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

[Jon M. <jm...@re...>]

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...>
To: 	syzbot <syz...@sy...>
CC: 	David Miller <da...@da...>, jm...@re..., Jakub 
Kicinski <ku...@ke...>, LKML <lin...@vg...>, netdev 
<ne...@vg...>, syzkaller-bugs 
<syz...@go...>, 
tip...@li..., Ying Xue <yin...@wi...>



On Mon, Nov 30, 2020 at 12:33 PM syzbot
<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...
>
> 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

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.


>   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
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syz...@go....
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syz...@go....
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000004e5bdb05b5516009%40google.com.