Re: [PATCH] snowball: fix potential NULL dereference

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Коротков Максим <m.korotkov@postgrespro.ru>
Cc: pgsql-hackers@postgresql.org
Date: 2025-02-11T16:53:37Z
Lists: pgsql-hackers
=?utf-8?q?=D0=9A=D0=BE=D1=80=D0=BE=D1=82=D0=BA=D0=BE=D0=B2_=D0=9C=D0=B0=D0=BA=D1=81=D0=B8=D0=BC?= <m.korotkov@postgrespro.ru> writes:
> I found the case of potential NULL pointer dereference.
> In snowball/libstemmer/api.c if we transfer control to the SN_create_env() function
> by using the error label when there is a memory allocation error of z->p or z->S,
> we can then dereference the NULL pointer z->S in the function SN_close_env().
> Added the pointer check for avoiding a potential problem.

I believe you are right: OOM partway through SN_create_env would fail.
However, backend/snowball is not our code so applying our own local
patch is not the way to fix it.  You should report this upstream;
see src/backend/snowball/README.

(Whenever they apply the patch, we should then re-sync...)

			regards, tom lane



Commits

  1. Avoid null pointer dereference crash after OOM in Snowball stemmers.

  2. Update to latest Snowball sources.