Re: [PATCH net] vlan: Fix to delete vid only when by_dev has hw filter capable in vlan_vids_del_by_dev()

["Ziyang Xuan (William)" <william.xuanziyang@huawei.com>]

> On Tue, Aug 01, 2023 at 05:59:43PM +0800, Ziyang Xuan wrote:
>> diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
>> index 0beb44f2fe1f..79cf4f033b66 100644
>> --- a/net/8021q/vlan_core.c
>> +++ b/net/8021q/vlan_core.c
>> @@ -436,8 +436,11 @@ void vlan_vids_del_by_dev(struct net_device *dev,
>>  	if (!vlan_info)
>>  		return;
>>  
>> -	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
>> +	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
>> +		if (!vlan_hw_filter_capable(by_dev, vid_info->proto))
>> +			continue;
>>  		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
> 
> vlan_vids_add_by_dev() does not have this check which means that memory
> will leak [1] if the device is enslaved after the bond already has a
> VLAN upper.
> 
> I believe the correct solution is to explicitly set the STAG-related
> features [3] in the bond driver in a similar fashion to how it's done
> for the CTAG features. That way the bond driver will always propagate
> the VLAN info to its slaves.
> 
Thank you for your detailed analysis and valuable suggestions.
I will fix my patch according to your suggestions.

> Please check the team driver as well. I think it's suffering from the
> same problem. If so, please fix it in a separate patch.
> 
Yes, I will test, and fix it if there is the same bug.

Thank you.
William Xuan

> [1]
> unreferenced object 0xffff888103efbd00 (size 256):
>   comm "ip", pid 351, jiffies 4294763177 (age 19.697s)
>   hex dump (first 32 bytes):                                                          
>     00 10 7a 11 81 88 ff ff 00 00 00 00 00 00 00 00  ..z.............
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:                                                                          
>     [<ffffffff81a88c0a>] kmalloc_trace+0x2a/0xe0                     
>     [<ffffffff840f349c>] vlan_vid_add+0x30c/0x790
>     [<ffffffff840f4a68>] vlan_vids_add_by_dev+0x148/0x390
>     [<ffffffff82eea5e8>] bond_enslave+0xaf8/0x5d50
>     [<ffffffff837fbfd1>] do_set_master+0x1c1/0x220       
>     [<ffffffff8380711c>] do_setlink+0xa0c/0x3fa0  
>     [<ffffffff8381ee09>] __rtnl_newlink+0xc09/0x18c0
>     [<ffffffff8381fb2c>] rtnl_newlink+0x6c/0xa0 
>     [<ffffffff8381d4ee>] rtnetlink_rcv_msg+0x43e/0xe00
>     [<ffffffff83a2c920>] netlink_rcv_skb+0x170/0x440
>     [<ffffffff83a2a2cf>] netlink_unicast+0x53f/0x810  
>     [<ffffffff83a2af0b>] netlink_sendmsg+0x96b/0xe90
>     [<ffffffff83708e0f>] ____sys_sendmsg+0x30f/0xa70
>     [<ffffffff837129fa>] ___sys_sendmsg+0x13a/0x1e0 
>     [<ffffffff83712c6c>] __sys_sendmsg+0x11c/0x1f0  
>     [<ffffffff842fe5c8>] do_syscall_64+0x38/0x80   
> unreferenced object 0xffff888112ffab60 (size 32):
>   comm "ip", pid 351, jiffies 4294763177 (age 19.697s)
>   hex dump (first 32 bytes):
>     a0 bd ef 03 81 88 ff ff a0 bd ef 03 81 88 ff ff  ................
>     88 a8 0a 00 01 00 00 00 cc cc cc cc cc cc cc cc  ................
>   backtrace:
>     [<ffffffff81a88c0a>] kmalloc_trace+0x2a/0xe0
>     [<ffffffff840f3599>] vlan_vid_add+0x409/0x790
>     [<ffffffff840f4a68>] vlan_vids_add_by_dev+0x148/0x390
>     [<ffffffff82eea5e8>] bond_enslave+0xaf8/0x5d50
>     [<ffffffff837fbfd1>] do_set_master+0x1c1/0x220
>     [<ffffffff8380711c>] do_setlink+0xa0c/0x3fa0
>     [<ffffffff8381ee09>] __rtnl_newlink+0xc09/0x18c0
>     [<ffffffff8381fb2c>] rtnl_newlink+0x6c/0xa0
>     [<ffffffff8381d4ee>] rtnetlink_rcv_msg+0x43e/0xe00
>     [<ffffffff83a2c920>] netlink_rcv_skb+0x170/0x440
>     [<ffffffff83a2a2cf>] netlink_unicast+0x53f/0x810
>     [<ffffffff83a2af0b>] netlink_sendmsg+0x96b/0xe90
>     [<ffffffff83708e0f>] ____sys_sendmsg+0x30f/0xa70
>     [<ffffffff837129fa>] ___sys_sendmsg+0x13a/0x1e0
>     [<ffffffff83712c6c>] __sys_sendmsg+0x11c/0x1f0
>     [<ffffffff842fe5c8>] do_syscall_64+0x38/0x80
> 
> [2]
> #!/bin/bash
> 
> ip link add name dummy1 type dummy
> ip link add bond1 type bond mode 802.3ad
> ip link add link bond1 name bond1.10 type vlan id 10 protocol 802.1ad
> ip link set dev dummy1 master bond1
> ip link del dev dummy1
> 
> [3]
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 484c9e3e5e82..447b06ea4fc9 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -5901,7 +5901,9 @@ void bond_setup(struct net_device *bond_dev)
>  
>         bond_dev->hw_features = BOND_VLAN_FEATURES |
>                                 NETIF_F_HW_VLAN_CTAG_RX |
> -                               NETIF_F_HW_VLAN_CTAG_FILTER;
> +                               NETIF_F_HW_VLAN_CTAG_FILTER |
> +                               NETIF_F_HW_VLAN_STAG_RX |
> +                               NETIF_F_HW_VLAN_STAG_FILTER;
>  
>         bond_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL;
>         bond_dev->features |= bond_dev->hw_features;
> 
>> +	}
>>  }
>>  EXPORT_SYMBOL(vlan_vids_del_by_dev);
>>  
>> -- 
>> 2.25.1
>>
>>
> 
> .
>