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

On Tue, Jun 12, 2018 at 5:09 AM, Anders Roxell [off-list ref] wrote:

On 12 June 2018 at 10:34, Steffen Klassert [off-list ref] wrote:

quoted

On Mon, Jun 11, 2018 at 10:11:46PM +0530, Naresh Kamboju wrote:

quoted

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

Thanks
William