From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
DRI <dri-devel@lists.freedesktop.org>,
Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
syzbot <syzbot+e84d7ebd1361da13c356@syzkaller.appspotmail.com>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
Thomas Gleixner <tglx@linutronix.de>,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: INFO: trying to register non-static key in try_to_wake_up
Date: Tue, 31 Mar 2020 14:18:30 +0200 [thread overview]
Message-ID: <7641fb29-20ec-0963-d04c-bfbf49fd3ebc@samsung.com> (raw)
In-Reply-To: <CACT4Y+bqBCqDPQZ1Nk8G+8y2vu8aaT2S54J4UqRPaFNUcusbYw@mail.gmail.com>
On 3/31/20 12:18 PM, Dmitry Vyukov wrote:
> On Tue, Mar 31, 2020 at 11:57 AM Peter Zijlstra <peterz@infradead.org> wrote:
>>
>> On Mon, Mar 30, 2020 at 10:01:12PM -0700, syzbot wrote:
>>> Hello,
>>>
>>> syzbot found the following crash on:
>>>
>>> HEAD commit: 9420e8ad Merge tag 'for-linus' of git://git.kernel.org/pub..
>>> git tree: upstream
>>> console output: https://protect2.fireeye.com/url?k=0756a78d-5a9a6c49-07572cc2-0cc47a314e9a-e4dc8b657d340686&u=https://syzkaller.appspot.com/x/log.txt?x=1206ed4be00000
>>> kernel config: https://protect2.fireeye.com/url?k=43211072-1eeddbb6-43209b3d-0cc47a314e9a-3bd45a19932c37c8&u=https://syzkaller.appspot.com/x/.config?x=27392dd2975fd692
>>> dashboard link: https://protect2.fireeye.com/url?k=bf7a6153-e2b6aa97-bf7bea1c-0cc47a314e9a-c64073ee605efb7b&u=https://syzkaller.appspot.com/bug?extid=e84d7ebd1361da13c356
>>> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>>>
>>> Unfortunately, I don't have any reproducer for this crash yet.
>>>
>>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>>> Reported-by: syzbot+e84d7ebd1361da13c356@syzkaller.appspotmail.com
>>>
>>> INFO: trying to register non-static key.
>>> the code is fine but needs lockdep annotation.
>>> turning off the locking correctness validator.
>>> CPU: 1 PID: 1014 Comm: syz-executor.0 Not tainted 5.6.0-rc7-syzkaller #0
>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
>>> Call Trace:
>>> <IRQ>
>>> __dump_stack lib/dump_stack.c:77 [inline]
>>> dump_stack+0x188/0x20d lib/dump_stack.c:118
>>> assign_lock_key kernel/locking/lockdep.c:880 [inline]
>>> register_lock_class+0x14c4/0x1540 kernel/locking/lockdep.c:1189
>>> __lock_acquire+0xfc/0x3ca0 kernel/locking/lockdep.c:3836
>>> lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4484
>>> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
>>> _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159
>>> try_to_wake_up+0x9f/0x17c0 kernel/sched/core.c:2547
>>
>> That's p->pi_lock, which gets initialized in rt_mutex_init_task() in
>> copy_process(). This should be impossible. Very odd.
>
> The stack mentions fbdev, which is a red flag at the moment. There are
> a dozen of bad bugs in fbdev and around. Just few days ago Andy
> pointed to another "impossible" crash "general protection fault in
> do_syscall_64" which is related to dri:
> https://protect2.fireeye.com/url?k=0cb8ad06-517466c2-0cb92649-0cc47a314e9a-a20c11191483c65b&u=https://syzkaller.appspot.com/bug?id=0ec7b2602b1ff40f0d34f38baa4ba1640727c3d9
> https://protect2.fireeye.com/url?k=614292e3-3c8e5927-614319ac-0cc47a314e9a-aeda6d72c01a7b0e&u=https://groups.google.com/forum/#!msg/syzkaller-bugs/ePqhfYx0-8M/Q_Urt97iAAAJ
>
> There are probably more random manifestations of these bugs already,
> and I guess we will be getting more.
>
> +fbdev maintainers
Thank you for the report.
fbdev is in the maintenance mode and no new features or drivers are
being added so syzbot reports are not for a new bugs (regressions) and
are not a priority (at least to me).
I have only resources to review/merge pending fbdev patches from time
to time so any help in fixing these syzbot reports is welcomed (there
have been a few fbdev related syzbot reports recently).
Also please note that fbdev is maintained through drm-misc tree so
patches can also be handled by other drm-misc maintainers in case I'm
not available / busy with other things.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
>>> wake_up_worker kernel/workqueue.c:836 [inline]
>>> insert_work+0x2ad/0x3a0 kernel/workqueue.c:1337
>>> __queue_work+0x50d/0x1280 kernel/workqueue.c:1488
>>> call_timer_fn+0x195/0x760 kernel/time/timer.c:1404
>>> expire_timers kernel/time/timer.c:1444 [inline]
>>> __run_timers kernel/time/timer.c:1773 [inline]
>>> __run_timers kernel/time/timer.c:1740 [inline]
>>> run_timer_softirq+0x412/0x1600 kernel/time/timer.c:1786
>>> __do_softirq+0x26c/0x99d kernel/softirq.c:292
>>> invoke_softirq kernel/softirq.c:373 [inline]
>>> irq_exit+0x192/0x1d0 kernel/softirq.c:413
>>> exiting_irq arch/x86/include/asm/apic.h:546 [inline]
>>> smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1146
>>> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
>>> </IRQ>
next prev parent reply other threads:[~2020-03-31 12:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-31 5:01 INFO: trying to register non-static key in try_to_wake_up syzbot
2020-03-31 9:57 ` Peter Zijlstra
2020-03-31 10:18 ` Dmitry Vyukov
2020-03-31 12:18 ` Bartlomiej Zolnierkiewicz [this message]
2020-03-31 12:50 ` Daniel Vetter
2020-03-31 12:57 ` Daniel Vetter
2020-04-01 8:46 ` Dmitry Vyukov
2020-04-01 8:59 ` Daniel Vetter
2020-04-01 9:06 ` Daniel Vetter
2020-04-03 8:57 ` Dmitry Vyukov
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