Re: strncpy is not a safe version of strcpy

From: Andres Freund <andres(at)2ndquadrant(dot)com>
To: Tomas Vondra <tv(at)fuzzy(dot)cz>
Cc: David Rowley <dgrowleyml(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: strncpy is not a safe version of strcpy
Date: 2013-11-15 14:41:45
Message-ID: 20131115144145.GB5888@awork2.anarazel.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On 2013-11-15 04:21:50 +0100, Tomas Vondra wrote:
> Hmm, you mean this piece of code?
>
> strncpy(saved_argv0, argv[0], MAXPGPATH);
>
> IMHO you're right that's probably broken, unless there's some checking
> happening before the call.

FWIW, argv0 is pretty much guaranteed to be shorter than MAXPGPATH since
MAXPGPATH is the longest a path can be, and argv[0] is either the executable's
name (if executed via PATH) or the path to the executable.
Now, you could probably write a program to exeve() a binary with argv[0]
being longer, but in that case you can also just put garbage in there.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Robert Haas 2013-11-15 14:51:32 Re: ERROR during end-of-xact/FATAL
Previous Message Jaime Casanova 2013-11-15 14:38:45 Re: Turning recovery.conf into GUCs