Hello,
On Tue, 22 Jul 2014, Dan Carpenter wrote:
> On Mon, Jul 21, 2014 at 11:01:56PM +0300, Julian Anastasov wrote:
> > @@ -2333,13 +2339,12 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
> > struct ip_vs_dest_user_kern udest;
> > struct netns_ipvs *ipvs = net_ipvs(net);
> >
> > + BUILD_BUG_ON(sizeof(arg) > 256);
>
> 256 is off-by-one because u8 ranges from 0-255 so we are never able to
> copy 256 bytes into the "arg" buffer.
I'll change it to >= 256, to catch that we can
not hold such big size in unsigned char [gs]et_arglen and
also as an indication that we have to use allocated buffer
instead of stack.
> > - if (copylen > 128)
> > + if (*len < (int) copylen || *len < 0) {
> > + pr_err("get_ctl: len %d < %u\n", *len, copylen);
>
> Don't let users flood dmesg. Just return an error. (This can be
> triggered by non-root as well).
For now both set and get are privileged operations,
so we can keep it, it can catch if something wrong happens
with the structure sizes.
Regards
--
Julian Anastasov <ja@xxxxxx>
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