fix: Safely handle filesystem exception

src/backend_model.cc

@@ -363,9 +363,12 @@ TritonModel::GetBackendLibraryProperties(
                                        model_config->name() +
                                        "', searched: " + search_paths_str);
   }
-  if (IsChildPathEscapingParentPath(
-          *backend_libpath /* child_path */,
-          *backend_libdir /* parent_path */)) {
+
+  bool is_escaped = false;
+  RETURN_IF_ERROR(IsChildPathEscapingParentPath(
+      *backend_libpath /* child_path */, *backend_libdir /* parent_path */,
+      &is_escaped));
+  if (is_escaped) {
     return Status(
         Status::Code::INVALID_ARG,
         "backend library name '" + cpp_backend_libname +

src/filesystem/api.cc

@@ -1,4 +1,4 @@
-// Copyright 2019-2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// Copyright 2019-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
@@ -399,17 +399,33 @@ IsAbsolutePath(const std::string& path)
   return !path.empty() && (path[0] == '/');
 }
 
-bool
+Status
 IsChildPathEscapingParentPath(
-    const std::string& child_path, const std::string& parent_path)
-{
-  const std::string absolute_child_path =
-      std::filesystem::weakly_canonical(child_path).string();
-  const std::string absolute_parent_path =
-      std::filesystem::canonical(parent_path).string();
+    const std::string& child_path, const std::string& parent_path,
+    bool* is_escaped)
+{
+  std::string absolute_child_path;
+  std::string absolute_parent_path;
+  try {
+    absolute_child_path =
+        std::filesystem::weakly_canonical(child_path).string();
+  }
+  catch (const std::exception& e) {
+    return Status(
+        Status::Code::INVALID_ARG,
+        "Invalid path '" + child_path + "': " + e.what());
+  }
+  try {
+    absolute_parent_path = std::filesystem::canonical(parent_path).string();
+  }
+  catch (const std::exception& e) {
+    return Status(
+        Status::Code::INVALID_ARG,
+        "Nonexistent path '" + parent_path + "': " + e.what());
+  }
   // Can use starts_with() over rfind() in C++20.
-  bool is_escape = absolute_child_path.rfind(absolute_parent_path, 0) != 0;
-  return is_escape;
+  *is_escaped = absolute_child_path.rfind(absolute_parent_path, 0) != 0;
+  return Status::Success;
 }
 
 std::string

src/filesystem/api.h

@@ -1,4 +1,4 @@
-// Copyright 2019-2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// Copyright 2019-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
@@ -131,10 +131,12 @@ bool IsAbsolutePath(const std::string& path);
 /// Check if the child path escapes from its parent path.
 /// \param child_path The child path.
 /// \param parent_path The parent path. The path must exist.
-/// \return true if the child path escapes from its parent path, false if the
-/// child path is within its parent path.
-bool IsChildPathEscapingParentPath(
-    const std::string& child_path, const std::string& parent_path);
+/// \param is_escaped returns true if the child path escapes from its parent
+/// path, false if the child path is within its parent path. \return Error
+/// status
+Status IsChildPathEscapingParentPath(
+    const std::string& child_path, const std::string& parent_path,
+    bool* is_escaped);
 
 /// Join path segments into a longer path
 /// \param segments The path segments.

src/model.cc

@@ -115,7 +115,10 @@ Model::Init(const bool is_config_provided)
 
     if (!io.label_filename().empty()) {
       auto label_path = JoinPath({model_dir_, io.label_filename()});
-      if (IsChildPathEscapingParentPath(label_path, model_dir_)) {
+      bool is_escaped = false;
+      RETURN_IF_ERROR(
+          IsChildPathEscapingParentPath(label_path, model_dir_, &is_escaped));
+      if (is_escaped) {
         return Status(
             Status::Code::UNSUPPORTED,
             "label file path '" + label_path + "' for output '" + io.name() +

src/model_repository_manager/model_repository_manager.cc

@@ -107,8 +107,16 @@ class LocalizeRepoAgent : public TritonRepoAgent {
           RETURN_TRITONSERVER_ERROR_IF_ERROR(
               agent_model->AcquireMutableLocation(
                   TRITONREPOAGENT_ARTIFACT_FILESYSTEM, &temp_dir_cstr));
-          const std::string temp_dir =
-              std::filesystem::canonical(temp_dir_cstr).string();
+          std::string temp_dir;
+          try {
+            temp_dir = std::filesystem::canonical(temp_dir_cstr).string();
+          }
+          catch (const std::exception& e) {
+            const std::string err_msg = std::string("Nonexistent path '") +
+                                        temp_dir_cstr + "': " + e.what();
+            return TRITONSERVER_ErrorNew(
+                TRITONSERVER_ERROR_INTERNAL, err_msg.c_str());
+          }
           const auto& files =
               *reinterpret_cast<std::vector<const InferenceParameter*>*>(
                   agent_model->State());
@@ -136,20 +144,31 @@ class LocalizeRepoAgent : public TritonRepoAgent {
                         .c_str());
               }
 
+              const std::string file_relpath =
+                  file->Name().substr(file_prefix.size());
+              std::string file_path;
+              try {
+                file_path = std::filesystem::weakly_canonical(
+                                JoinPath({temp_dir, file_relpath}))
+                                .string();
+              }
+              catch (const std::exception& e) {
+                const std::string err_msg =
+                    std::string("Invalid file parameter '") + file_relpath +
+                    "': " + e.what();
+                return TRITONSERVER_ErrorNew(
+                    TRITONSERVER_ERROR_INVALID_ARG, err_msg.c_str());
+              }
+
               // Resolve any relative paths or symlinks, and enforce that target
               // directory stays within model directory for security.
-              const std::string file_path =
-                  std::filesystem::weakly_canonical(
-                      JoinPath(
-                          {temp_dir, file->Name().substr(file_prefix.size())}))
-                      .string();
               if (file_path.rfind(temp_dir, 0) != 0) {
+                const std::string msg =
+                    std::string("Invalid file parameter '") + file->Name() +
+                    "' with normalized path '" + file_path +
+                    "' must stay within model directory.";
                 return TRITONSERVER_ErrorNew(
-                    TRITONSERVER_ERROR_INVALID_ARG,
-                    (std::string("Invalid file parameter '") + file->Name() +
-                     "' with normalized path '" + file_path +
-                     "' must stay within model directory.")
-                        .c_str());
+                    TRITONSERVER_ERROR_INVALID_ARG, msg.c_str());
               }
 
               // Save model override file to the instructed directory using the