[Bridge] hw csum failure introduced in linux-4.2

[Bridge] hw csum failure introduced in linux-4.2

[Álvaro Fernández Rojas]

 From linux-4.2 there's a "hw csum failure" for bridges using hardware 
checksums when IPv6 multicast traffic is received.

Here are some reports:
https://lkml.org/lkml/2015/12/1/699
https://bugzilla.redhat.com/show_bug.cgi?id=1266601
https://discourse.osmc.tv/t/hw-csum-failure/9990
https://github.com/raspberrypi/linux/issues/1259

I think it may have been introduced in commit 
9afd85c9e4552b276e2f4cfefd622bdeeffbbf26 (net: Export IGMP/MLD message 
validation code) but I haven't done any tests to confirm it.
Any help on this issue would be really appreciated.

Regards,
Álvaro.

Re: [Bridge] hw csum failure introduced in linux-4.2

[Stephen Hemminger]

On Fri, 22 Jan 2016 22:03:55 +0100
Álvaro Fernández Rojas <noltari@gmail.com> wrote:

>  From linux-4.2 there's a "hw csum failure" for bridges using hardware 
> checksums when IPv6 multicast traffic is received.
> 
> Here are some reports:
> https://lkml.org/lkml/2015/12/1/699
> https://bugzilla.redhat.com/show_bug.cgi?id=1266601
> https://discourse.osmc.tv/t/hw-csum-failure/9990
> https://github.com/raspberrypi/linux/issues/1259
> 
> I think it may have been introduced in commit 
> 9afd85c9e4552b276e2f4cfefd622bdeeffbbf26 (net: Export IGMP/MLD message 
> validation code) but I haven't done any tests to confirm it.
> Any help on this issue would be really appreciated.
> 
> Regards,
> Álvaro.

What hardware? You missed the kernel bugzilla? If it was reported
there I would have forwarded it to netdev@vger.kernel.org.

Can you reproduce it with 4.4?

Re: [Bridge] hw csum failure introduced in linux-4.2

[Álvaro Fernández Rojas]

Yes, I could reproduce it on OpenWrt using linux-4.4 on a Raspberry Pi 2.
https://gist.github.com/Noltari/5b1cfdecce5ed4bc08fd

No, I didn't open any issue on the kernel bugzilla.
If you want me to report it somewhere else I don't have any problem with it.

Regards,
Álvaro.

El 22/01/2016 a las 22:10, Stephen Hemminger escribió:
> On Fri, 22 Jan 2016 22:03:55 +0100
> Álvaro Fernández Rojas <noltari@gmail.com> wrote:
>
>>   From linux-4.2 there's a "hw csum failure" for bridges using hardware
>> checksums when IPv6 multicast traffic is received.
>>
>> Here are some reports:
>> https://lkml.org/lkml/2015/12/1/699
>> https://bugzilla.redhat.com/show_bug.cgi?id=1266601
>> https://discourse.osmc.tv/t/hw-csum-failure/9990
>> https://github.com/raspberrypi/linux/issues/1259
>>
>> I think it may have been introduced in commit
>> 9afd85c9e4552b276e2f4cfefd622bdeeffbbf26 (net: Export IGMP/MLD message
>> validation code) but I haven't done any tests to confirm it.
>> Any help on this issue would be really appreciated.
>>
>> Regards,
>> Álvaro.
> What hardware? You missed the kernel bugzilla? If it was reported
> there I would have forwarded it to netdev@vger.kernel.org.
>
> Can you reproduce it with 4.4?

Re: [Bridge] hw csum failure introduced in linux-4.2

[Linus Lüssing]

Hi Alvaro,

Did you have a chance to narrow it down to that commit yet? Would
be great if you could check whether reverting the following
commits helps:

c2d4fbd2163e ("bridge: fix igmpv3 / mldv2 report parsing")
a516993f0ac1 ("net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code")
9afd85c9e455 ("net: Export IGMP/MLD message validation code")

Or reverting all of the above plus:

3c9e4f870012 ("bridge: multicast: call skb_checksum_{simple_, }validate")


Will try to get my hands on a Pi 2, too.

