Re: [PATCH v2 2/3] net: ethernet: mvpp2_main: fix possible OOB write in mvpp2_ethtool_get_rxnfc()

[Marcin Wojtas]

pt., 8 wrz 2023 o 08:21 Hangyu Hua <hbh25y@xxxxxxxxx> napisał(a):
>
> rules is allocated in ethtool_get_rxnfc and the size is determined by
> rule_cnt from user space. So rule_cnt needs to be check before using
> rules to avoid OOB writing or NULL pointer dereference.
>
> Fixes: 90b509b39ac9 ("net: mvpp2: cls: Add Classification offload support")
> Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> ---
>  drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index eb74ccddb440..21c3f9b015c8 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -5586,6 +5586,11 @@ static int mvpp2_ethtool_get_rxnfc(struct net_device *dev,
>                 break;
>         case ETHTOOL_GRXCLSRLALL:
>                 for (i = 0; i < MVPP2_N_RFS_ENTRIES_PER_FLOW; i++) {
> +                       if (loc == info->rule_cnt) {
> +                               ret = -EMSGSIZE;
> +                               break;
> +                       }
> +
>                         if (port->rfs_rules[i])
>                                 rules[loc++] = i;
>                 }

Reviewed-by: Marcin Wojtas <mw@xxxxxxxxxxxx>

Thanks,
Marcin