Re: [tipc-discussion] BUG: rwlock bad magic on CPU, kworker/0:LINE/NUM, ADDR

[Hoang H. Le <hoa...@de...>]

Hi Jon,

See my inline comment …

Regards,
Hoang
From: Jon Maloy <jm...@re...>
Sent: Wednesday, December 9, 2020 5:22 PM
To: Hoang Huu Le <hoa...@de...>
Cc: tip...@li...; tipc-dek <tip...@de...>
Subject: Fwd: BUG: rwlock bad magic on CPU, kworker/0:LINE/NUM, ADDR

Hi Hoang,
This was the one I had in mind. To me it looks like we still have a problem.

///jon


-------- Forwarded Message --------
Subject:
Re: BUG: rwlock bad magic on CPU, kworker/0:LINE/NUM, ADDR
Date:
Mon, 30 Nov 2020 12:35:30 +0100
From:
Dmitry Vyukov <dv...@go...><mailto:dv...@go...>
To:
syzbot <syz...@sy...><mailto:syz...@sy...>
CC:
David Miller <da...@da...><mailto:da...@da...>, jm...@re...<mailto:jm...@re...>, Jakub Kicinski <ku...@ke...><mailto:ku...@ke...>, LKML <lin...@vg...><mailto:lin...@vg...>, netdev <ne...@vg...><mailto:ne...@vg...>, syzkaller-bugs <syz...@go...><mailto:syz...@go...>, tip...@li...<mailto:tip...@li...>, Ying Xue <yin...@wi...><mailto:yin...@wi...>


On Mon, Nov 30, 2020 at 12:33 PM syzbot
<syz...@sy...><mailto:syz...@sy...> wrote:




Hello,



syzbot found the following issue on:



HEAD commit:    90cf87d1 enetc: Let the hardware auto-advance the taprio b..

git tree:       net

console output: https://syzkaller.appspot.com/x/log.txt?x=135479b3500000

kernel config:  https://syzkaller.appspot.com/x/.config?x=5720c06118e6c4cc

dashboard link: https://syzkaller.appspot.com/bug?extid=cb987a9c796abc570b47

compiler:       gcc (GCC) 10.1.0-syz 20200507



Unfortunately, I don't have any reproducer for this issue yet.



IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syz...@sy...<mailto:syz...@sy...>



tipc: 32-bit node address hash set to aa1414ac

BUG: rwlock bad magic on CPU#0, kworker/0:18/18158, 00000000859f2a8d

CPU: 0 PID: 18158 Comm: kworker/0:18 Not tainted 5.10.0-rc4-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Workqueue: events tipc_net_finalize_work

Call Trace:

 __dump_stack lib/dump_stack.c:77 [inline]

 dump_stack+0x107/0x163 lib/dump_stack.c:118

 rwlock_bug kernel/locking/spinlock_debug.c:144 [inline]

 debug_write_lock_before kernel/locking/spinlock_debug.c:182 [inline]

 do_raw_write_lock+0x1ef/0x280 kernel/locking/spinlock_debug.c:206

 tipc_mon_reinit_self+0x1f7/0x630 net/tipc/monitor.c:685

[Hoang] This is new too me. I will take a look.


There was also "general protection fault in tipc_mon_reinit_self":
https://syzkaller.appspot.com/bug?id=dc141b9a05cb48d3d9b46837bc2fdc9e7d95dbe9
which also happened once. Smells like an intricate race condition.

[Hoang] I guess the race condition already fixed in v5.10.


 tipc_net_finalize net/tipc/net.c:134 [inline]

 tipc_net_finalize+0x1df/0x310 net/tipc/net.c:125

 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272

 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418

 kthread+0x3af/0x4a0 kernel/kthread.c:292

 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296





---

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