From: Kees Cook <keescook@chromium.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
syzbot <syzbot+7ffc7214b893651d52b8@syzkaller.appspotmail.com>,
syzkaller-bugs@googlegroups.com,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: WARNING in syscall_exit_to_user_mode
Date: Mon, 14 Sep 2020 13:06:59 -0700 [thread overview]
Message-ID: <202009141304.811BAC4A0@keescook> (raw)
In-Reply-To: <87sgblpi4l.fsf@nanos.tec.linutronix.de>
On Sun, Sep 13, 2020 at 09:54:34PM +0200, Thomas Gleixner wrote:
> On Sat, Sep 12 2020 at 10:52, Kees Cook wrote:
> >> ------------[ cut here ]------------
> >> syscall 56 left IRQs disabled
> >
> > This WARN appears reachable. :)
>
> The above is hardly a problem of the new entry code. It's just detecting
> the wreckage...
Oh, well that's actually even better! :)
> > I also see on the dashboard these other problems with the new entry
> > code:
>
> > https://syzkaller.appspot.com/bug?extid=d4336c84ed0099fdbe47
>
> This one is also just the messenger. That's the
>
> lockdep_assert_irqs_disabled();
>
> in irqentry_exit() if I'm reading the reports correctly. That's a #PF
> returning with interrupts enabled for whatever weird reason. Let me
> stare at that...
Cool; thanks.
> > https://syzkaller.appspot.com/bug?extid=c4af95386364bc59b13e
>
> This one is not a new entry code problem either:
> [...]
> The new entry code is just in the stack trace because that task was
> preempted after a timer interrupt.
This seems a bit like the first issue: it's just getting noticed now?
--
Kees Cook
next prev parent reply other threads:[~2020-09-14 20:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 10:39 WARNING in syscall_exit_to_user_mode syzbot
2020-09-12 17:52 ` Kees Cook
2020-09-13 19:54 ` Thomas Gleixner
2020-09-14 20:06 ` Kees Cook [this message]
2020-09-14 20:22 ` Thomas Gleixner
2020-09-13 19:40 ` Thomas Gleixner
2020-11-08 17:22 ` syzbot
2020-11-11 11:11 ` Dmitry Vyukov
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