diff --git a/HISTORY.md b/HISTORY.md
index 64137894d..f24b33d15 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -15,6 +15,7 @@
 * Fixed a bug that DB flush uses `options.compression` even `options.compression_per_level` is set.
 * Fixed a bug that DisableManualCompaction may assert when disable an unscheduled manual compaction.
 * Fixed a potential timer crash when open close DB concurrently.
+* Fixed a race condition for `alive_log_files_` in non-two-write-queues mode. The race is between the write_thread_ in WriteToWAL() and another thread executing `FindObsoleteFiles()`. The race condition will be caught if `__glibcxx_requires_nonempty` is enabled.
 
 ### Public API changes
 * Remove BlockBasedTableOptions.hash_index_allow_collision which already takes no effect.
diff --git a/db/db_impl/db_impl.h b/db/db_impl/db_impl.h
index 8e4b9d048..320c07463 100644
--- a/db/db_impl/db_impl.h
+++ b/db/db_impl/db_impl.h
@@ -1789,7 +1789,8 @@ class DBImpl : public DB {
   // associated with this WriteToWAL
   IOStatus WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer,
                       uint64_t* log_used, uint64_t* log_size,
-                      Env::IOPriority rate_limiter_priority);
+                      Env::IOPriority rate_limiter_priority,
+                      bool with_db_mutex = false, bool with_log_mutex = false);
 
   IOStatus WriteToWAL(const WriteThread::WriteGroup& write_group,
                       log::Writer* log_writer, uint64_t* log_used,
@@ -2115,12 +2116,15 @@ class DBImpl : public DB {
   bool persistent_stats_cfd_exists_ = true;
 
