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: 2024-02-08T11:31:14Z
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 Thu, Feb 8, 2024 at 12:01 PM Mats Kindahl <mats@timescale.com> wrote:

> 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?
>

Seems your additional patch dealt with at least one of the cases.


>
>
>> > 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
>>
>