public inbox for [email protected]  

help / color / mirror / Atom feed

From: Alexander Kuznetsov <[email protected]>
To: Daniel Gustafsson <[email protected]>
Cc: PostgreSQL Developers <[email protected]>
Cc: [email protected]
Cc: [email protected]
Subject: Re: [PATCH] Check for TupleTableSlot nullness before dereferencing
Date: Fri, 13 Dec 2024 11:54:35 +0300
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
	<[email protected]>
	<[email protected]>

Hello,

ping. What do you think about reasoning below? Maybe we should consider
proposing different patch for removing redundant check there?

09.10.2024 18:23, Alexander Kuznetsov wrote:
> 03.10.2024 12:48, Daniel Gustafsson wrote:
>>  From a quick reading we can only reach there after evaluating an expression, so
>> can it really be null though?  This code hasn't changed all that much since
>> 2009, if there was a reachable segfault on a null pointer deref I have a
>> feeling we'd heard about it by now so some extra care seems warranted to ensure
>> it's not a static analyzer false positive.
> Thanks for your response!
> It seems to me that dereferencing is possible under the following scenario:
> [...]
> This entire reasoning is based on the assumption that slot2 can theoretically be NULL, as there is such a check at line 968.
> Is it possible that no errors have occurred because this condition has always been satisfied and is, perhaps, redundant, or maybe I'm misunderstanding something?

-- 
Best regards,
Alexander Kuznetsov

view thread (6+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: [PATCH] Check for TupleTableSlot nullness before dereferencing
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox