From: Feng Tang feng.tang@intel.com
[ Upstream commit ec4fe4bcc584b55e24e8d1768f5510a62c0fd619 ]
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@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 a9ea966877f2..dda8e79d4b27 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,