Horton

Avoid crash in rare case of concurrent DROP

Alvaro Herrera <alvherre@alvh.no-ip.org>

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Commit: d74b54b3ddf710926a44bf3f9c87c00e6f82d825
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: 2021-11-05T15:29:35Z
Releases: 15.0 
Avoid crash in rare case of concurrent DROP

When a role being dropped contains is referenced by catalog objects that
are concurrently also being dropped, a crash can result while trying to
construct the string that describes the objects.  Suppress that by
ignoring objects whose descriptions are returned as NULL.

The majority of relevant codesites were already cautious about this
already; we had just missed a couple.

This is an old bug, so backpatch all the way back.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/17126-21887f04508cb5c8@postgresql.org

Files

PathChange+/−
src/backend/catalog/dependency.c modified +20 −11
src/backend/catalog/pg_shdepend.c modified +6 −0

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