cwd.c Sat Nov 4 00:58:03 2006
@@ -562,7 +562,11 @@
}
if (use_realpath && CWDG(realpath_cache_size_limit))
{
- realpath_cache_add(path, path_length, state-
>cwd, state->cwd_length, t TSRMLS_CC);
+ struct stat buf;
+
+ if (lstat(path, &buf) == 0 && !S_ISLNK
(buf.st_mode)) { +
realpath_cache_add(path, path_length, state->cwd, state-
>cwd_length, t TSRMLS_CC);
+ }
}
if (verify_path && verify_path(state)) {
Reproduce code:
---------------
See bug #36555, or that code :
<?php
@unlink('/tmp/1link');
@unlink('/tmp/1tmp');
@unlink('/tmp/testfile1');
file_put_contents('/tmp/testfile1', '42');
symlink('/tmp/testfile1', '/tmp/1tmp');
rename('/tmp/1tmp', '/tmp/1link');
$a = file_get_contents('/tmp/1link');
var_dump($a);
unlink('/tmp/1link');
clearstatcache();
$a = file_get_contents('/tmp/1link');
var_dump($a);
?>
Expected result:
----------------
The second file_get_contents() should fail because /tmp/1link
has been unlinked.
But it doesn't.
Actual result:
--------------
42
42
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=39367&edit=1
