From: Tom Lane <tgl@sss.pgh.pa.us>
To: =?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>
cc: pgsql-hackers@postgresql.org
Subject: Re: [PATCH] snowball: fix potential NULL dereference
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Comments: In-reply-to =?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>
	message dated "Tue, 11 Feb 2025 11:52:29 +0300"
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Date: Tue, 11 Feb 2025 11:53:37 -0500
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BC?=3D <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_e=
nv().
> 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