4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marcus Huewe <suse-tux@xxxxxx> [ Upstream commit 7627ae6030f56a9a91a5b3867b21f35d79c16e64 ] When setting a neigh related sysctl parameter, we always send a NETEVENT_DELAY_PROBE_TIME_UPDATE netevent. For instance, when executing sysctl net.ipv6.neigh.wlp3s0.retrans_time_ms=2000 a NETEVENT_DELAY_PROBE_TIME_UPDATE netevent is generated. This is caused by commit 2a4501ae18b5 ("neigh: Send a notification when DELAY_PROBE_TIME changes"). According to the commit's description, it was intended to generate such an event when setting the "delay_first_probe_time" sysctl parameter. In order to fix this, only generate this event when actually setting the "delay_first_probe_time" sysctl parameter. This fix should not have any unintended side-effects, because all but one registered netevent callbacks check for other netevent event types (the registered callbacks were obtained by grepping for "register_netevent_notifier"). The only callback that uses the NETEVENT_DELAY_PROBE_TIME_UPDATE event is mlxsw_sp_router_netevent_event() (in drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c): in case of this event, it only accesses the DELAY_PROBE_TIME of the passed neigh_parms. Fixes: 2a4501ae18b5 ("neigh: Send a notification when DELAY_PROBE_TIME changes") Signed-off-by: Marcus Huewe <suse-tux@xxxxxx> Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/neighbour.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2927,7 +2927,8 @@ static void neigh_proc_update(struct ctl return; set_bit(index, p->data_state); - call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p); + if (index == NEIGH_VAR_DELAY_PROBE_TIME) + call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p); if (!dev) /* NULL dev means this is default value */ neigh_copy_dflt_parms(net, p, index); }