diff --git a/frameworks/native/backup_ext/src/untar_file.cpp b/frameworks/native/backup_ext/src/untar_file.cpp
index 52c9964d3fda02fcd318f710a181a43e441c1882..bf367c10be78ec8dc59171640462c40a55ec76a5 100644
--- a/frameworks/native/backup_ext/src/untar_file.cpp
+++ b/frameworks/native/backup_ext/src/untar_file.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023 Huawei Device Co., Ltd.
+ * Copyright (c) 2023-2024 Huawei Device Co., Ltd.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -178,8 +178,9 @@ int UntarFile::ParseTarFile(const string &rootPath)
             HILOGE("Parsing tar file completed, read data count is less then block size.");
             return 0;
         }
+        TarHeader *header = reinterpret_cast<TarHeader *>(buff);
         // two empty continuous block indicate end of file
-        if (IsEmptyBlock(buff)) {
+        if (IsEmptyBlock(buff) && header->typeFlag != GNUTYPE_LONGNAME) {
             char tailBuff[BLOCK_SIZE] = {0};
             size_t tailRead = fread(tailBuff, 1, BLOCK_SIZE, tarFilePtr_);
             if (tailRead == BLOCK_SIZE && IsEmptyBlock(tailBuff)) {
@@ -188,7 +189,6 @@ int UntarFile::ParseTarFile(const string &rootPath)
             }
         }
         // check header
-        TarHeader *header = reinterpret_cast<TarHeader *>(buff);
         if (!IsValidTarBlock(*header)) {
             // when split unpack, ftell size is over than file really size [0,READ_BUFF_SIZE]
             if (ftello(tarFilePtr_) > (tarFileSize_ + READ_BUFF_SIZE) || !IsEmptyBlock(buff)) {
@@ -442,6 +442,9 @@ string UntarFile::GenRealPath(const string &rootPath, const string &realName)
         realPath = realPath.substr(0, len - 1);
     }
     realPath.append((realName[0] == '/') ? realName : ("/" + realName));
+    if (realPath[0] == '/') {
+        realPath = realPath.substr(1, realPath.length());
+    }
     return realPath;
 }
 
diff --git a/tests/unittests/backup_ext/untar_file_test.cpp b/tests/unittests/backup_ext/untar_file_test.cpp
index bc9dc946243a4e6be9060506b70af9a3e3131742..60df5d74ccdf5ef7804c6b6e231e0bf7b32fdafe 100644
--- a/tests/unittests/backup_ext/untar_file_test.cpp
+++ b/tests/unittests/backup_ext/untar_file_test.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022-2023 Huawei Device Co., Ltd.
+ * Copyright (c) 2022-2024 Huawei Device Co., Ltd.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -220,4 +220,55 @@ HWTEST_F(UntarFileTest, SUB_Untar_File_UnPacket_0400, testing::ext::TestSize.Lev
     }
     GTEST_LOG_(INFO) << "UntarFileTest-end SUB_Untar_File_UnPacket_0400";
 }
+
+/**
+ * @tc.number: SUB_Untar_File_UnPacket_0500
+ * @tc.name: SUB_Untar_File_UnPacket_0500
+ * @tc.desc: 测试 UnPacket 接口
+ * @tc.size: MEDIUM
+ * @tc.type: FUNC
+ * @tc.level Level 1
+ * @tc.require: I6F3GV
+ */
+HWTEST_F(UntarFileTest, SUB_Untar_File_UnPacket_0500, testing::ext::TestSize.Level1)
+{
+    GTEST_LOG_(INFO) << "UntarFileTest-begin SUB_Untar_File_UnPacket_0500";
+    try {
+        // 预置文件和目录
+        TestManager tm("SUB_Untar_File_UnPacket_0500");
+        string root = tm.GetRootDirCurTest();
+        string testDir = root + "/testdir/";
+        if (mkdir(testDir.data(), S_IRWXU) && errno != EEXIST) {
+            GTEST_LOG_(INFO) << " invoked mkdir failure, errno :" << errno;
+            throw BError(errno);
+        }
+        string aFile = testDir;
+        string bFile = testDir;
+        // 循环100次，用来构造超长路径和超长文件名
+        for (int i = 0; i < 100; i++) {
+            aFile += "test001/test002/test003/test004/test005/";
+            bFile += "ab";
+        }
+        aFile += "a.txt";
+        bFile += ".txt";
+        SaveStringToFile(aFile, "hello");
+        SaveStringToFile(bFile, "world");
+
+        string tarFile = root + "/test.0.tar";
+        TarMap tarMap {};
+        vector<string> smallFiles;
+        smallFiles.emplace_back(aFile);
+        smallFiles.emplace_back(bFile);
+        TarFile::GetInstance().Packet(smallFiles, "test", root, tarMap);
+
+        string rootPath(root);
+        int ret = UntarFile::GetInstance().UnPacket(tarFile, rootPath);
+        EXPECT_EQ(ret, 0);
+        ClearCache();
+    } catch (...) {
+        EXPECT_TRUE(false);
+        GTEST_LOG_(INFO) << "UntarFileTest-an exception occurred by UntarFile.";
+    }
+    GTEST_LOG_(INFO) << "UntarFileTest-end SUB_Untar_File_UnPacket_0500";
+}
 } // namespace OHOS::FileManagement::Backup
\ No newline at end of file
diff --git a/utils/src/b_filesystem/b_dir.cpp b/utils/src/b_filesystem/b_dir.cpp
index 3f02020cd43bd93a6b9bd850f3d243cc5a287fa5..618bcbb7c53f854c86a817aa18d62e51a0ff2861 100644
--- a/utils/src/b_filesystem/b_dir.cpp
+++ b/utils/src/b_filesystem/b_dir.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022-2023 Huawei Device Co., Ltd.
+ * Copyright (c) 2022-2024 Huawei Device Co., Ltd.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -34,6 +34,7 @@
 
 namespace OHOS::FileManagement::Backup {
 using namespace std;
+const int32_t PATH_MAX_LEN = 4096;
 
 static bool IsEmptyDirectory(const string &path)
 {
@@ -72,6 +73,17 @@ static tuple<ErrCode, map<string, struct stat>, vector<string>> GetFile(const st
     return {BError(BError::Codes::OK).GetCode(), files, smallFiles};
 }
 
+static uint32_t CheckOverLongPath(const string &path)
+{
+    uint32_t len = path.length();
+    if (len >= PATH_MAX_LEN) {
+        size_t found = path.find_last_of('/');
+        string sub = path.substr(found + 1);
+        HILOGE("Path over long, length:%{public}d, fileName:%{public}s.", len, sub.c_str());
+    }
+    return len;
+}
+
 static tuple<ErrCode, map<string, struct stat>, vector<string>> GetDirFilesDetail(const string &path,
                                                                                   bool recursion,
                                                                                   off_t size = -1)
@@ -114,7 +126,7 @@ static tuple<ErrCode, map<string, struct stat>, vector<string>> GetDirFilesDetai
         } else {
             struct stat sta = {};
             string fileName = IncludeTrailingPathDelimiter(path) + string(ptr->d_name);
-            if (stat(fileName.data(), &sta) == -1) {
+            if (CheckOverLongPath(fileName) >= PATH_MAX_LEN || stat(fileName.data(), &sta) == -1) {
                 continue;
             }
             if (sta.st_size <= size) {