diff --git a/src/logservice/palf/log_engine.cpp b/src/logservice/palf/log_engine.cpp
index bc9c8a9132b46a3f3e83843c627171e6e9fd7fde..5e32547422ac8ede53daa9c5424441025fa3c9ec 100644
--- a/src/logservice/palf/log_engine.cpp
+++ b/src/logservice/palf/log_engine.cpp
@@ -547,6 +547,9 @@ int LogEngine::read_group_entry_header(const LSN &lsn, LogGroupEntryHeader &log_
     ret = OB_NOT_INIT;
   } else if (false == lsn.is_valid()) {
     ret = OB_INVALID_ARGUMENT;
+  } else if (!read_buf.is_valid()) {
+    ret = OB_ALLOCATE_MEMORY_FAILED;
+    PALF_LOG(WARN, "allocate memory failed", KPC(this), K(lsn));
   } else if (OB_FAIL(log_storage_.pread_without_block_header(lsn, in_read_size, read_buf, out_read_size))) {
     PALF_LOG(WARN, "LogStorage pread failed", K(ret));
   } else if (OB_FAIL(log_group_entry_header.deserialize(read_buf.buf_, in_read_size, pos))) {
@@ -1150,6 +1153,9 @@ int LogEngine::construct_log_meta_(const LSN &lsn, block_id_t &expected_next_blo
   LogMetaEntry meta_entry;
   if (false == lsn.is_valid()) {
     PALF_LOG(INFO, "there is no meta entry, maybe create palf failed", K(ret), K_(palf_id), K_(is_inited));
+  } else if (!read_buf.is_valid()) {
+    ret = OB_ALLOCATE_MEMORY_FAILED;
+    PALF_LOG(WARN, "allocate memory failed", KPC(this), K(lsn));
   } else if (OB_FAIL(log_meta_storage_.pread(lsn, buf_len, read_buf, out_read_size))) {
     PALF_LOG(WARN, "ObLogMetaStorage pread failed", K(ret), K_(palf_id), K_(is_inited));
     // NB: when lsn is invalid, means there is no data on disk.
diff --git a/src/logservice/palf/log_reader.cpp b/src/logservice/palf/log_reader.cpp
index 53485914fc417b0f1e436f14e2db9b2c55703b00..b41fa5122476c48e360ed39410b5b9932a34d0bd 100644
--- a/src/logservice/palf/log_reader.cpp
+++ b/src/logservice/palf/log_reader.cpp
@@ -113,7 +113,6 @@ int LogReader::inner_pread_(const int read_io_fd,
   offset_t backoff = start_offset - aligned_start_offset;
   int64_t aligned_in_read_size = upper_align(in_read_size + backoff, LOG_DIO_ALIGN_SIZE);
   int64_t limited_and_aligned_in_read_size = 0;
-  ReadBufGuard read_buf_guard("LogReader", aligned_in_read_size);
   if (MAX_LOG_BUFFER_SIZE + LOG_DIO_ALIGN_SIZE < aligned_in_read_size) {
     ret = OB_BUF_NOT_ENOUGH;
     PALF_LOG(ERROR, "aligned_in_read_size is greater than MAX BUFFER LEN",
diff --git a/src/logservice/palf/log_reader_utils.cpp b/src/logservice/palf/log_reader_utils.cpp
index b3100d578815ff3009aaa4833cd58f895e58f5d7..4260e03475392b1c1c83b9b64f1bafa8d549d7de 100644
--- a/src/logservice/palf/log_reader_utils.cpp
+++ b/src/logservice/palf/log_reader_utils.cpp
@@ -30,6 +30,11 @@ ReadBuf::ReadBuf(char *buf, const int64_t buf_len) : buf_(buf), buf_len_(buf_len
 {
 }
 
+ReadBuf::ReadBuf(const ReadBuf &rhs)
+{
+  *this = rhs;
+}
+
 ReadBuf::~ReadBuf()
 {
   reset();
@@ -51,6 +56,12 @@ bool ReadBuf::operator!=(const ReadBuf &rhs) const
   return !operator==(rhs);
 }
 
