sfc: check for NULL efx->ptp_data in efx_ptp_event

If we receive a PTP event from the NIC when we haven't set up PTP state
in the driver, we attempt to read through a NULL pointer efx->ptp_data,
triggering a panic.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index eb75fbd11a01..d7a36829649a 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -1668,6 +1668,13 @@ void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev)
         struct efx_ptp_data *ptp = efx->ptp_data;
         int code = EFX_QWORD_FIELD(*ev, MCDI_EVENT_CODE);
 
+        if (!ptp) {
+                if (net_ratelimit())
+                        netif_warn(efx, drv, efx->net_dev,
+                                   "Received PTP event but PTP not set up\n");
+                return;
+        }
+
         if (!ptp->enabled)
                 return;