gh-112998: zipfile: fix extractall makedirs race condition

Author: pbsds

Lib/zipfile/__init__.py

@@ -1781,11 +1781,14 @@ def _extract_member(self, member, targetpath, pwd):
         # Create all upper directories if necessary.
         upperdirs = os.path.dirname(targetpath)
         if upperdirs and not os.path.exists(upperdirs):
-            os.makedirs(upperdirs)
+            os.makedirs(upperdirs, exist_ok=True)
 
         if member.is_dir():
             if not os.path.isdir(targetpath):
-                os.mkdir(targetpath)
+                try:
+                    os.mkdir(targetpath)
+                except FileExistsError:
+                    pass
             return targetpath
 
         with self.open(member, pwd=pwd) as source, \

Misc/NEWS.d/next/Library/2023-12-12-10-25-46.gh-issue-112998.F2QyD0.rst

@@ -0,0 +1,2 @@
+``zipfile`` - Avoid race condition creating parent directories when
+extracting concurrently.