Re: [PATCH] bms_prev_member() can read beyond the end of the array of allocated words - Mailing list pgsql-hackers

From Greg Burd
Subject Re: [PATCH] bms_prev_member() can read beyond the end of the array of allocated words
Date
Msg-id 266D00F2-4FE3-4352-ABE6-34ECB69BBFFC@getmailspring.com
Whole thread Raw
In response to Re: [PATCH] bms_prev_member() can read beyond the end of the array of allocated words  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [PATCH] bms_prev_member() can read beyond the end of the array of allocated words
List pgsql-hackers
On Aug 14 2025, at 10:06 am, Tom Lane <tgl@sss.pgh.pa.us> wrote:

> David Rowley <dgrowleyml@gmail.com> writes:
>> There's a comment saying:
>>  * "prevbit" must NOT be more than one above the highest possible bit
>> that can
>>  * be set at the Bitmapset at its current size.
>> So looks like it's the fault of the calling code and not an issue with
>> bms_prev_member().
> 
> Yeah.  But perhaps it'd be reasonable to put in an Assert checking
> that?

Hey Tom, thanks for chiming in on this one.  I had the same idea and
sent an updated patch.

-greg
 
> Grammar nitpick: comment should be more like "set in the Bitmapset".

I found this too, and also the "one above" part seemed wrong to me as well.

> 
>             regards, tom lane

best.

-greg




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