Wang LiangandGreg Kroah-Hartman 52b44d8c65 net: fix NULL pointer dereference in l3mdev_l3_rcv ...

[ Upstream commit 0032c99e83 ]

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: c675e06a98 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2025-11-24 10:30:04 +01:00

..

ipvlan_core.c

ipvlan: ensure network headers are in skb linear part

2025-03-07 16:45:40 +01:00

ipvlan_l3s.c

net: fix NULL pointer dereference in l3mdev_l3_rcv

2025-11-24 10:30:04 +01:00

ipvlan_main.c

…

ipvlan.h

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ipvtap.c

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Makefile

…