[b43] ssh bug

[b43] ssh bug

[Evan Foss]

Hi B43-dev,

I am having trouble with the wifi card in my macbook pro 2012. It's a
BCM4331 and it hangs on ssh sessions.

I noticed it documented here.
https://wiki.archlinux.org/index.php/broadcom_wireless#SSH_freeze_for_BCM4331_with_b43

Is there some testing I could contribute to help fix this?

Thanks,
Evan Foss

[b43] ssh bug

[Larry Finger]

On 3/9/21 6:18 AM, Evan Foss wrote:
> Hi B43-dev,
> 
> I am having trouble with the wifi card in my macbook pro 2012. It's a
> BCM4331 and it hangs on ssh sessions.
> 
> I noticed it documented here.
> https://wiki.archlinux.org/index.php/broadcom_wireless#SSH_freeze_for_BCM4331_with_b43
> 
> Is there some testing I could contribute to help fix this?

Evan,

I do not have that card, thus I cannot test with that chip.

Given the age of the chips driven by b43, it is hard to imagine that there are 
any undisclosed proprietary secrets buried in the code. Broadcom should open 
source these old drivers.

What are the symptoms of the frozen sessions? Is there anything in particular 
that you are doing when it freezes? Does the freeze require rebooting either of 
the machines in question? Is anything logged in the dmesg output of either machine?

One useful test would be to run Wireshark to capture the data on the network 
interface. That capture file might have information that you would not want to 
share, but you should be able to supply only the last few packets.

A macbook of that vintage should be able to run wl. That may be your best option.

Larry

[b43] ssh bug

[Evan Foss]

Hi Larry,

I was offering to do testing. You might not remember me from like 15
years ago but I remember you. I was fighting a BCM4311 back then.

The symptoms are interesting. It freezes not just that session but all
other ssh sessions. I want to point out that it doesn't fail in all
ssh use cases, just file i/o. ssh terminal sessions don't cause it but
are also frozen when it hits. After the bug is triggered no new
sessions can be initiated.

What is fun is that it starts doing file i/o before it triggers so
some small number of bytes or time are required. So often I can see
whole directories on remote file systems just before it locks up.

I looked at wl a while back but I really wanted to contribute testing
to fix what remains the one unpatched bug in the driver.

Thanks,
Evan

On Tue, Mar 9, 2021 at 5:26 PM Larry Finger <Larry.Finger@lwfinger.net> wrote:
>
> On 3/9/21 6:18 AM, Evan Foss wrote:
> > Hi B43-dev,
> >
> > I am having trouble with the wifi card in my macbook pro 2012. It's a
> > BCM4331 and it hangs on ssh sessions.
> >
> > I noticed it documented here.
> > https://wiki.archlinux.org/index.php/broadcom_wireless#SSH_freeze_for_BCM4331_with_b43
> >
> > Is there some testing I could contribute to help fix this?
>
> Evan,
>
> I do not have that card, thus I cannot test with that chip.
>
> Given the age of the chips driven by b43, it is hard to imagine that there are
> any undisclosed proprietary secrets buried in the code. Broadcom should open
> source these old drivers.
>
> What are the symptoms of the frozen sessions? Is there anything in particular
> that you are doing when it freezes? Does the freeze require rebooting either of
> the machines in question? Is anything logged in the dmesg output of either machine?
>
> One useful test would be to run Wireshark to capture the data on the network
> interface. That capture file might have information that you would not want to
> share, but you should be able to supply only the last few packets.
>
> A macbook of that vintage should be able to run wl. That may be your best option.
>
> Larry
>
>


--
https://github.com/evanfoss

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