From: Christoph M. Becker <cmbecker69@gmx.de>
Date: Mon, 19 Oct 2020 15:41:58 +0000 (+0200)
Subject: Fix #80258: Windows Deduplication Enabled, randon permission errors
X-Git-Tag: php-7.3.25RC1~12
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=848e24f24d7c05db04fe1ba87e6566a5c30323fd;p=php

Fix #80258: Windows Deduplication Enabled, randon permission errors

A recent bug fix regarding symlinks claimed:

> After resolving reparse points, the path still may be a reparse
> point; in that case we have to resolve that reparse point as well.

While that is basically correct, some reparse points may point to
inaccessible system folders (e.g. `IO_REPARSE_TAG_DEDUP` points to
"\System Volume Information").  Since we don't know details about
arbitrary reparse points, and are mainly interested in nested symlinks,
we take a step back, and only resolve `IO_REPARSE_TAG_SYMLINK` for now.

Close GH-6354.
---

diff --git a/NEWS b/NEWS
index a818b50641..1b5f8ee8dd 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,8 @@ PHP                                                                        NEWS
 - Core:
   . Fixed bug #80280 (ADD_EXTENSION_DEP() fails for ext/standard and ext/date).
     (cmb)
+  . Fixed bug #80258 (Windows Deduplication Enabled, randon permission errors).
+    (cmb)
 
 - IMAP:
   . Fixed bug #64076 (imap_sort() does not return FALSE on failure). (cmb)
diff --git a/Zend/zend_virtual_cwd.c b/Zend/zend_virtual_cwd.c
index 7c5ac825c5..b74313d3a5 100644
--- a/Zend/zend_virtual_cwd.c
+++ b/Zend/zend_virtual_cwd.c
@@ -741,7 +741,7 @@ CWD_API realpath_cache_bucket** realpath_cache_get_buckets(void)
 static size_t tsrm_realpath_r(char *path, size_t start, size_t len, int *ll, time_t *t, int use_realpath, int is_dir, int *link_is_dir) /* {{{ */
 {
 	size_t i, j;
-	int directory = 0, save;
+	int directory = 0, save, may_retry_reparse_point;
 #ifdef ZEND_WIN32
 	WIN32_FIND_DATAW dataw;
 	HANDLE hFind = INVALID_HANDLE_VALUE;
@@ -846,6 +846,7 @@ static size_t tsrm_realpath_r(char *path, size_t start, size_t len, int *ll, tim
 
 #ifdef ZEND_WIN32
 retry_reparse_point:
+		may_retry_reparse_point = 0;
 		if (save) {
 			pathw = php_win32_ioutil_any_to_w(path);
 			if (!pathw) {
@@ -940,6 +941,7 @@ retry_reparse_tag_cloud:
 			CloseHandle(hLink);
 
 			if(pbuffer->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
+				may_retry_reparse_point = 1;
 				reparsetarget = pbuffer->SymbolicLinkReparseBuffer.ReparseTarget;
 				isabsolute = (pbuffer->SymbolicLinkReparseBuffer.Flags == 0) ? 1 : 0;
 #if VIRTUAL_CWD_DEBUG
@@ -1076,7 +1078,7 @@ retry_reparse_tag_cloud:
 			free_alloca(pbuffer, use_heap_large);
 			free(substitutename);
 
-			{
+			if (may_retry_reparse_point) {
 				DWORD attrs;
 
 				FREE_PATHW()