From: Donghee Na <donghee.na@python.org>
Date: Sat, 5 Oct 2024 02:27:32 +0000 (+0900)
Subject: gh-112804: Clamping timeout value for _PySemaphore_PlatformWait (gh-124914)
X-Git-Tag: v3.14.0a1~179
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a5fc50994a3fae46d0c3d496c4e1d5e00548a1b8;p=thirdparty%2FPython%2Fcpython.git

gh-112804: Clamping timeout value for _PySemaphore_PlatformWait (gh-124914)

* gh-112804: Clamping timeout value for _PySemaphore_PlatformWait

* Address code review

* nit
---

diff --git a/Python/parking_lot.c b/Python/parking_lot.c
index 841b1d71ea16..a7e9760e35d8 100644
--- a/Python/parking_lot.c
+++ b/Python/parking_lot.c
@@ -102,7 +102,14 @@ _PySemaphore_PlatformWait(_PySemaphore *sema, PyTime_t timeout)
         millis = INFINITE;
     }
     else {
-        millis = (DWORD) (timeout / 1000000);
+        PyTime_t div = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_TIMEOUT);
+        // Prevent overflow with clamping the result
+        if ((PyTime_t)PY_DWORD_MAX < div) {
+            millis = PY_DWORD_MAX;
+        }
+        else {
+            millis = (DWORD) div;
+        }
     }
     wait = WaitForSingleObjectEx(sema->platform_sem, millis, FALSE);
     if (wait == WAIT_OBJECT_0) {