Add check for max symlink count

1 files changed, 15 insertions, 8 deletions

diff --git a/kernel/src/filesystem/vfs.cpp b/kernel/src/filesystem/vfs.cpp
index 03921df..e6d9241 100644
--- a/kernel/src/filesystem/vfs.cpp
+++ b/kernel/src/filesystem/vfs.cpp
@@ -1,5 +1,6 @@
 #include <kernel/filesystem/vfs.hpp>
 
+#include <kernel/filesystem/constants.hpp>
 #include <kernel/filesystem/dentry.hpp>
 #include <kernel/filesystem/devfs/filesystem.hpp>
 #include <kernel/filesystem/filesystem.hpp>
@@ -93,7 +94,7 @@ namespace kernel::filesystem
 
   auto vfs::do_mount(std::string_view source, std::string_view target) -> operation_result
   {
-    if (!kernel::filesystem::path::is_valid_path(source) || !kernel::filesystem::path::is_valid_path(target))
+    if (!path::is_valid_path(source) || !path::is_valid_path(target))
     {
       return operation_result::invalid_path;
     }
@@ -116,7 +117,7 @@ namespace kernel::filesystem
 
   auto vfs::unmount(std::string_view path) -> operation_result
   {
-    if (!kernel::filesystem::path::is_valid_path(path))
+    if (!path::is_valid_path(path))
     {
       return operation_result::invalid_path;
     }
@@ -147,7 +148,7 @@ namespace kernel::filesystem
 
   auto vfs::resolve_path(std::string_view path) -> kstd::shared_ptr<dentry>
   {
-    if (!kernel::filesystem::path::is_valid_absolute_path(path))
+    if (!path::is_valid_absolute_path(path))
     {
       return nullptr;
     }
@@ -161,10 +162,12 @@ namespace kernel::filesystem
 
     auto current_dentry = current_mount->root_dentry();
 
-    auto path_parts = kernel::filesystem::path::split(path);
+    auto path_parts = path::split(path);
     kstd::vector path_parts_vector(path_parts.begin(), path_parts.end());
     std::ranges::reverse(path_parts_vector);
 
+    auto symlink_counter = 0uz;
+
     while (!path_parts_vector.empty())
     {
       auto part = path_parts_vector.back();
@@ -230,18 +233,22 @@ namespace kernel::filesystem
 
       if (next_dentry->get_inode()->is_symbolic_link())
       {
-        // TODO BA-FS26 max symbolic link depth to prevent infinite loops
-        kstd::vector<uint8_t> buffer(4096);  // TODO BA-FS26 max symlink size?
+        if (symlink_counter++ > constants::symloop_max)
+        {
+          return nullptr;
+        }
+
+        kstd::vector<uint8_t> buffer(constants::symlink_max_path_length);
         auto const bytes_read = next_dentry->get_inode()->read(buffer.data(), 0, buffer.size());
         auto const symbolic_link_path = std::string_view{reinterpret_cast<char const *>(buffer.data()), bytes_read};
 
-        auto symbolic_link_parts = kernel::filesystem::path::split(symbolic_link_path);
+        auto symbolic_link_parts = path::split(symbolic_link_path);
         kstd::vector symbolic_link_parts_vector(symbolic_link_parts.begin(), symbolic_link_parts.end());
         std::ranges::reverse(symbolic_link_parts_vector);
 
         path_parts_vector.insert_range(path_parts_vector.end(), symbolic_link_parts_vector);
 
-        if (kernel::filesystem::path::is_valid_absolute_path(symbolic_link_path))
+        if (path::is_valid_absolute_path(symbolic_link_path))
         {
           current_mount = m_mount_table.find_longest_prefix_mount("/");
           current_dentry = current_mount->root_dentry();