Re: BUG #19405: Assertion in eval_windowaggregates() fails due to integer overflow

From: Richard Guo <guofenglinux(at)gmail(dot)com>
To: Alexander Lakhin <exclusion(at)gmail(dot)com>
Cc: pgsql-bugs(at)lists(dot)postgresql(dot)org
Subject: Re: BUG #19405: Assertion in eval_windowaggregates() fails due to integer overflow
Date: 2026-02-14 11:00:51
Message-ID: CAMbWs4_jYG-vjN579aLuE7pf9PaZaPL9KCjPRN0kn3T+obE7hw@mail.gmail.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

On Sat, Feb 14, 2026 at 7:00 PM Alexander Lakhin <exclusion(at)gmail(dot)com> wrote:
> The patch works for me, but I've just discovered one more similar anomaly:
> SELECT SUM(i) OVER (ROWS BETWEEN 0x7fffffffffffffff FOLLOWING AND 1 FOLLOWING), i FROM t;
>
> ERROR: XX000: window frame head moved backward
> LOCATION: eval_windowaggregates, nodeWindowAgg.c:782

Right, I noticed this one too. Basically, nodeWindowAgg.c doesn't
check for overflow when adding startOffsetValue or endOffsetValue.
Since these values are provided by the user and can be arbitrarily
large, simple addition does not seem safe. I think we may need to
switch to overflow-aware integer operations in all relevant code.

- Richard

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Heikki Linnakangas 2026-02-14 11:42:02 Re: 17.8 standby crashes during WAL replay from 17.5 primary: "could not access status of transaction"
Previous Message Alexander Lakhin 2026-02-14 10:00:00 Re: BUG #19405: Assertion in eval_windowaggregates() fails due to integer overflow