From 9d9471009704df84f4fedeb489308d87abe072c0 Mon Sep 17 00:00:00 2001
From: vanthinh6886 <vanthinh6886@gmail.com>
Date: Mon, 11 May 2026 21:22:23 +0700
Subject: [PATCH] fix: guard fcntl.flock(LOCK_UN) against OSError in finally
 blocks

When fcntl.flock(fd, LOCK_UN) raises OSError in a finally block,
the subsequent cleanup code (e.g., fd.close()) is skipped, causing
the file descriptor to leak and the lock to be held indefinitely.

This pattern existed in 5 files:
- agent/shell_hooks.py: _allowlist_editor()
- tools/skill_usage.py: _file_lock()
- tools/memory_tool.py: _file_lock()
- tools/environments/file_sync.py: sync_back()
- hermes_cli/auth.py: _credential_file_lock()

The Windows msvcrt path was already guarded with try/except in all
these files, but the POSIX fcntl path was not.

Fix: wrap each fcntl.flock(LOCK_UN) call in try/except OSError: pass,
matching the defensive pattern already used for the msvcrt path.

Fixes #21719
---
 agent/shell_hooks.py            | 5 ++++-
 hermes_cli/auth.py              | 5 ++++-
 tools/environments/file_sync.py | 5 ++++-
 tools/memory_tool.py            | 5 ++++-
 tools/skill_usage.py            | 5 ++++-
 5 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/agent/shell_hooks.py b/agent/shell_hooks.py
index d45851fea6cee..32e3a8d72ddbf 100644
--- a/agent/shell_hooks.py
+++ b/agent/shell_hooks.py
@@ -624,7 +624,10 @@ def _locked_update_approvals() -> Iterator[Dict[str, Any]]:
             yield data
             save_allowlist(data)
         finally:
-            fcntl.flock(lock_fh.fileno(), fcntl.LOCK_UN)
+            try:
+                fcntl.flock(lock_fh.fileno(), fcntl.LOCK_UN)
+            except OSError:
+                pass
 
 
 def _prompt_and_record(
diff --git a/hermes_cli/auth.py b/hermes_cli/auth.py
index 42e2f720874b5..d1fd7a19bf1d3 100644
--- a/hermes_cli/auth.py
+++ b/hermes_cli/auth.py
@@ -914,7 +914,10 @@ def _file_lock(
         finally:
             holder.depth = 0
             if fcntl:
-                fcntl.flock(lock_file.fileno(), fcntl.LOCK_UN)
+                try:
+                    fcntl.flock(lock_file.fileno(), fcntl.LOCK_UN)
+                except OSError:
+                    pass
             elif msvcrt:
                 try:
                     lock_file.seek(0)
diff --git a/tools/environments/file_sync.py b/tools/environments/file_sync.py
index b778be87eb8aa..5539ffef048ae 100644
--- a/tools/environments/file_sync.py
+++ b/tools/environments/file_sync.py
@@ -289,7 +289,10 @@ def _sync_back_locked(self, lock_path: Path) -> None:
             fcntl.flock(lock_fd, fcntl.LOCK_EX)
             self._sync_back_impl()
         finally:
-            fcntl.flock(lock_fd, fcntl.LOCK_UN)
+            try:
+                fcntl.flock(lock_fd, fcntl.LOCK_UN)
+            except OSError:
+                pass
             lock_fd.close()
 
     def _sync_back_impl(self) -> None:
diff --git a/tools/memory_tool.py b/tools/memory_tool.py
index 80ee3c63d67ee..e74722a2bc4cd 100644
--- a/tools/memory_tool.py
+++ b/tools/memory_tool.py
@@ -169,7 +169,10 @@ def _file_lock(path: Path):
             yield
         finally:
             if fcntl:
-                fcntl.flock(fd, fcntl.LOCK_UN)
+                try:
+                    fcntl.flock(fd, fcntl.LOCK_UN)
+                except OSError:
+                    pass
             elif msvcrt:
                 try:
                     fd.seek(0)
diff --git a/tools/skill_usage.py b/tools/skill_usage.py
index e25f1365446a3..2b4e9a44782d3 100644
--- a/tools/skill_usage.py
+++ b/tools/skill_usage.py
@@ -86,7 +86,10 @@ def _usage_file_lock():
         yield
     finally:
         if fcntl:
-            fcntl.flock(fd, fcntl.LOCK_UN)
+            try:
+                fcntl.flock(fd, fcntl.LOCK_UN)
+            except OSError:
+                pass
         elif msvcrt:
             try:
                 fd.seek(0)