+ReadBuf &ReadBuf::operator=(const ReadBuf &rhs)
+{
+  buf_ = rhs.buf_;
+  buf_len_ = rhs.buf_len_;
+  return *this;
+}
 
 bool ReadBuf::is_valid() const
 {
diff --git a/src/logservice/palf/log_reader_utils.h b/src/logservice/palf/log_reader_utils.h
index 55a1f561c875858221cc6a0ca03eba47ac3a5cf3..a1c07a82a51f676e8caf0d0beeb60146bc71ee3b 100644
--- a/src/logservice/palf/log_reader_utils.h
+++ b/src/logservice/palf/log_reader_utils.h
@@ -22,8 +22,11 @@ struct ReadBuf
 {
   ReadBuf();
   ReadBuf(char *buf, const int64_t buf_len);
+  ReadBuf(const ReadBuf &rhs);
   bool operator==(const ReadBuf &rhs) const;
   bool operator!=(const ReadBuf &rhs) const;
+
+  ReadBuf &operator=(const ReadBuf &rhs);
   ~ReadBuf();
   void reset();
   bool is_valid() const;
diff --git a/src/logservice/palf/log_storage.cpp b/src/logservice/palf/log_storage.cpp
index 7859de910e96575d0dabf01e3a8d3844919577bc..b11be27c56527eefee1f133e1f69b826fa19169c 100644
--- a/src/logservice/palf/log_storage.cpp
+++ b/src/logservice/palf/log_storage.cpp
@@ -733,7 +733,10 @@ int LogStorage::read_block_header_(const block_id_t block_id,
   LSN log_tail = get_readable_log_tail_guarded_by_lock_();
   block_id_t max_block_id = lsn_2_block(log_tail, logical_block_size_);
   bool last_block_has_data = (0 == lsn_2_offset(log_tail, logical_block_size_) ? false : true);
-  if (block_id > max_block_id || (block_id == max_block_id && false == last_block_has_data)) {
+  if (!read_buf.is_valid()) {
+    ret = OB_ALLOCATE_MEMORY_FAILED;
+    PALF_LOG(WARN, "allocate memory failed");
+  } else if (block_id > max_block_id || (block_id == max_block_id && false == last_block_has_data)) {
     ret = OB_ERR_OUT_OF_UPPER_BOUND;
     PALF_LOG(WARN, "block_id is large than max_block_id", K(ret), K(block_id),
              K(log_tail), K(max_block_id), K(log_block_header));
diff --git a/src/logservice/palf/palf_handle_impl.cpp b/src/logservice/palf/palf_handle_impl.cpp
index 990696248fcf4158b253c43e12371cbf87b5723f..fe21cf04bf3704fda641a57e9450ba79b30108d0 100644
--- a/src/logservice/palf/palf_handle_impl.cpp
+++ b/src/logservice/palf/palf_handle_impl.cpp
@@ -3943,10 +3943,13 @@ int PalfHandleImpl::read_and_append_log_group_entry_before_ts_(
   };
 
   last_log_buf = NULL;
-  if (OB_FAIL(iterator.init(start_lsn, get_file_end_lsn, log_engine_.get_log_storage()))) {
+  ReadBufGuard read_buf_guard("Palf", MAX_LOG_BUFFER_SIZE);
+  if (!read_buf_guard.read_buf_.is_valid()) {
+    ret = OB_ALLOCATE_MEMORY_FAILED;
+    PALF_LOG(WARN, "allocate memory failed", KPC(this));
+  } else if (OB_FAIL(iterator.init(start_lsn, get_file_end_lsn, log_engine_.get_log_storage()))) {
     PALF_LOG(WARN, "iterator init failed", K(ret), KPC(this), K(start_lsn), K(flashback_scn));
   } else {
-    ReadBufGuard read_buf_guard("Palf", MAX_LOG_BUFFER_SIZE);
     const int64_t read_buf_len = read_buf_guard.read_buf_.buf_len_;
     char *&read_buf = read_buf_guard.read_buf_.buf_;
     const char *buffer = NULL;