bonding: Fix incorrect deletion of ETH_P_8021AD protocol vid from slaves
BUG_ON(!vlan_info) is triggered in unregister_vlan_dev() with following testcase: # ip netns add ns1 # ip netns exec ns1 ip link add bond0 type bond mode 0 # ip netns exec ns1 ip link add bond_slave_1 type veth peer veth2 # ip netns exec ns1 ip link set bond_slave_1 master bond0 # ip netns exec ns1 ip link add link bond_slave_1 name vlan10 type vlan id 10 protocol 802.1ad # ip netns exec ns1 ip link add link bond0 name bond0_vlan10 type vlan id 10 protocol 802.1ad # ip netns exec ns1 ip link set bond_slave_1 nomaster # ip netns del ns1 The logical analysis of the problem is as follows: 1. create ETH_P_8021AD protocol vlan10 for bond_slave_1: register_vlan_dev() vlan_vid_add() vlan_info_alloc() __vlan_vid_add() // add [ETH_P_8021AD, 10] vid to bond_slave_1 2. create ETH_P_8021AD protocol bond0_vlan10 for bond0: register_vlan_dev() vlan_vid_add() __vlan_vid_add() vlan_add_rx_filter_info() if (!vlan_hw_filter_capable(dev, proto)) // condition established because bond0 without NETIF_F_HW_VLAN_STAG_FILTER return 0; if (netif_device_present(dev)) return dev->netdev_ops->ndo_vlan_rx_add_vid(dev, proto, vid); // will be never called // The slaves of bond0 will not refer to the [ETH_P_8021AD, 10] vid. 3. detach bond_slave_1 from bond0: __bond_release_one() vlan_vids_del_by_dev() list_for_each_entry(vid_info, &vlan_info->vid_list, list) vlan_vid_del(dev, vid_info->proto, vid_info->vid); // bond_slave_1 [ETH_P_8021AD, 10] vid will be deleted. // bond_slave_1->vlan_info will be assigned NULL. 4. delete vlan10 during delete ns1: default_device_exit_batch() dev->rtnl_link_ops->dellink() // unregister_vlan_dev() for vlan10 vlan_info = rtnl_dereference(real_dev->vlan_info); // real_dev of vlan10 is bond_slave_1 BUG_ON(!vlan_info); // bond_slave_1->vlan_info is NULL now, bug is triggered!!! Add S-VLAN tag related features support to bond driver. So the bond driver will always propagate the VLAN info to its slaves. Fixes: 8ad227ff ("net: vlan: add 802.1ad support") Suggested-by: Ido Schimmel <idosch@idosch.org> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20230802114320.4156068-1-william.xuanziyang@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>
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