From be72b9c378bfe99a3d175c98d36dc150229f4faf Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Mon, 30 Oct 2017 15:52:02 +0100 Subject: [PATCH] Fix autovacuum work item error handling In autovacuum's "work item" processing, a few strings were allocated in the current transaction's memory context, which goes away during error handling; if an error happened during execution of the work item, the pfree() calls to clean up afterwards would try to release already-released memory, possibly leading to a crash. In branch master, this was already fixed by commit 335f3d04e4c8, so backpatch that to REL_10_STABLE to fix the problem there too. As a secondary problem, verify that the autovacuum worker is connected to the right database for each work item; otherwise some items would be discarded by workers in other databases. Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20171014035732.GB31726@telsasoft.com --- src/backend/postmaster/autovacuum.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index c04c0b548d..48765bb01b 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -2531,6 +2531,8 @@ deleted: continue; if (workitem->avw_active) continue; + if (workitem->avw_database != MyDatabaseId) + continue; /* claim this one, and release lock while performing it */ workitem->avw_active = true; @@ -2606,9 +2608,7 @@ perform_work_item(AutoVacuumWorkItem *workitem) /* * Save the relation name for a possible error message, to avoid a catalog * lookup in case of an error. If any of these return NULL, then the - * relation has been dropped since last we checked; skip it. Note: they - * must live in a long-lived memory context because we call vacuum and - * analyze in different transactions. + * relation has been dropped since last we checked; skip it. */ Assert(CurrentMemoryContext == AutovacMemCxt);