Re: [PATCH net-next] net: psample: fix flag being set in wrong skb

[Adrián Moreno]

On Wed, Jul 10, 2024 at 12:57:14AM GMT, Ilya Maximets wrote:
> On 7/9/24 22:34, Adrian Moreno wrote:
> > A typo makes PSAMPLE_ATTR_SAMPLE_RATE netlink flag be added to the wrong
> > sk_buff.
> >
> > Fixes: 7b1b2b60c63f ("net: psample: allow using rate as probability")
> > Signed-off-by: Adrian Moreno <amorenoz@xxxxxxxxxx>
> > ---
> >  net/psample/psample.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/psample/psample.c b/net/psample/psample.c
> > index f48b5b9cd409..11b7533067b8 100644
> > --- a/net/psample/psample.c
> > +++ b/net/psample/psample.c
> > @@ -498,7 +498,7 @@ void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,
> >  		goto error;
> >
> >  	if (md->rate_as_probability)
> > -		nla_put_flag(skb, PSAMPLE_ATTR_SAMPLE_PROBABILITY);
> > +		nla_put_flag(nl_skb, PSAMPLE_ATTR_SAMPLE_PROBABILITY);
> >
> >  	genlmsg_end(nl_skb, data);
> >  	genlmsg_multicast_netns(&psample_nl_family, group->net, nl_skb, 0,
>
> Uff.  Nasty.
>
> I'd say we should change the function argument to 'const' to avoid such
> issues in the future.  There is no reason for this function to modify
> the original packet.  What do you think?
>

Yes, that's probably a good idea.

Adrián.

> Best regards, Ilya Maximets.
>