Re: mainline: x86_64: kernel panic: RIP: 0010:__xfrm_policy_check+0xcb/0x690

[Anders Roxell]

On 14 June 2018 at 13:15, William Tu <u9012063@xxxxxxxxx> wrote:
> On Tue, Jun 12, 2018 at 5:09 AM, Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
>> On 12 June 2018 at 10:34, Steffen Klassert <steffen.klassert@xxxxxxxxxxx> wrote:
>>> On Mon, Jun 11, 2018 at 10:11:46PM +0530, Naresh Kamboju wrote:
>>>> Kernel panic on x86_64 machine running mainline 4.17.0 kernel while testing
>>>> selftests bpf test_tunnel.sh test caused this kernel panic.
>>>> I have noticed this kernel panic start happening from
>>>> 4.17.0-rc7-next-20180529 and still happening on 4.17.0-next-20180608.
>>>>
>>>> [  213.638287] BUG: unable to handle kernel NULL pointer dereference
>>>> at 0000000000000008
>>>> ++[ ip xfrm poli  213.674036] PGD 0 P4D 0
>>>> [  213.674118] audit: type=1327 audit(1528917683.623:7):
>>>> proctitle=6970007866726D00706F6C69637900616464007372630031302E312E312E3130302F3332006473740031302E312E312E3230302F33320064697200696E00746D706C00737263003137322E31362E312E31303000647374003137322E31362E312E3230300070726F746F006573700072657169640031006D6F64650074756E6E
>>>> [  213.677950] Oops: 0000 [#1] SMP PTI
>>>> cy[ add src 10.1.  213.677952] CPU: 2 PID: 0 Comm: swapper/2 Tainted:
>>>> G        W         4.17.0-next-20180608 #1
>>>> [  213.677953] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
>>>> 2.0b 07/27/2017
>>>> [  213.726998] RIP: 0010:__xfrm_policy_check+0xcb/0x690
>>>> [  213.731962] Code: 80 3d 0a d8 f1 00 00 0f 84 c1 02 00 00 4c 8b 25
>>>> 2b af f4 00 e8 66 a6 6a ff 85 c0 74 0d 80 3d eb d7 f1 00 00 0f 84 d5
>>>> 02 00 00 <49> 8b 44 24 08 48 85 c0 74 0c 48 8d b5 78 ff ff ff 4c 89 ff
>>>> ff d0
>>>
>>> This looks like a bug that I've seen already. If it is what I think,
>>> then commit 2c205dd3981f ("netfilter: add struct nf_nat_hook and use
>>> it") introduced this bug.
>>>
>>> There was already a fix for this on the netdev list, but
>>> I don't know the current status of that patch:
>>>
>>> https://patchwork.ozlabs.org/patch/921387/
>>
>> Hi, I applied the patch and ran bpf/test_tunnel.sh and I I couldn't
>> see any crash.
>> However, the script never returned (I had to Ctrl+c to get back), any ideas ?
>> See log from the test below.
>>
>> Cheers,
>> Anders
>>
>> [0;92mPASS: xfrm tunnel[0m
>
> Hi Anders,
> I think it should return 0 if you reach the above line.

Yes it should but it didn't.
However, when I reran the test_tunnel.sh today with kernel next-20180613
I got back from from the script and the test passed "PASS: xfrm tunnel".
So I'm not sure what happened before. =/

> The console output looks pretty messy due to using 'tee'
> I will send a patch to make the output more readable.

Great.

Cheers,
Anders