Re: ath9k broken [was: Linux 5.7.3]

["Viktor Jägersküpper" <viktor_jaegerskuepper@freenet.de>]

Greg Kroah-Hartman wrote:
> On Fri, Jun 26, 2020 at 04:40:18PM +0200, Gabriel C wrote:
>> Am Fr., 26. Juni 2020 um 15:51 Uhr schrieb Gabriel C
>> <nix.or.die@googlemail.com>:
>>>
>>> Am Fr., 26. Juni 2020 um 15:40 Uhr schrieb Greg Kroah-Hartman
>>> <gregkh@linuxfoundation.org>:
>>>>
>>>> On Fri, Jun 26, 2020 at 01:48:59PM +0200, Gabriel C wrote:
>>>>> Am Do., 25. Juni 2020 um 12:52 Uhr schrieb Gabriel C
>>>>> <nix.or.die@googlemail.com>:
>>>>>>
>>>>>> Am Do., 25. Juni 2020 um 12:48 Uhr schrieb Gabriel C
>>>>>> <nix.or.die@googlemail.com>:
>>>>>>>
>>>>>>> Am Do., 25. Juni 2020 um 06:57 Uhr schrieb Jiri Slaby <jirislaby@kernel.org>:
>>>>>>>>
>>>>>>>> On 25. 06. 20, 0:05, Gabriel C wrote:
>>>>>>>>> Am Mi., 17. Juni 2020 um 18:13 Uhr schrieb Greg Kroah-Hartman
>>>>>>>>> <gregkh@linuxfoundation.org>:
>>>>>>>>>>
>>>>>>>>>> I'm announcing the release of the 5.7.3 kernel.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Hello Greg,
>>>>>>>>>
>>>>>>>>>> Qiujun Huang (5):
>>>>>>>>>>       ath9k: Fix use-after-free Read in htc_connect_service
>>>>>>>>>>       ath9k: Fix use-after-free Read in ath9k_wmi_ctrl_rx
>>>>>>>>>>       ath9k: Fix use-after-free Write in ath9k_htc_rx_msg
>>>>>>>>>>       ath9x: Fix stack-out-of-bounds Write in ath9k_hif_usb_rx_cb
>>>>>>>>>>       ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> We got a report on IRC about 5.7.3+ breaking a USB ath9k Wifi Dongle,
>>>>>>>>> while working fine on <5.7.3.
>>>>>>>>>
>>>>>>>>> I don't have myself such HW, and the reported doesn't have any experience
>>>>>>>>> in bisecting the kernel, so we build kernels, each with one of the
>>>>>>>>> above commits reverted,
>>>>>>>>> to find the bad commit.
>>>>>>>>>
>>>>>>>>> The winner is:
>>>>>>>>>
>>>>>>>>> commit 6602f080cb28745259e2fab1a4cf55eeb5894f93
>>>>>>>>> Author: Qiujun Huang <hqjagain@gmail.com>
>>>>>>>>> Date:   Sat Apr 4 12:18:38 2020 +0800
>>>>>>>>>
>>>>>>>>>     ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb
>>>>>>>>>
>>>>>>>>>     commit 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.
>>>>>>>>> ...
>>>>>>>>>
>>>>>>>>> Reverting this one fixed his problem.
>>>>>>>>
>>>>>>>> Obvious question: is 5.8-rc1 (containing the commit) broken too?
>>>>>>>
>>>>>>> Yes, it does, just checked.
>>>>>>>
>>>>>>> git tag --contains 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05
>>>>>>> v5.8-rc1
>>>>>>> v5.8-rc2
>>>>>>>
>>>>>>
>>>>>> Sorry, I read the wrong, I just woke up.
>>>>>>
>>>>>> We didn't test 5.8-rc{1,2} yet but we will today and let you know.
>>>>>>
>>>>>
>>>>> We tested 5.8-rc2 and it is broken too.
>>>>>
>>>>> The exact HW name is:
>>>>>
>>>>> TP-link tl-wn722n (Atheros AR9271 chip)
>>>>
>>>> Great!
>>>>
>>>> Can you work with the developers to fix this in Linus's tree first?
>>>
>>> I'm the man in the middle, but sure we will try patches or any suggestions
>>> from developers to identify and fix the problem.
>>>
>>>>
>>>> I bet they want to see the output of 'lsusb -v' for this device to see
>>>> if the endpoint calculations are correct...
>>>>
>>>
>>> Working on it. As soon the reporter gives me the output, I will post it here.
>>> I've told him to run it on a broken and one working kernel.
>>
>> That is from a good kernel with reverted commit
>> https://gist.github.com/AngryPenguinPL/07c8e2abd3b103eaf8978a39ad8577d1
>>
>> That is from the broken kernel without the commit reverted
>> https://gist.github.com/AngryPenguinPL/5cdc0dd16ce5e59ff3c32c048e2f5111
>>
>> This is from 5.7.5 kernel, I don't have yet a 5.8-rc2 package with the
>> reverted commit.
> 
> Did this ever get resolved?
> 
> thanks,
> 
> greg k-h
> 

This bug was also reported on the thread where it had been posted originally:
https://lore.kernel.org/linux-wireless/20200621020428.6417d6fb@natsu/

I am waiting for Kalle Valo to accept my patch (v2) which reverts the above
mentioned commit and which looks correct according to him. He wrote that he
would take a closer look at this as soon as he could.

I don't know how busy Kalle is, especially under the current circumstances.
I will remind him on Thursday (one week after his last e-mail). At the latest
I want this to be fixed with the 5.8 release. I think that the patch has to land
in several networking trees before it reaches the mainline kernel, so if I can
do anything to speed things up, just tell me.

Thanks,
Viktor