Horton

Re: segmentation fault when cassert enabled

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2019-10-25T16:28:38Z
Lists: pgsql-hackers 
Jehan-Guillaume de Rorthais <jgdr@dalibo.com> writes:
> When investigating for the bug reported in thread "logical replication -
> negative bitmapset member not allowed", I found a way to seg fault postgresql
> only when cassert is enabled.
> ...
> I hadn't time to digg further yet. However, I don't understand why this crash
> is triggered when cassert is enabled.

Most likely, it's not so much assertions that provoke the crash as
CLOBBER_FREED_MEMORY, ie the actual problem here is use of already-freed
memory.

			regards, tom lane

Commits

  1. Fix subscriber invalid memory access on DDL.

  2. Fix memory allocation mistake