Re: [PATCH] netfilter: xt_TCPOPTSTRIP: fix possible mangling beyond packet boundary

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Wed, May 15, 2013 at 04:48:24PM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > On Wed, May 15, 2013 at 02:33:36PM +0200, Florian Westphal wrote:
> > > > +	const struct xt_tcpoptstrip_target_info *info = par->targinfo;
> > > >  	unsigned int optl, i, j;
> > > >  	struct tcphdr *tcph;
> > > >  	u_int16_t n, o;
> > > >  	u_int8_t *opt;
> > > > +	int len;
> > > > +
> > > [..]
> > > > +	len = skb->len - tcphoff;
> > > > +	if (len < sizeof(struct tcphdr))
> > > 
> > > I think this needs a cast 'if (len < (int) sizeof( ...?
> > 
> > I'm not hitting any compilation warning.
> 
> len is signed, thats why i asked, and, afair recall sizeof
> is unsigned and thus len is treated as unsigned.

Right. I'll fix it, thanks.