From ddf601c6ecdfea401996ed14ffbfcf40d0e3628e Mon Sep 17 00:00:00 2001
From: chaoticgd <43898262+chaoticgd@users.noreply.github.com>
Date: Sun, 1 Dec 2024 23:40:58 +0000
Subject: [PATCH] FileSystem: Don't follow symlinks when recursively deleting
 directories

---
 common/FileSystem.cpp | 98 +++++++++++++++++++++++++++++++------------
 common/FileSystem.h   |  7 +++-
 2 files changed, 78 insertions(+), 27 deletions(-)

diff --git a/common/FileSystem.cpp b/common/FileSystem.cpp
index 826aee13ba8b9..10d587f30b717 100644
--- a/common/FileSystem.cpp
+++ b/common/FileSystem.cpp
@@ -1225,7 +1225,12 @@ bool FileSystem::RecursiveDeleteDirectory(const char* path)
 	{
 		for (const FILESYSTEM_FIND_DATA& fd : results)
 		{
-			if (fd.Attributes & FILESYSTEM_FILE_ATTRIBUTE_DIRECTORY)
+			if (IsSymbolicLink(fd.FileName.c_str()))
+			{
+				if (!DeleteSymbolicLink(fd.FileName.c_str()))
+					return false;
+			}
+			else if ((fd.Attributes & FILESYSTEM_FILE_ATTRIBUTE_DIRECTORY))
 			{
 				if (!RecursiveDeleteDirectory(fd.FileName.c_str()))
 					return false;
@@ -1650,21 +1655,6 @@ bool FileSystem::DirectoryExists(const char* path)
 		return false;
 }
 
-bool FileSystem::IsRealDirectory(const char* path)
-{
-	// convert to wide string
-	const std::wstring wpath = GetWin32Path(path);
-	if (wpath.empty())
-		return false;
-
-	// determine attributes for the path. if it's a directory, things have to be handled differently..
-	const DWORD fileAttributes = GetFileAttributesW(wpath.c_str());
-	if (fileAttributes == INVALID_FILE_ATTRIBUTES)
-		return false;
-
-	return ((fileAttributes & (FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_REPARSE_POINT)) != FILE_ATTRIBUTE_DIRECTORY);
-}
-
 bool FileSystem::DirectoryIsEmpty(const char* path)
 {
 	std::wstring wpath = GetWin32Path(path);
@@ -1935,6 +1925,52 @@ bool FileSystem::SetPathCompression(const char* path, bool enable)
 	return result;
 }
 
+bool FileSystem::IsSymbolicLink(const char* path)
+{
+	// convert to wide string
+	const std::wstring wpath = GetWin32Path(path);
+	if (wpath.empty())
+		return false;
+
+	// determine attributes for the path
+	const DWORD fileAttributes = GetFileAttributesW(wpath.c_str());
+	if (fileAttributes == INVALID_FILE_ATTRIBUTES)
+		return false;
+
+	return fileAttributes & FILE_ATTRIBUTE_REPARSE_POINT;
+}
+
+bool FileSystem::DeleteSymbolicLink(const char* path, Error* error)
+{
+	// convert to wide string
+	const std::wstring wpath = GetWin32Path(path);
+	if (wpath.empty())
+	{
+		Error::SetStringView(error, "Invalid path.");
+		return false;
+	}
+
+	// delete the symbolic link
+	if (DirectoryExists(path))
+	{
+		if (!RemoveDirectoryW(wpath.c_str()))
+		{
+			Error::SetWin32(error, "RemoveDirectoryW() failed: ", GetLastError());
+			return false;
+		}
+	}
+	else
+	{
+		if (!DeleteFileW(wpath.c_str()))
+		{
+			Error::SetWin32(error, "DeleteFileW() failed: ", GetLastError());
+			return false;
+		}
+	}
+
+	return true;
+}
+
 #else
 
 // No 32-bit file offsets breaking stuff please.
@@ -2216,15 +2252,6 @@ bool FileSystem::DirectoryExists(const char* path)
 		return false;
 }
 
-bool FileSystem::IsRealDirectory(const char* path)
-{
-	struct stat sysStatData;
-	if (lstat(path, &sysStatData) < 0)
-		return false;
-
-	return (S_ISDIR(sysStatData.st_mode) && !S_ISLNK(sysStatData.st_mode));
-}
-
 bool FileSystem::DirectoryIsEmpty(const char* path)
 {
 	DIR* pDir = opendir(path);
@@ -2350,7 +2377,6 @@ bool FileSystem::DeleteFilePath(const char* path, Error* error)
 
 	return true;
 }
-
 bool FileSystem::RenamePath(const char* old_path, const char* new_path, Error* error)
 {
 	if (old_path[0] == '\0' || new_path[0] == '\0')
@@ -2478,6 +2504,26 @@ bool FileSystem::SetPathCompression(const char* path, bool enable)
 	return false;
 }
 
+bool FileSystem::IsSymbolicLink(const char* path)
+{
+	struct stat sysStatData;
+	if (lstat(path, &sysStatData) < 0)
+		return false;
+
+	return S_ISLNK(sysStatData.st_mode);
+}
+
+bool FileSystem::DeleteSymbolicLink(const char* path, Error* error)
+{
+	if (unlink(path) != 0)
+	{
+		Error::SetErrno(error, "unlink() failed: ", errno);
+		return false;
+	}
+
+	return true;
+}
+
 FileSystem::POSIXLock::POSIXLock(int fd)
 {
 	if (lockf(fd, F_LOCK, 0) == 0)
diff --git a/common/FileSystem.h b/common/FileSystem.h
index a9bdee5a3bff8..e1f73229dbcac 100644
--- a/common/FileSystem.h
+++ b/common/FileSystem.h
@@ -84,7 +84,6 @@ namespace FileSystem
 
 	/// Directory exists?
 	bool DirectoryExists(const char* path);
-	bool IsRealDirectory(const char* path);
 
 	/// Directory does not contain any files?
 	bool DirectoryIsEmpty(const char* path);
@@ -170,6 +169,12 @@ namespace FileSystem
 	/// Does nothing and returns false on non-Windows platforms.
 	bool SetPathCompression(const char* path, bool enable);
 
+	/// Checks if a file or directory is a symbolic link.
+	bool IsSymbolicLink(const char* path);
+
+	/// Deletes a symbolic link (either a file or directory).
+	bool DeleteSymbolicLink(const char* path, Error* error = nullptr);
+
 #ifdef _WIN32
 	// Path limit remover, but also converts to a wide string at the same time.
 	bool GetWin32Path(std::wstring* dest, std::string_view str);