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| author | Tomas Vondra <tomas.vondra@postgresql.org> | 2023-07-02 18:54:09 +0200 |
|---|---|---|
| committer | Tomas Vondra <tomas.vondra@postgresql.org> | 2023-07-02 20:03:30 +0200 |
| commit | 98640f960eb9ed80cf90de3ef5d2e829b785b3eb (patch) | |
| tree | 63c2616ee2fbb7f2b3c66fd0ca2f75f62bb0c459 | |
| parent | 0457109344b46f481f9bf09b85674695ba57c8e4 (diff) | |
| download | postgresql-98640f960eb9ed80cf90de3ef5d2e829b785b3eb.tar.gz postgresql-98640f960eb9ed80cf90de3ef5d2e829b785b3eb.zip | |
Fix memory leak in Incremental Sort rescans
The Incremental Sort had a couple issues, resulting in leaking memory
during rescans, possibly triggering OOM. The code had a couple of
related flaws:
1. During rescans, the sort states were reset but then also set to NULL
(despite the comment saying otherwise). ExecIncrementalSort then
sees NULL and initializes a new sort state, leaking the memory used
by the old one.
2. Initializing the sort state also automatically rebuilt the info about
presorted keys, leaking the already initialized info. presorted_keys
was also unnecessarily reset to NULL.
Patch by James Coleman, based on patches by Laurenz Albe and Tom Lane.
Backpatch to 13, where Incremental Sort was introduced.
Author: James Coleman, Laurenz Albe, Tom Lane
Reported-by: Laurenz Albe, Zu-Ming Jiang
Backpatch-through: 13
Discussion: https://postgr.es/m/b2bd02dff61af15e3526293e2771f874cf2a3be7.camel%40cybertec.at
Discussion: https://postgr.es/m/db03c582-086d-e7cd-d4a1-3bc722f81765%40inf.ethz.ch
| -rw-r--r-- | src/backend/executor/nodeIncrementalSort.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/src/backend/executor/nodeIncrementalSort.c b/src/backend/executor/nodeIncrementalSort.c index 34257ce34be..7683e3341cd 100644 --- a/src/backend/executor/nodeIncrementalSort.c +++ b/src/backend/executor/nodeIncrementalSort.c @@ -1140,7 +1140,6 @@ ExecReScanIncrementalSort(IncrementalSortState *node) node->outerNodeDone = false; node->n_fullsort_remaining = 0; node->bound_Done = 0; - node->presorted_keys = NULL; node->execution_status = INCSORT_LOADFULLSORT; @@ -1153,15 +1152,9 @@ ExecReScanIncrementalSort(IncrementalSortState *node) * cause a leak. */ if (node->fullsort_state != NULL) - { tuplesort_reset(node->fullsort_state); - node->fullsort_state = NULL; - } if (node->prefixsort_state != NULL) - { tuplesort_reset(node->prefixsort_state); - node->prefixsort_state = NULL; - } /* * If chgParam of subnode is not null, then the plan will be re-scanned by |