Re: glibc qsort() vulnerability

On Thu, Feb 8, 2024 at 12:01 PM Mats Kindahl <mats(at)timescale(dot)com> wrote:

> On Wed, Feb 7, 2024 at 9:56 PM Nathan Bossart <nathandbossart(at)gmail(dot)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
>>
>