diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index da8bf327a3e9..df2ee65a33e3 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3209,11 +3209,11 @@ static int macsec_newlink(struct net *net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct macsec_dev *macsec = macsec_priv(dev); - struct net_device *real_dev; - int err; - sci_t sci; - u8 icv_len = DEFAULT_ICV_LEN; rx_handler_func_t *rx_handler; + u8 icv_len = DEFAULT_ICV_LEN; + struct net_device *real_dev; + int err, mtu; + sci_t sci; if (!tb[IFLA_LINK]) return -EINVAL; @@ -3229,7 +3229,11 @@ static int macsec_newlink(struct net *net, struct net_device *dev, if (data && data[IFLA_MACSEC_ICV_LEN]) icv_len = nla_get_u8(data[IFLA_MACSEC_ICV_LEN]); - dev->mtu = real_dev->mtu - icv_len - macsec_extra_len(true); + mtu = real_dev->mtu - icv_len - macsec_extra_len(true); + if (mtu < 0) + dev->mtu = 0; + else + dev->mtu = mtu; rx_handler = rtnl_dereference(real_dev->rx_handler); if (rx_handler && rx_handler != macsec_handle_frame)