Re: may be a buffer overflow problem - Mailing list pgsql-hackers

From Daniel Gustafsson
Subject Re: may be a buffer overflow problem
Date
Msg-id 74BBCE2E-B024-426A-95F0-D560A1528F73@yesql.se
Whole thread Raw
In response to may be a buffer overflow problem  ("Winter Loo" <winterloo@126.com>)
Responses Re: may be a buffer overflow problem
Re: may be a buffer overflow problem
List pgsql-hackers
> On 14 Jun 2024, at 09:38, Winter Loo <winterloo@126.com> wrote:

> I find the definition of `sqlca->sqlstate` and it has only 5 bytes. When the statement
>
> ```c
> strncpy(sqlca->sqlstate, "YE001", sizeof(sqlca->sqlstate));
> ```
>
> get executed, `sqlca->sqlstate` will have no '\0' byte which makes me anxious when someone prints that as a string.

sqlstate is defined as not being unterminated fixed-length, leaving the callers
to handle termination.

> Indeed, I found the code(in src/interfaces/ecpg/ecpglib/misc.c) does that,
>
> fprintf(debugstream, "[NO_PID]: sqlca: code: %ld, state: %s\n",
> sqlca->sqlcode, sqlca->sqlstate);

This is indeed buggy and need to take the length into account, as per the
attached.  This only happens when in the undocumented regression test debug
mode which may be why it's gone unnoticed.

--
Daniel Gustafsson



Attachment

pgsql-hackers by date:

Previous
From: Bertrand Drouvot
Date:
Subject: Re: Avoid orphaned objects dependencies, take 3
Next
From: Laurenz Albe
Date:
Subject: Re: may be a buffer overflow problem