Bug in batch tuplesort memory CLUSTER case (9.6 only)

From: Peter Geoghegan <pg(at)heroku(dot)com>
To: Pg Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Bug in batch tuplesort memory CLUSTER case (9.6 only)
Date: 2016-06-27 04:14:05
Message-ID: CAM3SWZR8x=e=o3o+tH6Y1Eae3kpdK4dyod8D6MYT=yC4+O7U7Q@mail.gmail.com
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In general, moving tuplesort.c batch memory caller tuples around
happens when batch memory needs to be recycled, or freed outright with

I failed to take into account that CLUSTER tuplesorts need an extra
step when moving caller tuples to a new location (i.e. when moving
HeapTuple caller tuples using memmove()), because their particular
variety of caller tuple happens to itself contain a pointer to
palloc()'d memory. Attached patch fixes this use-after-free bug.

Peter Geoghegan

Attachment Content-Type Size
0001-Fix-bug-in-batch-tuplesort-memory-with-CLUSTER.patch text/x-patch 8.6 KB


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