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From: Johan Hovold <johan@kernel.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Johan Hovold <johan@kernel.org>,
	linux-usb@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] USB: serial: digi_acceleport: fix write-wakeup deadlocks
Date: Wed, 4 Nov 2020 11:14:28 +0100	[thread overview]
Message-ID: <20201104101428.GS4085@localhost> (raw)
In-Reply-To: <20201028093818.GB1953863@kroah.com>

On Wed, Oct 28, 2020 at 10:38:18AM +0100, Greg Kroah-Hartman wrote:
> On Mon, Oct 26, 2020 at 11:43:06AM +0100, Johan Hovold wrote:
> > The driver must not call tty_wakeup() while holding its private lock as
> > line disciplines are allowed to call back into write() from
> > write_wakeup(), leading to a deadlock.
> > 
> > Also remove the unneeded work struct that was used to defer wakeup in
> > order to work around a possible race in ancient times (see comment about
> > n_tty write_chan() in commit 14b54e39b412 ("USB: serial: remove
> > changelogs and old todo entries")).
> > 
> > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Johan Hovold <johan@kernel.org>
> > ---
> >  drivers/usb/serial/digi_acceleport.c | 45 ++++++++--------------------
> >  1 file changed, 13 insertions(+), 32 deletions(-)
> 
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks for the review. Applied for -next along with the cleanup patch.

Johan

      reply	other threads:[~2020-11-04 10:14 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26 10:43 [PATCH] USB: serial: digi_acceleport: fix write-wakeup deadlocks Johan Hovold
2020-10-28  9:38 ` Greg KH
2020-11-04 10:14   ` Johan Hovold [this message]

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