Re: [PATCH net-next v2 0/7] ethtool: allow dumping policies to user space

[Leon Romanovsky <leon@kernel.org>]

On Wed, Oct 07, 2020 at 10:29:01AM +0200, Johannes Berg wrote:
> On Wed, 2020-10-07 at 11:24 +0300, Leon Romanovsky wrote:
> > On Wed, Oct 07, 2020 at 09:30:51AM +0200, Johannes Berg wrote:
> > > On Wed, 2020-10-07 at 09:27 +0300, Leon Romanovsky wrote:
> > > > This series and my guess that it comes from ff419afa4310 ("ethtool: trim policy tables")
> > > > generates the following KASAN out-of-bound error.
> > >
> > > Interesting. I guess that is
> > >
> > > 	req_info->counts_only = tb[ETHTOOL_A_STRSET_COUNTS_ONLY];
> > >
> > > which basically means that before you never actually *use* the
> > > ETHTOOL_A_STRSET_COUNTS_ONLY flag, but of course it shouldn't be doing
> > > this ...
> > >
> > > Does this fix it?
> >
> > Yes, it fixed KASAN, but it we got new failure after that.
>
> Good.
>
> I'm not very familiar with ethtool netlink tbh :)
>
> > 11:07:51 player_id: 1 shell.py:62 [LinuxEthtoolAgent] DEBUG : running command(/opt/mellanox/ethtool/sbin/ethtool --set-channels eth2 combined 3) with pid: 13409
> > 11:07:51 player_id: 1 protocol.py:605 [OpSetChannels] ERROR : RC:1, STDERR:
> > netlink error: Unknown attribute type (offset 36)
> > netlink error: Invalid argument
>
> That's even stranger, since strict validation should've meant this was
> always rejected? Hmm.
>
> Oh, copy/paste error I guess, try this:

Thanks, it fixed and everything passed.



>
> diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
> index 8a85a4e6be9b..50d3c8896f91 100644
> --- a/net/ethtool/netlink.c
> +++ b/net/ethtool/netlink.c
> @@ -830,8 +830,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
>  		.cmd	= ETHTOOL_MSG_CHANNELS_SET,
>  		.flags	= GENL_UNS_ADMIN_PERM,
>  		.doit	= ethnl_set_channels,
> -		.policy = ethnl_channels_get_policy,
> -		.maxattr = ARRAY_SIZE(ethnl_channels_get_policy) - 1,
> +		.policy = ethnl_channels_set_policy,
> +		.maxattr = ARRAY_SIZE(ethnl_channels_set_policy) - 1,
>  	},
>  	{
>  		.cmd	= ETHTOOL_MSG_COALESCE_GET,
>
> johannes
>