The IFLA_NETKIT_PEER_INFO attribute can only be used during device creation, but not via changelink callback. Hence reject it there. Fixes: 35dfaad7188c ("netkit, bpf: Add bpf programmable net device") Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Acked-by: Nikolay Aleksandrov <razor@xxxxxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> --- v1 -> v2: - Switch error code from EACCES to EINVAL (Jakub) drivers/net/netkit.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/netkit.c b/drivers/net/netkit.c index 97bd6705c241..39171380ccf2 100644 --- a/drivers/net/netkit.c +++ b/drivers/net/netkit.c @@ -851,6 +851,12 @@ static int netkit_change_link(struct net_device *dev, struct nlattr *tb[], return -EACCES; } + if (data[IFLA_NETKIT_PEER_INFO]) { + NL_SET_ERR_MSG_ATTR(extack, data[IFLA_NETKIT_PEER_INFO], + "netkit peer info cannot be changed after device creation"); + return -EINVAL; + } + if (data[IFLA_NETKIT_POLICY]) { attr = data[IFLA_NETKIT_POLICY]; policy = nla_get_u32(attr); -- 2.21.0