[PATCH AUTOSEL for 4.9 043/100] i40iw: Receive netdev events post INET_NOTIFIER state

From: alexander . levin
Date: Tue Dec 12 2017 - 21:42:11 EST


From: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>

[ Upstream commit 871a8623d3b40221ad1103aff715dfee0aa4dacf ]

Netdev notification events are de-registered only when all
client iwdev instances are removed. If a single client is closed
and re-opened, netdev events could arrive even before the Control
Queue-Pair (CQP) is created, causing a NULL pointer dereference crash
in i40iw_get_cqp_request. Fix this by allowing netdev event
notification only after we have reached the INET_NOTIFIER state with
respect to device initialization.

Reported-by: Stefan Assmann <sassmann@xxxxxxxxxx>
Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
drivers/infiniband/hw/i40iw/i40iw_utils.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/infiniband/hw/i40iw/i40iw_utils.c b/drivers/infiniband/hw/i40iw/i40iw_utils.c
index 6fd043b1d714..7db2001775cb 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -159,6 +159,9 @@ int i40iw_inetaddr_event(struct notifier_block *notifier,
return NOTIFY_DONE;

iwdev = &hdl->device;
+ if (iwdev->init_state < INET_NOTIFIER)
+ return NOTIFY_DONE;
+
netdev = iwdev->ldev->netdev;
upper_dev = netdev_master_upper_dev_get(netdev);
if (netdev != event_netdev)
@@ -231,6 +234,9 @@ int i40iw_inet6addr_event(struct notifier_block *notifier,
return NOTIFY_DONE;

iwdev = &hdl->device;
+ if (iwdev->init_state < INET_NOTIFIER)
+ return NOTIFY_DONE;
+
netdev = iwdev->ldev->netdev;
if (netdev != event_netdev)
return NOTIFY_DONE;
@@ -280,6 +286,8 @@ int i40iw_net_event(struct notifier_block *notifier, unsigned long event, void *
if (!iwhdl)
return NOTIFY_DONE;
iwdev = &iwhdl->device;
+ if (iwdev->init_state < INET_NOTIFIER)
+ return NOTIFY_DONE;
p = (__be32 *)neigh->primary_key;
i40iw_copy_ip_ntohl(local_ipaddr, p);
if (neigh->nud_state & NUD_VALID) {
--
2.11.0