Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH] exportfs: make root unexportable
To:     Roberto Bergantinos Corpas <rbergant@redhat.com>
Cc:     linux-nfs@vger.kernel.org
References: <20210329105435.17431-1-rbergant@redhat.com>
From:   Steve Dickson <SteveD@RedHat.com>
Message-ID: <a4722e51-5e42-605d-dbc0-bb00ee37d986@RedHat.com>
Date:   Wed, 7 Apr 2021 14:30:12 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.1
MIME-Version: 1.0
In-Reply-To: <20210329105435.17431-1-rbergant@redhat.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hello,

On 3/29/21 6:54 AM, Roberto Bergantinos Corpas wrote:
> If root of the filesystem is exported, it cannot be explicitly
> unexported, since unexportfs_parsed, in order to deal with trailing
> '/', will leave nlen at 0 for root exported case
> 
> Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
> ---
>  utils/exportfs/exportfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
> index 9fcae0b3..9b6f4f5a 100644
> --- a/utils/exportfs/exportfs.c
> +++ b/utils/exportfs/exportfs.c
> @@ -372,7 +372,7 @@ unexportfs_parsed(char *hname, char *path, int verbose)
>  	 * so need to deal with it.
>  	*/
>  	size_t nlen = strlen(path);
> -	while (path[nlen - 1] == '/')
> +	while ((path[nlen - 1] == '/') && (nlen > 1))
>  		nlen--;
I decided to use Ondrej's version sine the nlen is tested
first before the index into path was made.

steved.
>  
>  	for (exp = exportlist[htype].p_head; exp; exp = exp->m_next) {
>