   // Without two_write_queues, read and writes to alive_log_files_ are
-  // protected by mutex_. However since back() is never popped, and push_back()
-  // is done only from write_thread_, the same thread can access the item
-  // reffered by back() without mutex_. With two_write_queues_, writes
+  // protected by mutex_. With two_write_queues_, writes
   // are protected by locking both mutex_ and log_write_mutex_, and reads must
   // be under either mutex_ or log_write_mutex_.
   std::deque<LogFileNumberSize> alive_log_files_;
+  // Caching the result of `alive_log_files_.back()` so that we do not have to
+  // call `alive_log_files_.back()` in the write thread (WriteToWAL()) which
+  // requires locking db mutex if log_mutex_ is not already held in
+  // two-write-queues mode.
+  std::deque<LogFileNumberSize>::reverse_iterator alive_log_files_tail_;
   // Log files that aren't fully synced, and the current log file.
   // Synchronization:
   //  - push_back() is done from write_thread_ with locked mutex_ and
diff --git a/db/db_impl/db_impl_open.cc b/db/db_impl/db_impl_open.cc
index 101da5fa1..94ad8bf85 100644
--- a/db/db_impl/db_impl_open.cc
+++ b/db/db_impl/db_impl_open.cc
@@ -1364,6 +1364,7 @@ Status DBImpl::RestoreAliveLogFiles(const std::vector<uint64_t>& wal_numbers) {
     total_log_size_ += log.size;
     alive_log_files_.push_back(log);
   }
+  alive_log_files_tail_ = alive_log_files_.rbegin();
   if (two_write_queues_) {
     log_write_mutex_.Unlock();
   }
@@ -1775,6 +1776,7 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
       }
       impl->alive_log_files_.push_back(
           DBImpl::LogFileNumberSize(impl->logfile_number_));
+      impl->alive_log_files_tail_ = impl->alive_log_files_.rbegin();
       if (impl->two_write_queues_) {
         impl->log_write_mutex_.Unlock();
       }
@@ -1796,7 +1798,7 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
         uint64_t log_used, log_size;
         log::Writer* log_writer = impl->logs_.back().writer;
         s = impl->WriteToWAL(empty_batch, log_writer, &log_used, &log_size,
-                             Env::IO_TOTAL);
+                             Env::IO_TOTAL, /*with_db_mutex==*/true);
         if (s.ok()) {
           // Need to fsync, otherwise it might get lost after a power reset.
           s = impl->FlushWAL(false);
diff --git a/db/db_impl/db_impl_write.cc b/db/db_impl/db_impl_write.cc
index bb9eae90f..f8200a26e 100644
--- a/db/db_impl/db_impl_write.cc
+++ b/db/db_impl/db_impl_write.cc
@@ -1171,8 +1171,22 @@ WriteBatch* DBImpl::MergeBatch(const WriteThread::WriteGroup& write_group,
 IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
                             log::Writer* log_writer, uint64_t* log_used,
                             uint64_t* log_size,
-                            Env::IOPriority rate_limiter_priority) {
+                            Env::IOPriority rate_limiter_priority,
+                            bool with_db_mutex, bool with_log_mutex) {
   assert(log_size != nullptr);
+
+  // Assert mutex explicitly.
+  if (with_db_mutex) {
+    mutex_.AssertHeld();
+  } else if (two_write_queues_) {
+    log_write_mutex_.AssertHeld();
+    assert(with_log_mutex);
+  }
+
+#ifdef NDEBUG
+  (void)with_log_mutex;
+#endif
+
   Slice log_entry = WriteBatchInternal::Contents(&merged_batch);
   *log_size = log_entry.size();
   // When two_write_queues_ WriteToWAL has to be protected from concurretn calls
@@ -1195,9 +1209,20 @@ IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
     *log_used = logfile_number_;
   }
   total_log_size_ += log_entry.size();
-  // TODO(myabandeh): it might be unsafe to access alive_log_files_.back() here
-  // since alive_log_files_ might be modified concurrently
-  alive_log_files_.back().AddSize(log_entry.size());
+#if defined(__has_feature)
+#if __has_feature(thread_sanitizer)
+  if (with_db_mutex || with_log_mutex) {
+#endif  // __has_feature(thread_sanitizer)
+#endif  // defined(__has_feature)
+    assert(alive_log_files_tail_ != alive_log_files_.rend());
+    assert(alive_log_files_tail_ == alive_log_files_.rbegin());
+#if defined(__has_feature)
+#if __has_feature(thread_sanitizer)
+  }
+#endif  // __has_feature(thread_sanitizer)
+#endif  // defined(__has_feature)
+  LogFileNumberSize& last_alive_log = *alive_log_files_tail_;
+  last_alive_log.AddSize(*log_size);
   log_empty_ = false;
   return io_s;
 }
@@ -1207,6 +1232,7 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
                             bool need_log_sync, bool need_log_dir_sync,
                             SequenceNumber sequence) {
   IOStatus io_s;
+  assert(!two_write_queues_);
   assert(!write_group.leader->disable_wal);
   // Same holds for all in the batch group
   size_t write_with_wal = 0;
@@ -1295,6 +1321,7 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
     SequenceNumber* last_sequence, size_t seq_inc) {
   IOStatus io_s;
 
+  assert(two_write_queues_ || immutable_db_options_.unordered_write);
   assert(!write_group.leader->disable_wal);
   // Same holds for all in the batch group
   WriteBatch tmp_batch;
@@ -1320,7 +1347,8 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
   log::Writer* log_writer = logs_.back().writer;
   uint64_t log_size;
   io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size,
-                    write_group.leader->rate_limiter_priority);
+                    write_group.leader->rate_limiter_priority,
+                    /*with_db_mutex=*/false, /*with_log_mutex=*/true);
   if (to_be_cached_state) {
     cached_recoverable_state_ = *to_be_cached_state;
     cached_recoverable_state_empty_ = false;
@@ -1974,6 +2002,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
       log_dir_synced_ = false;
       logs_.emplace_back(logfile_number_, new_log);
       alive_log_files_.push_back(LogFileNumberSize(logfile_number_));
+      alive_log_files_tail_ = alive_log_files_.rbegin();
     }
     log_write_mutex_.Unlock();
   }