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Message-ID: <96903e75-63b4-8c59-6c78-0e641b1fc2c5@alu.unizg.hr>
Date:   Fri, 11 Nov 2022 09:44:05 +0100
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Subject: Re: BUG: kworker + systemd-udevd memory leaks found in 6.1.0-rc4
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To:     Thorsten Leemhuis <regressions@leemhuis.info>,
        linux-kernel@vger.kernel.org
Cc:     "regressions@lists.linux.dev" <regressions@lists.linux.dev>,
        Tejun Heo <tj@kernel.org>,
        Florian Mickler <florian@mickler.org>,
        systemd-devel@lists.freedesktop.org
References: <0d9c3f6c-3948-d5d1-bcc1-baf31141beaa@alu.unizg.hr>
 <a6b76ce0-0fb3-4434-cc3e-ab6f39fb1cf9@alu.unizg.hr>
 <3f1721d6-e5d9-8861-4e3c-802a711e71da@leemhuis.info>
From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
In-Reply-To: <3f1721d6-e5d9-8861-4e3c-802a711e71da@leemhuis.info>
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On 10.11.2022. 9:28, Thorsten Leemhuis wrote:

> This bug is confirmed in 6.1-rc4, among the "thermald" and "systemd-dev"
> kernel memory leaks, potentially exposing race conditions or other more
> serious bug.
>> Maybe, but that sadly is also true for a lot of other known issues, for
>> example those in this quite long list:
>> https://syzkaller.appspot.com/upstream#open
>>
>> It would help if you could pinpoint the problem, then we know who should
>> look into this. You CCed me and the regression list, so I assume it's a
>> regression. Hence: Could you try to bisect it?
>>
>> Ciao, Thorsten

Hi, Thorsten!

I am taking this task, however, it might not be a relatively easy bisect 
like the past
two or three (probably were beginner's luck).

It appears to predate 4.19:

$ head -13 memleak-kwork-4.19.0-08-84df9525b0c2-memlk-menu-al.log
unreferenced object 0xffff8ff917c79c40 (size 16):
   comm "kworker/u12:4", pid 422, jiffies 4294672757 (age 380.342s)
   hex dump (first 16 bytes):
     6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00 memstick0.......
   backtrace:
     [<000000004f7bc99c>] kobject_set_name_vargs+0x1e/0x90
     [<00000000f00ab312>] dev_set_name+0x57/0x70
     [<000000001fd9518e>] memstick_check+0x99/0x330 [memstick]
     [<000000008c797991>] process_one_work+0x1a7/0x3a0
     [<00000000405c5133>] worker_thread+0x30/0x390
     [<0000000060a58c2e>] kthread+0x112/0x130
     [<000000004b138871>] ret_from_fork+0x35/0x40
     [<0000000029f3e0aa>] 0xffffffffffffffff
$

Cheers,
Mirsad

-- 
Mirsad Todorovac
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb
Republic of Croatia, the European Union
--
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu