Horton

Re: BUG #18247: Integer overflow leads to negative width

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Richard Guo <guofenglinux@gmail.com>
Cc: rekgrpth@gmail.com, pgsql-bugs@lists.postgresql.org
Date: 2023-12-14T14:43:45Z
Lists: pgsql-bugs 
Richard Guo <guofenglinux@gmail.com> writes:
> On Thu, Dec 14, 2023 at 5:29 PM PG Bug reporting form <
> noreply@postgresql.org> wrote:
>> EXPLAIN SELECT * FROM t;
>> QUERY PLAN
>> ------------------------------------------------------------
>> Seq Scan on t  (cost=0.00..10.00 rows=1 width=-2113929008)
>> (1 row)

> Can we just error out when an overflow occurs?

Probably better to clamp tuple width estimates to MaxAllocSize.
Anything larger would not correspond to reality anyhow.

			regards, tom lane

Commits

  1. Prevent integer overflow when forming tuple width estimates.

  2. compute_bitmap_pages' loop_count parameter should be double not int.