From: Wang Liang wangliang74@huawei.com

[ Upstream commit 0032c99e83b9ce6d5995d65900aa4b6ffb501cce ]

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 Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250321090353.1170545-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Rajani Kantha 681739313@139.com --- drivers/net/ipvlan/ipvlan_l3s.c | 1 - 1 file changed, 1 deletion(-)

diff --git a/drivers/net/ipvlan/ipvlan_l3s.c b/drivers/net/ipvlan/ipvlan_l3s.c index d5b05e803219..ca35a50bb640 100644 --- a/drivers/net/ipvlan/ipvlan_l3s.c +++ b/drivers/net/ipvlan/ipvlan_l3s.c @@ -224,5 +224,4 @@ 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; }