There is a panic reported that on a system with x722 ethernet,
when doing the operations like:
#ip link add br0 type bridge
#ip link set eno1 master br0
#systemctl restart systemd-networkd
The system will panic "BUG: unable to handle kernel null pointer
dereference at 0000000000000034", with call chain:
i40iw_inetaddr_event
notifier_call_chain
blocking_notifier_call_chain
notifier_call_chain
__inet_del_ifa
inet_rtm_deladdr
rtnetlink_rcv_msg
netlink_rcv_skb
rtnetlink_rcv
netlink_unicast
netlink_sendmsg
sock_sendmsg
__sys_sendto
It is caused by "local_ipaddr = ntohl(in->ifa_list->ifa_address)",
while the in->ifa_list is NULL.
So add a check for the "in->ifa_list == NULL" case, and skip
the ARP operation accordingly.
Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
---
drivers/infiniband/hw/i40iw/i40iw_utils.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/hw/i40iw/i40iw_utils.c b/drivers/infiniband/hw/i40iw/i40iw_utils.c
index c5a8811..dfb0eea 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -173,7 +173,12 @@ int i40iw_inetaddr_event(struct notifier_block *notifier,
rcu_read_lock();
in = __in_dev_get_rcu(upper_dev);
- local_ipaddr = ntohl(in->ifa_list->ifa_address);
+
+ if (!in->ifa_list)
+ local_ipaddr = 0;
+ else
+ local_ipaddr = ntohl(in->ifa_list->ifa_address);
+
rcu_read_unlock();
} else {
local_ipaddr = ntohl(ifa->ifa_address);
@@ -185,6 +190,11 @@ int i40iw_inetaddr_event(struct notifier_block *notifier,
case NETDEV_UP:
/* Fall through */
case NETDEV_CHANGEADDR:
+
+ /* Just skip if no need to handle ARP cache */
+ if (!local_ipaddr)
+ break;
+
i40iw_manage_arp_cache(iwdev,
netdev->dev_addr,
&local_ipaddr,
--
2.7.4
