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

[Neil Brown <neilb@suse.de>]

On Wednesday November 11, chuck.lever@oracle.com wrote:
> On 2009-11-11 Fabio Olive Leite wrote:
> > On 2009-11-11 Patroklos Argyroudis wrote:
> >> 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.
> > On a second note, why is '\n' needed there? You should only need  
> > '\0', as a '\n'
> 
> > at the end is not required by any of the string functions used to  
> > convert the
> > address. I believe you could go with buf[RPCBIND_MAXUADDRLEN+1] for  
> > the extra NUL only.
> 
> AFAICT, strict_strtoul() requires the '\n\0' termination.

	if ((*tail == '\0') ||
		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
		*res = val;
		return 0;
	}


allows, not requires.  Though admittedly that code isn't as clear as
one might like:
        if (tail[0] == 0 || (tail[0] == '\n' && tail[1] == 0) {
                .....
        }

NeilBrown