From 27f895cf2c066e49d5724a0c55f9f333d0963501 Mon Sep 17 00:00:00 2001
From: Poorna Krishnamoorthy <poornas@users.noreply.github.com>
Date: Thu, 26 Aug 2021 19:23:12 -0400
Subject: [PATCH] Check pathlength before reading metadata (#13080)

fixes bug where the server returns 503 instead of 400 if
objectName is longer than 255 characters

Fixes regression introduced in #12942
---
 cmd/xl-storage.go      |  4 ++++
 cmd/xl-storage_test.go | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/cmd/xl-storage.go b/cmd/xl-storage.go
index 0b72f2763..6e5391419 100644
--- a/cmd/xl-storage.go
+++ b/cmd/xl-storage.go
@@ -397,6 +397,10 @@ func (s *xlStorage) Healing() *healingTracker {
 }
 
 func (s *xlStorage) readMetadata(itemPath string) ([]byte, error) {
+	if err := checkPathLength(itemPath); err != nil {
+		return nil, err
+	}
+
 	f, err := OpenFile(itemPath, readMode, 0)
 	if err != nil {
 		return nil, err
diff --git a/cmd/xl-storage_test.go b/cmd/xl-storage_test.go
index 8bdb1880b..b14c3add2 100644
--- a/cmd/xl-storage_test.go
+++ b/cmd/xl-storage_test.go
@@ -1818,3 +1818,23 @@ func TestXLStorageVerifyFile(t *testing.T) {
 		t.Fatal("expected to fail bitrot check")
 	}
 }
+
+// TestXLStorageReadMetadata tests readMetadata
+func TestXLStorageReadMetadata(t *testing.T) {
+	volume, object := "test-vol", "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+	tmpDir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	disk, err := newLocalXLStorage(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	disk.MakeVol(context.Background(), volume)
+	if _, err := disk.readMetadata(pathJoin(tmpDir, volume, object)); err != errFileNameTooLong {
+		t.Fatalf("Unexpected error from readMetadata - expect %v: got %v", errFileNameTooLong, err)
+	}
+}