| Message ID | 20250321090353.1170545-1-wangliang74@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v2] net: fix NULL pointer dereference in l3mdev_l3_rcv | expand |
diff --git a/drivers/net/ipvlan/ipvlan_l3s.c b/drivers/net/ipvlan/ipvlan_l3s.c index b4ef386bdb1b..7c017fe35522 100644 --- a/drivers/net/ipvlan/ipvlan_l3s.c +++ b/drivers/net/ipvlan/ipvlan_l3s.c @@ -226,5 +226,4 @@ void ipvlan_l3s_unregister(struct ipvl_port *port) dev->priv_flags &= ~IFF_L3MDEV_RX_HANDLER; ipvlan_unregister_nf_hook(read_pnet(&port->pnet)); - dev->l3mdev_ops = NULL; }
When delete l3s ipvlan: ip link del link eth0 ipvlan1 type ipvlan mode l3s This may cause a null pointer dereference: Call trace: ip_rcv_finish+0x48/0xd0 ip_rcv+0x5c/0x100 __netif_receive_skb_one_core+0x64/0xb0 __netif_receive_skb+0x20/0x80 process_backlog+0xb4/0x204 napi_poll+0xe8/0x294 net_rx_action+0xd8/0x22c __do_softirq+0x12c/0x354 This is because l3mdev_l3_rcv() visit dev->l3mdev_ops after ipvlan_l3s_unregister() assign the dev->l3mdev_ops to NULL. The process like this: (CPU1) | (CPU2) l3mdev_l3_rcv() | check dev->priv_flags: | master = skb->dev; | | | ipvlan_l3s_unregister() | set dev->priv_flags | dev->l3mdev_ops = NULL; | visit master->l3mdev_ops | To avoid this by do not set dev->l3mdev_ops when unregister l3s ipvlan. Suggested-by: David Ahern <dsahern@kernel.org> Fixes: c675e06a98a4 ("ipvlan: decouple l3s mode dependencies from other modes") Signed-off-by: Wang Liang <wangliang74@huawei.com> --- drivers/net/ipvlan/ipvlan_l3s.c | 1 - 1 file changed, 1 deletion(-)