Re: [PATCH net v2] net: sunrpc: Fix an off by one in rpc_sockaddr2uaddr()

[Chuck Lever <chuck.lever@oracle.com>]

On Tue, Oct 24, 2023 at 11:58:20PM +0200, Christophe JAILLET wrote:
> The intent is to check if the strings' are truncated or not. So, >= should
> be used instead of >, because strlcat() and snprintf() return the length of
> the output, excluding the trailing NULL.
> 
> Fixes: a02d69261134 ("SUNRPC: Provide functions for managing universal addresses")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Hi Christophe -

Should these two be taken via the NFS client tree or do you intend
to include them in some other tree?


> ---
> v2: Fix cut'n'paste typo in subject
>     Add net in [PATCH...]
> ---
>  net/sunrpc/addr.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/sunrpc/addr.c b/net/sunrpc/addr.c
> index d435bffc6199..97ff11973c49 100644
> --- a/net/sunrpc/addr.c
> +++ b/net/sunrpc/addr.c
> @@ -284,10 +284,10 @@ char *rpc_sockaddr2uaddr(const struct sockaddr *sap, gfp_t gfp_flags)
>  	}
>  
>  	if (snprintf(portbuf, sizeof(portbuf),
> -		     ".%u.%u", port >> 8, port & 0xff) > (int)sizeof(portbuf))
> +		     ".%u.%u", port >> 8, port & 0xff) >= (int)sizeof(portbuf))
>  		return NULL;
>  
> -	if (strlcat(addrbuf, portbuf, sizeof(addrbuf)) > sizeof(addrbuf))
> +	if (strlcat(addrbuf, portbuf, sizeof(addrbuf)) >= sizeof(addrbuf))
>  		return NULL;
>  
>  	return kstrdup(addrbuf, gfp_flags);
> -- 
> 2.32.0
> 

-- 
Chuck Lever