4 files changed, 35 insertions, 1 deletions
diff --git a/base/file_util.h b/base/file_util.h
index 28c96e9..d9f4c3e 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -328,6 +328,9 @@ BASE_API bool NormalizeToNativeFilePath(const FilePath& path,
                                         FilePath* nt_path);
 #endif
 
+// This function will return if the given file is a symlink or not.
+BASE_API bool IsLink(const FilePath& file_path);
+
 // Returns information about the given file path.
 BASE_API bool GetFileInfo(const FilePath& file_path,
                           base::PlatformFileInfo* info);
diff --git a/base/file_util_posix.cc b/base/file_util_posix.cc
index 28d6a61..89487d4 100644
--- a/base/file_util_posix.cc
+++ b/base/file_util_posix.cc
@@ -522,6 +522,21 @@ bool CreateDirectory(const FilePath& full_path) {
   return true;
 }
 
+// TODO(rkc): Refactor GetFileInfo and FileEnumerator to handle symlinks
+// correctly. http://code.google.com/p/chromium-os/issues/detail?id=15948
+bool IsLink(const FilePath& file_path) {
+  struct stat st;
+  // If we can't lstat the file, it's safe to assume that the file won't at
+  // least be a 'followable' link.
+  if (lstat(file_path.value().c_str(), &st) != 0)
+    return false;
+
+  if (S_ISLNK(st.st_mode))
+    return true;
+  else
+    return false;
+}
+
 bool GetFileInfo(const FilePath& file_path, base::PlatformFileInfo* results) {
   stat_wrapper_t file_info;
   if (CallStat(file_path.value().c_str(), &file_info) != 0)
diff --git a/base/file_util_win.cc b/base/file_util_win.cc
index 3689614..93bfe1d 100644
--- a/base/file_util_win.cc
+++ b/base/file_util_win.cc
@@ -702,6 +702,12 @@ bool CreateDirectory(const FilePath& full_path) {
   }
 }
 
+// TODO(rkc): Work out if we want to handle NTFS junctions here or not, handle
+// them if we do decide to.
+bool IsLink(const FilePath& file_path) {
+  return false;
+}
+
 bool GetFileInfo(const FilePath& file_path, base::PlatformFileInfo* results) {
   base::ThreadRestrictions::AssertIOAllowed();
 
diff --git a/webkit/fileapi/file_system_file_util.cc b/webkit/fileapi/file_system_file_util.cc
index 3dfe459..5e5e973 100644
--- a/webkit/fileapi/file_system_file_util.cc
+++ b/webkit/fileapi/file_system_file_util.cc
@@ -95,6 +95,11 @@ PlatformFileError FileSystemFileUtil::GetFileInfo(
     FilePath* platform_file_path) {
   if (!file_util::PathExists(file_path))
     return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+  // TODO(rkc): Fix this hack once we have refactored file_util to handle
+  // symlinks correctly.
+  // http://code.google.com/p/chromium-os/issues/detail?id=15948
+  if (file_util::IsLink(file_path))
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
   if (!file_util::GetFileInfo(file_path, file_info))
     return base::PLATFORM_FILE_ERROR_FAILED;
   *platform_file_path = file_path;
@@ -122,7 +127,12 @@ PlatformFileError FileSystemFileUtil::ReadDirectory(
     // This will just give the entry's name instead of entire path
     // if we use current.value().
     entry.name = file_util::FileEnumerator::GetFilename(info).value();
-    entries->push_back(entry);
+    // TODO(rkc): Fix this also once we've refactored file_util
+    // http://code.google.com/p/chromium-os/issues/detail?id=15948
+    // This currently just prevents a file from showing up at all
+    // if it's a link, hence preventing arbitary 'read' exploits.
+    if (!file_util::IsLink(file_path.Append(entry.name)))
+      entries->push_back(entry);
   }
   return base::PLATFORM_FILE_OK;
 }