Bug report

In socketmodule.c, a call is made to PyThread_allocate_lock to allocate a lock, but its return value is not checked.

	#if defined(USE_GETHOSTBYNAME_LOCK)
	netdb_lock = PyThread_allocate_lock();
	#endif

That same netdb_lock is later used without being checked for null-ness either.

	#ifdef USE_GETHOSTBYNAME_LOCK
	PyThread_acquire_lock(netdb_lock, 1);
	#endif
	_Py_COMP_DIAG_PUSH
	_Py_COMP_DIAG_IGNORE_DEPR_DECLS
	h = gethostbyname(name);
	_Py_COMP_DIAG_POP
	#endif /* HAVE_GETHOSTBYNAME_R */
	Py_END_ALLOW_THREADS
	/* Some C libraries would require addr.__ss_family instead of
	addr.ss_family.
	Therefore, we cast the sockaddr_storage into sockaddr to
	access sa_family. */
	sa = SAS2SA(&addr);
	ret = gethost_common(state, h, SAS2SA(&addr), sizeof(addr),
	sa->sa_family);
	#ifdef USE_GETHOSTBYNAME_LOCK
	PyThread_release_lock(netdb_lock);
	#endif

If PyThread_allocate_lock fails (due to being out of memory, that's the only failure case as far as I can tell), this will lead to a crash.

Once fix, the fix would have to be backported to 3.15 / 3.14 / 3.13 which have the same problem.