Groups > linux.kernel > #1319676

Re: floppy: GPF in floppy_rb0_cb

From	Jiri Kosina <jikos@kernel.org>
Newsgroups	linux.kernel
Subject	Re: floppy: GPF in floppy_rb0_cb
Date	2016-01-27 21:30 +0100
Message-ID	<qVET0-FR-23@gated-at.bofh.it> (permalink)
References	<qUsKe-5k1-15@gated-at.bofh.it> <qUQ0a-54G-17@gated-at.bofh.it> <qURpi-60C-47@gated-at.bofh.it> <qVBBN-6sQ-23@gated-at.bofh.it> <qVBV8-6Sx-19@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, 27 Jan 2016, Dmitry Vyukov wrote:

> > Alright, there is a serious issue with how floppy_revalidate() handles
> > error from lock_fdc() (in-depth explanation for the curious: it doesn't).
> >
> > In case wait_for_event_interruptible() is actually interrupted without
> > succesfully claiming fdc, we proceed with revalidation, causing all kinds
> > of havoc (because another parallel request is still in progress).
> >
> > The whole story with the 'interruptible' parameter to lock_fdc() is funny
> > as well, because we always wait interruptibly anyway. So it can be nuked.
> > Most of the lock_fdc() callsites do properly handle error (and propagate
> > EINTR), but floppy_revalidate() and floppy_check_events() don't.
> >
> > Could you please let syzkaller retest with the patch below? It fixes all
> > the oopses I am able to trigger here.
> 
> Done. I will get back to you if I see any other oops.

Please also get to me in case you don't see any other oops after the 
timeframe you have been able to reproduce the original problem, so that we 
could consider the issue resolved and I can make proper patch from this 
and send it upstream.

Thanks,

-- 
Jiri Kosina
SUSE Labs

Thread

floppy: GPF in floppy_rb0_cb Dmitry Vyukov <dvyukov@google.com> - 2016-01-24 14:20 +0100
  Re: floppy: GPF in floppy_rb0_cb Jiri Kosina <jikos@kernel.org> - 2016-01-25 15:10 +0100
    Re: floppy: GPF in floppy_rb0_cb Dmitry Vyukov <dvyukov@google.com> - 2016-01-25 16:40 +0100
      Re: floppy: GPF in floppy_rb0_cb Jiri Kosina <jikos@kernel.org> - 2016-01-27 18:00 +0100
        Re: floppy: GPF in floppy_rb0_cb Dmitry Vyukov <dvyukov@google.com> - 2016-01-27 18:20 +0100
          Re: floppy: GPF in floppy_rb0_cb Jiri Kosina <jikos@kernel.org> - 2016-01-27 21:30 +0100
            Re: floppy: GPF in floppy_rb0_cb Dmitry Vyukov <dvyukov@google.com> - 2016-01-28 11:40 +0100
              [PATCH] floppy: fix lock_fdc() signal handling Jiri Kosina <jikos@kernel.org> - 2016-01-28 11:50 +0100
                Re: [PATCH] floppy: fix lock_fdc() signal handling Dmitry Vyukov <dvyukov@google.com> - 2016-01-29 10:30 +0100

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