Re: Fwd: w_scan hangs on 6.3.7 and does not react on kill -9

From: Bagas Sanjaya
Date: Tue Jun 13 2023 - 08:34:16 EST


On 6/13/23 18:59, Linux regression tracking (Thorsten Leemhuis) wrote:
>
>
> On 13.06.23 13:23, Bagas Sanjaya wrote:
>> On 6/12/23 20:52, Bagas Sanjaya wrote:
>>> Hi,
>>>
>>> I notice a regression report on Bugzilla [1]. Quoting from it:
>>>
>>>> w_scan tool on kernel 6.3.7 hangs so badly that it cannot be killed by kill -9
>>>> I tried also w_scan_cpp 20230604 but it also fails I have 2040:8268 Hauppauge soloHD device as reported by lsusb. During reboot of the OS it prints a lot of kernel errors but it is after syslog is killed I guess and in syslog messages I do not see anything. On default Debian kernel 5.10.0-23 this problem does not exists.
>>>
>>>
>>> See Bugzilla for the full thread and attached dmesg and kernel config.
>>>
>>> Lukasz: On what hardware you have this regression? Also, it is really
>>> helpful if you can perform bisection (as outlined
>>> in Documentation/admin-guide/bug-bisect.html) to find the culprit,
>>> when developers can't figure it out by inspecting the code alone.
>>> Last but not least, please also try latest mainline (currently v6.4-rc6).
>>>
>>> Anyway, I'm adding it to regzbot:
>>>
>>> #regzbot introduced: v5.10..v6.3 https://bugzilla.kernel.org/show_bug.cgi?id=217540
>>> #regzbot title: w_scan zombie (unkillable) on kernel v6.3
>>
>> Another reporter on Bugzilla with similar regression as this one had
>> bisected the culprit, so:
>>
>> Hyunwoo Kim: It looks like this regression is caused by a backported
>> commit of yours. Would you like to take a look on it?
>>
>> #regzbot introduced: 8994830135b38b
>
> TWIMC, revert for mainline already in preparation, for details see:
>
> https://lore.kernel.org/all/23d5f9d6-f0db-a9af-1291-e9d6ac3cd126@xxxxxxxxxxxxx/
>

Hi Thorsten, thanks for additional discussion link. Telling regzbot:

#regzbot fix: Revert "media: dvb-core: Fix use-after-free on race condition at dvb_frontend"
#regzbot monitor: https://lore.kernel.org/all/23d5f9d6-f0db-a9af-1291-e9d6ac3cd126@xxxxxxxxxxxxx/

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