Re: [PATCH] isdnloop: NUL-terminate strings from userspace

From: Vegard Nossum <vegard.nossum@oracle.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] isdnloop: NUL-terminate strings from userspace
Date: Fri, 07 Mar 2014 12:42:12 +0100	[thread overview]
Message-ID: <5319B094.7060709@oracle.com> (raw)
In-Reply-To: <20140307112655.GJ4774@mwanda>

On 03/07/2014 12:26 PM, Dan Carpenter wrote:
> On Fri, Mar 07, 2014 at 11:56:04AM +0100, Vegard Nossum wrote:
>> Both the in-kernel and BSD strlcpy() require that the source string is
>> NUL terminated.
>
> No.  You're obviously wrong.  What on earth?

Well, from lib/string.c:

size_t strlcpy(char *dest, const char *src, size_t size)
{
         size_t ret = strlen(src);

The BSD man page:

"Also note that strlcpy() and strlcat() only operate on true ``C'' 
strings.  This means that for strlcpy() src must be NUL-terminated and 
for strlcat() both src and dst must be NUL-terminated."

Vegard