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pgsql: Assert correct VM page passed to pruning 2+ messages / 1 participants [nested] [flat]
* pgsql: Assert correct VM page passed to pruning @ 2026-09-22 21:28 Melanie Plageman <melanieplageman@gmail.com> 0 siblings, 0 replies; 2+ messages in thread From: Melanie Plageman @ 2026-09-22 21:28 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Assert correct VM page passed to pruning Before pruning a heap page, we get the current status of the corresponding VM page. If the passed in vmbuffer isn't the right one, visibilitymap_get_status() will silently unpin it and pin the correct page. Pruning assumes the caller manages the vmbuffer lifecycle, so this would leave the caller with a stale VM reference and would leak the new VM pin. To avoid mistakes in development, assert that the correct VM page is pinned before beginning. Reported-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru> Discussion: https://postgr.es/m/CAAKRu_amj7qLF4c=9ijd=708Fu2G8gg-2EqwBu=aCdAHU2sPHg@mail.gmail.com Backpatch-through: 19 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/d8516db39dfa73042e3ba28f9efc78da4dd6792d Modified Files -------------- src/backend/access/heap/pruneheap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
* pgsql: Assert correct VM page passed to pruning @ 2026-09-22 21:29 Melanie Plageman <melanieplageman@gmail.com> 0 siblings, 0 replies; 2+ messages in thread From: Melanie Plageman @ 2026-09-22 21:29 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Assert correct VM page passed to pruning Before pruning a heap page, we get the current status of the corresponding VM page. If the passed in vmbuffer isn't the right one, visibilitymap_get_status() will silently unpin it and pin the correct page. Pruning assumes the caller manages the vmbuffer lifecycle, so this would leave the caller with a stale VM reference and would leak the new VM pin. To avoid mistakes in development, assert that the correct VM page is pinned before beginning. Reported-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru> Discussion: https://postgr.es/m/CAAKRu_amj7qLF4c=9ijd=708Fu2G8gg-2EqwBu=aCdAHU2sPHg@mail.gmail.com Backpatch-through: 19 Branch ------ REL_19_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/40cc0662ed7c0bf07e8c6534b1291ec5bcb5fee0 Modified Files -------------- src/backend/access/heap/pruneheap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2026-09-22 21:29 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-09-22 21:28 pgsql: Assert correct VM page passed to pruning Melanie Plageman <melanieplageman@gmail.com> 2026-09-22 21:29 pgsql: Assert correct VM page passed to pruning Melanie Plageman <melanieplageman@gmail.com>
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