From: Jeff King <peff@peff.net>
Date: Thu, 03 Jan 2019 04:49:41 GMT
Subject: Re: [PATCH] banned.h: mark strncat() as banned
Message-ID: <20190103044941.GA20047@sigill.intra.peff.net>
In-Reply-To: <20190102093846.6664-1-e@80x24.org>

On Wed, Jan 02, 2019 at 09:38:46AM +0000, Eric Wong wrote:

> strncat() has the same quadratic behavior as strcat() and is
> difficult-to-read and bug-prone.  While it hasn't yet been a
> problem in git iself, strncat() found it's way into 'master'
> of cgit and caused segfaults on my system.

I'm in favor of this.

It doesn't have the "oops, I didn't NUL-terminate for you" problem that
strncpy() has. But it actually has the opposite problem! It will always
place a NUL, and you have to feed it sizeof(dst)-1 to avoid an overflow.

So I think it's important for safety (though I'd be fine banning it on
the quadratic grounds alone ;) ).

-Peff