invalid memory alloc request size 576460752438159360

Hi,

We are getting same error a lot for more than 1 days from different schemas
in the same db.
< user=myuser db=mydb host=mydbip pid=18883 app=[unknown] time=2017-12-31
14:28:16.056 +03 > ERROR: invalid memory alloc request size
576460752438159360

CentOS Linux release 7.4.1708 (Core)
DB version: 9.6.6
Memory: 256GB
CPU 2.2 Ghz 24 core
Disk: SAN Multipath

* write_cache is disabled
* there is no incorrect work_mem parameter setting.
* logical dump is working, (maybe) no curruption in data.
* there is streaming replication, we do not repeat the error in the
replicas. (replicas in different minor versions, 9.6.4, 9.6.3 accordingly)
* we have large_object field, logical_dump also works with large_objects
fields.

Any idea?