Horton

Re: glibc qsort() vulnerability

Mats Kindahl <mats@timescale.com>

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From: Mats Kindahl <mats@timescale.com>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@lists.postgresql.org
Date: 2024-02-08T11:01:22Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Use new overflow-safe integer comparison functions.

  2. Introduce overflow-safe integer comparison functions.

  3. Replace calls to pg_qsort() with the qsort() macro.

  4. Switch over to using our own qsort() all the time, as has been proposed

On Wed, Feb 7, 2024 at 9:56 PM Nathan Bossart <nathandbossart@gmail.com>
wrote:

> On Wed, Feb 07, 2024 at 08:46:56PM +0200, Heikki Linnakangas wrote:
> > Doesn't hurt to fix the comparison functions, and +1 on using the same
> > pattern everywhere.
>
> I attached a new version of the patch with some small adjustments.  I
> haven't looked through all in-tree qsort() comparators to see if any others
> need to be adjusted, but we should definitely do so as part of this thread.
> Mats, are you able to do this?
>

Sure, I checked them and the only ones remaining are those using int16.
Shall I modify those as well?


> > However, we use our qsort() with user-defined comparison functions, and
> we
> > cannot make any guarantees about what they might do. So we must ensure
> that
> > our qsort() doesn't overflow, no matter what the comparison function
> does.
> >
> > Looking at our ST_SORT(), it seems safe to me.
>
> Cool.
>
> --
> Nathan Bossart
> Amazon Web Services: https://aws.amazon.com
>