Re: Modern SHA2- based password hashes for pgcrypto

Am Sonntag, dem 06.04.2025 um 23:02 -0400 schrieb Andres Freund:
> Hi,
>
> On 2025-04-05 19:22:58 +0200, Alvaro Herrera wrote:
> > I have pushed this now, hoping it won't explode.
>
> I have a WIP patch that adds gcc specific allocator attributes for
> palloc et
> al. Just rebased that. It warns on the new code as follows:
>
> [1489/1804 42  82%] Compiling C object
> contrib/pgcrypto/pgcrypto.so.p/crypt-sha.c.o
> ../../../../../home/andres/src/postgresql/contrib/pgcrypto/crypt-
> sha.c: In function 'px_crypt_shacrypt':
> ../../../../../home/andres/src/postgresql/contrib/pgcrypto/crypt-
> sha.c:605:13: warning: pointer 'cp' may be used after 'pfree' [-Wuse-
> after-free]
>   605 |         *cp = '\0';
>       |         ~~~~^~~~~~
> ../../../../../home/andres/src/postgresql/contrib/pgcrypto/crypt-
> sha.c:533:9: note: call to 'pfree' here
>   533 |         pfree(s_bytes);
>       |         ^~~~~~~~~~~~~~
>
> And it sure seems to have a point.  I'm surprised this isn't causing
> wider
> issues...

Indeed. I think this assignment is useless anyways, since s_bytes is
already allocated with palloc0. I must have overseen this one when
rearranging code...but yes, strange that it didn't cause drama.

Thanks
Bernd