Horton

Thread

Commits

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

  2. Update to latest Snowball sources.

  1. [PATCH] snowball: fix potential NULL dereference

    m.korotkov@postgrespro.ru — 2025-02-11T08:52:29Z

    Hi all,
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.
---
Best regards, Korotkov Maksim
PostgresPro
m.korotkov@postgrespro.ru

  2. Re: [PATCH] snowball: fix potential NULL dereference

    Tom Lane <tgl@sss.pgh.pa.us> — 2025-02-11T16:53:37Z

    =?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

  3. Re: [PATCH] snowball: fix potential NULL dereference

    m.korotkov@postgrespro.ru — 2025-02-17T12:12:25Z

    Hi
On 2025-02-11 19:53, Tom Lane wrote:
> You should report this upstream;
> (Whenever they apply the patch, we should then re-sync...)

FYI, the patch to fix this problem was applied by upstream.
---
Best regards, Korotkov Maksim
PostgresPro
m.korotkov@postgrespro.ru

  4. Re: [PATCH] snowball: fix potential NULL dereference

    Tom Lane <tgl@sss.pgh.pa.us> — 2025-02-18T16:13:48Z

    Maksim Korotkov <m.korotkov@postgrespro.ru> writes:
> On 2025-02-11 19:53, Tom Lane wrote:
>> You should report this upstream;
>> (Whenever they apply the patch, we should then re-sync...)

> FYI, the patch to fix this problem was applied by upstream.

Thanks.  Barring objections, I'll do a full resync per
src/backend/snowball/README on HEAD, and then extract just
the null-dereference fix to apply to our back branches.

			regards, tom lane