Bug#914429: nftables: Delete and Flush lead to device or resource busy with segmentation fault

[Eike Lohmann <e.lohmann@ic3s.de>]

Hi Arturo,

thanks for your quick reply.

Like described in my example, there is no reference to C_TestChain.


# nft delete chain filter C_TestChain
Error: Could not process rule: Device or resource busy
delete chain filter C_TestChain

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

what is left and can we delete it via an complete flush?

# nft list table filter -na
table ip filter { # handle 2
    chain FORWARD { # handle 1
        type filter hook forward priority 0; policy accept;
    }

    chain vpn_master { # handle 2
    }

    chain C_TestChain { # handle 5
    }
}

# nft flush ruleset
Segmentation fault

Regards, Eike


Am 23.11.18 um 11:59 schrieb Arturo Borrero Gonzalez:
> Control: severity -1 normal
> Control: reassign -1 linux
> Control: fixed -1 4.18.20-1
>
> On 11/23/18 11:32 AM, Eike Lohmann wrote:
>> # nft delete chain filter C_TestChain
>> Error: Could not process rule: Device or resource busy
>> delete chain filter C_TestChain
>>
> This is not a bug. This means that the C_TestChain chain is referenced
> by other objects within the ruleset, thus you can't delete it.
>
> Please, check your ruleset.
>
>> # nft flush ruleset
>> Segmentation fault
>>
> This is a kernel error which leads the userspace application to crash.
>
> Is fixed by this linux kernel patch:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7acfda539c0b9636a58bfee56abfb3aeee806d96
>
> This should be included in linux 4.18.20-1.
>
> Thanks for reporting!