From b68ac32580445b261cc8bde5dee8037da9ab6917 Mon Sep 17 00:00:00 2001
From: Vamsi-2581 <245859299+Vamsi-2581@users.noreply.github.com>
Date: Tue, 20 Oct 2026 21:00:36 +0530
Subject: [PATCH 1/2] fix(proxy): release Presidio session lock before requests

---
 litellm/proxy/guardrails/guardrail_hooks/presidio.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/litellm/proxy/guardrails/guardrail_hooks/presidio.py b/litellm/proxy/guardrails/guardrail_hooks/presidio.py
index cadc9ca689b..cc11c09ec64 100644
--- a/litellm/proxy/guardrails/guardrail_hooks/presidio.py
+++ b/litellm/proxy/guardrails/guardrail_hooks/presidio.py
@@ -388,7 +388,8 @@ class _OPTIONAL_PresidioPIIMasking(CustomGuardrail):
             async with self._session_lock:
                 if self._http_session is None or self._http_session.closed:
                     self._http_session = aiohttp.ClientSession()
-                yield self._http_session
+                session = self._http_session
+            yield session
         else:
             # Background thread/loop -> use loop-bound session cache
             # This avoids "attached to a different loop" or "no running event loop" errors

From 181d841e294912f82c78a0912d4b42ddbb24360a Mon Sep 17 00:00:00 2001
From: Vamsi-2581 <245859299+Vamsi-2581@users.noreply.github.com>
Date: Tue, 20 Oct 2026 21:00:59 +0530
Subject: [PATCH 2/2] test(proxy): cover concurrent Presidio session use

---
 .../guardrail_hooks/test_presidio.py          | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/unit/proxy/guardrails/guardrail_hooks/test_presidio.py b/tests/unit/proxy/guardrails/guardrail_hooks/test_presidio.py
index bd1e9ae4068..e9c6f3ae6f5 100644
--- a/tests/unit/proxy/guardrails/guardrail_hooks/test_presidio.py
+++ b/tests/unit/proxy/guardrails/guardrail_hooks/test_presidio.py
@@ -5070,3 +5070,24 @@ def test_get_session_iterator_reuses_one_session_per_background_loop(
     assert len(sessions) == 10
     assert all(session is sessions[0] for session in sessions)
     assert presidio_guardrail._http_session is None
+
+
+@pytest.mark.asyncio
+async def test_get_session_iterator_does_not_hold_lock_while_session_is_in_use(
+    presidio_guardrail: OPTIONAL_PresidioPIIMasking,
+) -> None:
+    both_entered = asyncio.Event()
+    active_users = 0
+
+    async def use_session() -> None:
+        nonlocal active_users
+        async with presidio_guardrail._get_session_iterator():
+            active_users += 1
+            if active_users == 2:
+                both_entered.set()
+            await asyncio.wait_for(both_entered.wait(), timeout=1)
+
+    try:
+        await asyncio.gather(use_session(), use_session())
+    finally:
+        await presidio_guardrail._close_http_session()