postgresql/src/backend/storage
Noah Misch 508acb901e Ban role pg_signal_backend from more superuser backend types.
Documentation says it cannot signal "a backend owned by a superuser".
On the contrary, it could signal background workers, including the
logical replication launcher.  It could signal autovacuum workers and
the autovacuum launcher.  Block all that.  Signaling autovacuum workers
and those two launchers doesn't stall progress beyond what one could
achieve other ways.  If a cluster uses a non-core extension with a
background worker that does not auto-restart, this could create a denial
of service with respect to that background worker.  A background worker
with bugs in its code for responding to terminations or cancellations
could experience those bugs at a time the pg_signal_backend member
chooses.  Back-patch to v11 (all supported versions).

Reviewed by Jelte Fennema-Nio.  Reported by Hemanth Sandrana and
Mahendrakar Srinivasarao.

Security: CVE-2023-5870
2023-11-06 06:14:17 -08:00
..
buffer Replace RelationOpenSmgr() with RelationGetSmgr(). 2022-11-17 16:54:30 -05:00
file Fix pg_truncate() on Windows. 2023-01-06 16:50:23 +13:00
freespace Replace RelationOpenSmgr() with RelationGetSmgr(). 2022-11-17 16:54:30 -05:00
ipc Ban role pg_signal_backend from more superuser backend types. 2023-11-06 06:14:17 -08:00
large_object Fix snapshot reference leak if lo_export fails. 2021-11-03 10:54:33 +02:00
lmgr Avoid calling proc_exit() in processes forked by system(). 2023-10-17 10:42:12 -05:00
page Initial pgindent and pgperltidy run for v14. 2021-05-12 13:14:10 -04:00
smgr Ensure that creation of an empty relfile is fsync'd at checkpoint. 2023-07-04 18:07:46 +03:00
sync Fix race between DROP TABLESPACE and checkpointing. 2022-03-16 17:20:50 +13:00
Makefile Refactor the fsync queue for wider use. 2019-04-04 23:38:38 +13:00