Regards, Linus


PS: 4.4.0 did not have c2d4fb yet, that was added with 4.4.1. While
missing it does cause trouble, it should not cause a csum error.


On Fri, Jan 22, 2016 at 11:38:43PM +0100, Álvaro Fernández Rojas wrote:
> Yes, I could reproduce it on OpenWrt using linux-4.4 on a Raspberry Pi 2.
> https://gist.github.com/Noltari/5b1cfdecce5ed4bc08fd
> 
> No, I didn't open any issue on the kernel bugzilla.
> If you want me to report it somewhere else I don't have any problem with it.
> 
> Regards,
> Álvaro.
> 
> El 22/01/2016 a las 22:10, Stephen Hemminger escribió:
> > On Fri, 22 Jan 2016 22:03:55 +0100
> > Álvaro Fernández Rojas <noltari@gmail.com> wrote:
> >
> >>   From linux-4.2 there's a "hw csum failure" for bridges using hardware
> >> checksums when IPv6 multicast traffic is received.
> >>
> >> Here are some reports:
> >> https://lkml.org/lkml/2015/12/1/699
> >> https://bugzilla.redhat.com/show_bug.cgi?id=1266601
> >> https://discourse.osmc.tv/t/hw-csum-failure/9990
> >> https://github.com/raspberrypi/linux/issues/1259
> >>
> >> I think it may have been introduced in commit
> >> 9afd85c9e4552b276e2f4cfefd622bdeeffbbf26 (net: Export IGMP/MLD message
> >> validation code) but I haven't done any tests to confirm it.
> >> Any help on this issue would be really appreciated.
> >>
> >> Regards,
> >> Álvaro.
> > What hardware? You missed the kernel bugzilla? If it was reported
> > there I would have forwarded it to netdev@vger.kernel.org.
> >
> > Can you reproduce it with 4.4?
> 

Re: [Bridge] hw csum failure introduced in linux-4.2

[Linus Lüssing]

Ok, was able to borrow a Raspi 2 and indeed I can reproduce the
issue there.

Reverting these patches helps:

On Sat, Feb 13, 2016 at 03:35:28AM +0100, Linus Lüssing wrote:
> c2d4fbd2163e ("bridge: fix igmpv3 / mldv2 report parsing")
> a516993f0ac1 ("net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code")
> 9afd85c9e455 ("net: Export IGMP/MLD message validation code")

I'm on it.

Re: [Bridge] hw csum failure introduced in linux-4.2

[Álvaro Fernández Rojas]

Hi Linus,

Thanks for taking the time to look into this issue because unfortunately 
I don't have that time right now.
BTW, the error should also be reproducible on any Raspberry Pi v1 with 
ethernet.

Regards,
Álvaro.

El 14/02/2016 a las 12:57, Linus Lüssing escribió:
> Ok, was able to borrow a Raspi 2 and indeed I can reproduce the
> issue there.
>
> Reverting these patches helps:
>
> On Sat, Feb 13, 2016 at 03:35:28AM +0100, Linus Lüssing wrote:
>> c2d4fbd2163e ("bridge: fix igmpv3 / mldv2 report parsing")
>> a516993f0ac1 ("net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code")
>> 9afd85c9e455 ("net: Export IGMP/MLD message validation code")
> I'm on it.

Re: [Bridge] hw csum failure introduced in linux-4.2

[Linus Lüssing]

On Sat, Feb 13, 2016 at 03:35:28AM +0100, Linus Lüssing wrote:
> PS: 4.4.0 did not have c2d4fb yet, that was added with 4.4.1. While
> missing it does cause trouble, it should not cause a csum error.

Just for the record: I was wrong here, that patch was part of v4.4
already and even v4.3.