Update write checks for external extension file on mac.

base/file_util_posix.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/file_util.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fnmatch.h>
@@ skipping 20 matching lines @@
 #endif
 
 #include <fstream>
 
 #include "base/basictypes.h"
 #include "base/eintr_wrapper.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
+#include "base/stl_util.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/sys_string_conversions.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 
 #if defined(OS_ANDROID)
 #include "base/os_compat_android.h"
 #endif
@@ skipping 33 matching lines @@
   if (!realpath(path.value().c_str(), buf))
     return false;
 
   *real_path = FilePath(buf);
   return true;
 }
 
 // Helper for VerifyPathControlledByUser.
 bool VerifySpecificPathControlledByUser(const FilePath& path,
                                         uid_t owner_uid,
-                                        gid_t group_gid) {
+                                        const std::set<gid_t>& group_gids) {
   stat_wrapper_t stat_info;
   if (CallLstat(path.value().c_str(), &stat_info) != 0) {
     PLOG(ERROR) << "Failed to get information on path "
                 << path.value();
     return false;
   }
 
   if (S_ISLNK(stat_info.st_mode)) {
     LOG(ERROR) << "Path " << path.value()
                << " is a symbolic link.";
     return false;
   }
 
   if (stat_info.st_uid != owner_uid) {
     LOG(ERROR) << "Path " << path.value()
                << " is owned by the wrong user.";
     return false;
   }
 
-  if (stat_info.st_gid != group_gid) {
+  if ((stat_info.st_mode & S_IWGRP) &&
+      !ContainsKey(group_gids, stat_info.st_gid)) {
     LOG(ERROR) << "Path " << path.value()
-               << " is owned by the wrong group.";
+               << " is writable by an unprivileged group.";
     return false;
   }
 
   if (stat_info.st_mode & S_IWOTH) {
     LOG(ERROR) << "Path " << path.value()
                << " is writable by any user.";
     return false;
   }
 
   return true;
@@ skipping 856 matching lines @@
   if (HANDLE_EINTR(close(outfile)) < 0)
     result = false;
 
   return result;
 }
 #endif  // defined(OS_MACOSX)
 
 bool VerifyPathControlledByUser(const FilePath& base,
                                 const FilePath& path,
                                 uid_t owner_uid,
-                                gid_t group_gid) {
+                                const std::set<gid_t>& group_gids) {
   if (base != path && !base.IsParent(path)) {
      LOG(ERROR) << "|base| must be a subdirectory of |path|.  base = \""
                 << base.value() << "\", path = \"" << path.value() << "\"";
      return false;
   }
 
   std::vector<FilePath::StringType> base_components;
   std::vector<FilePath::StringType> path_components;
 
   base.GetComponents(&base_components);
   path.GetComponents(&path_components);
 
   std::vector<FilePath::StringType>::const_iterator ib, ip;
   for (ib = base_components.begin(), ip = path_components.begin();
        ib != base_components.end(); ++ib, ++ip) {
     // |base| must be a subpath of |path|, so all components should match.
     // If these CHECKs fail, look at the test that base is a parent of
     // path at the top of this function.
     CHECK(ip != path_components.end());
     CHECK(*ip == *ib);
   }
 
   FilePath current_path = base;
-  if (!VerifySpecificPathControlledByUser(current_path, owner_uid, group_gid))
+  if (!VerifySpecificPathControlledByUser(current_path, owner_uid, group_gids))
     return false;
 
   for (; ip != path_components.end(); ++ip) {
     current_path = current_path.Append(*ip);
-    if (!VerifySpecificPathControlledByUser(current_path, owner_uid, group_gid))
+    if (!VerifySpecificPathControlledByUser(
+            current_path, owner_uid, group_gids))
       return false;
   }
   return true;
 }
 
 #if defined(OS_MACOSX)
 bool VerifyPathControlledByAdmin(const FilePath& path) {
   const unsigned kRootUid = 0;
   const FilePath kFileSystemRoot("/");
 
   // The name of the administrator group on mac os.
-  const char kAdminGroupName[] = "admin";
+  const char* const kAdminGroupNames[] = {
+    "admin",
+    "wheel"
+  };
 
   // Reading the groups database may touch the file system.
   base::ThreadRestrictions::AssertIOAllowed();
 
-  struct group *group_record = getgrnam(kAdminGroupName);
-  if (!group_record) {
-    PLOG(ERROR) << "Could not get the group ID of group \""
-                << kAdminGroupName << "\".";
-    return false;
+  std::set<gid_t> allowed_group_ids;
+  for (int i = 0, ie = arraysize(kAdminGroupNames); i < ie; ++i) {
+    struct group *group_record = getgrnam(kAdminGroupNames[i]);
+    if (!group_record) {
+      PLOG(ERROR) << "Could not get the group ID of group \""
+                  << kAdminGroupNames[i] << "\".";
+      continue;
+    }
+
+    allowed_group_ids.insert(group_record->gr_gid);
   }
 
   return VerifyPathControlledByUser(
-      kFileSystemRoot, path, kRootUid, group_record->gr_gid);
+      kFileSystemRoot, path, kRootUid, allowed_group_ids);
 }
 #endif  // defined(OS_MACOSX)
 
 }  // namespace file_util