Subject: Re: [Bugme-new] [Bug 14546] New: Off-by-two stack buffer overflow in function rpc_uaddr2sockaddr() of net/sunrpc/addr.c

From: Fabio Olive Leite <[email-masked]>
Date: Wed, 11 Nov 2009 10:11:59 -0200

On 2009-11-11 Patroklos Argyroudis wrote:
> On Tue, Nov 10, 2009 at 06:38:05PM -0500, Chuck Lever wrote:
> > Why wouldn't you bump the size of the buffer by two as well?
> > Otherwise valid universal addresses that are RPCBIND_MAXUADDRLEN
> > bytes long will fail here.
> > 
> > >	memcpy(buf, uaddr, uaddr_len);
> 
> There is no need to increase the size of the buffer since the new
> check (if (uaddr_len > sizeof(buf) - 2)) will terminate the function
> in case the valid universal address is RPCBIND_MAXUADDRLEN bytes.

Failing to convert a valid address is incorrect and unexpected. What
Chuck meant is that since it is valid to have an address up to
RPCBIND_MAXUADDRLEN bytes long, the function should be able to work on
that, by having an internal buffer that allows for the extra "\n\0".

Cheers,
Fábio Olivé
-- 
ex sed lex awk yacc, e pluribus unix, amem
na matemática das idéias, permuta é igual a adição
e um debate inteligente implementa a multiplicação
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to [email-masked]
More majordomo info at  http://vger.kernel.org/majordomo-info.html