netdev - Re: [PATCH] dns: remove redundant zero length namelen check

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Message-ID: <17756.1555064391@warthog.procyon.org.uk>
Date:   Fri, 12 Apr 2019 11:19:51 +0100
From:   David Howells <dhowells@...hat.com>
To:     David Miller <davem@...emloft.net>
Cc:     dhowells@...hat.com, colin.king@...onical.com,
        netdev@...r.kernel.org, kernel-janitors@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] dns: remove redundant zero length namelen check

David Miller <davem@...emloft.net> wrote:

> > The zero namelen check is redundant as it has already been checked
> > for zero at the start of the function.  Remove the redundant check.
> > 
> > Addresses-Coverity: ("Logically Dead Code")
> > Signed-off-by: Colin Ian King <colin.king@...onical.com>
> 
> Applied to net-next.
> 
> However it does look like two sets of semantics were considered.
> In one case rejecting a zero namelen and in another having it
> mean whatever the strings length is modulo the max of 256.

It probably makes sense to merge the:

	if (namelen < 3 || namelen > 255)
		return -EINVAL;

check into the earlier:

	if (!name || namelen == 0)
		return -EINVAL;

check too.

David