Re: [PATCH] dynahash: add memory allocation failure check

Aleksander Alekseev <aleksander@timescale.com>

From: Aleksander Alekseev <aleksander@timescale.com>
To: m.korotkov@postgrespro.ru
Cc: pgsql-hackers@postgresql.org
Date: 2025-04-23T13:39:54Z
Lists: pgsql-hackers
Hi Maksim,

> I found a case of potential NULL pointer dereference.
> In src/backend/utils/hash/dynahash.c in function HTAB *hash_create() the
> result of the DynaHashAlloc() is used unsafely.
> The function DynaHashAlloc() calls MemoryContextAllocExtended() with
> MCXT_ALLOC_NO_OOM and can return a NULL pointer.
> Added the pointer check for avoiding a potential problem.

Thanks for the patch. It looks correct to me.

I didn't check if it needs to be back-ported and if it does - to how
many branches.

-- 
Best regards,
Aleksander Alekseev



Commits

  1. Avoid possibly-theoretical OOM crash hazard in hash_create().