Re: BUG: unable to handle kernel NULL pointer dereference in fdb_find_rcu

From: Nikolay Aleksandrov
Date: Sat Dec 16 2017 - 04:29:24 EST


On 16/12/17 11:17, Nikolay Aleksandrov wrote:
> On 16/12/17 02:37, Andrei Vagin wrote:
>> Hi,
>>
>> We run criu tests for linux-next and today we get this bug:
>>
>> The kernel version is 4.15.0-rc3-next-20171215
>>
>> [ 235.397328] BUG: unable to handle kernel NULL pointer dereference
>> at 000000000000000c
>> [ 235.398624] IP: fdb_find_rcu+0x3c/0x130
> [snip]
>
> Hi,
> Thanks for the report, I've missed the changelink before dev creation case when I did

err, s/changelink/br_stp_change_bridge_id/
the other options are set after register_netdevice, this is the only one changed before

> the rhashtable conversion, some of the options do fdb lookups as part of their routine
> but we don't have the table initialized yet at that point.
> I'll send a fix after some testing.
>
> Thanks,
> Nik
>
>