Horton

Re: [PATCH] bms_prev_member() can read beyond the end of the array of allocated words

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Greg Burd <greg@burd.me>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-08-14T15:49:06Z
Lists: pgsql-hackers 
On Fri, 15 Aug 2025 at 03:43, Greg Burd <greg@burd.me> wrote:
> Well, that was rushed.  Apologies.

Would you be ok with adding the Assert after the "a == NULL" check?, i.e:

if (a == NULL || prevbit == 0)
    return -2;

/* Validate callers didn't give us something out of range */
Assert(prevbit <= a->nwords * BITS_PER_BITMAPWORD);

David

Commits

  1. Add Asserts to validate prevbit values in bms_prev_member