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From: Greg KH <gregkh@linuxfoundation.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: peter@hurleysoftware.com, jslaby@suse.com,
	linux-kernel@vger.kernel.org, jslaby@suse.cz,
	andreyknvl@google.com, kcc@google.com, glider@google.com,
	paulmck@linux.vnet.ibm.com, hboehm@google.com
Subject: Re: [PATCH v2] tty: fix data race in flush_to_ldisc
Date: Thu, 17 Sep 2015 05:53:01 -0700	[thread overview]
Message-ID: <20150917125301.GB16085@kroah.com> (raw)
In-Reply-To: <1442486376-115369-1-git-send-email-dvyukov@google.com>

On Thu, Sep 17, 2015 at 12:39:36PM +0200, Dmitry Vyukov wrote:
> flush_to_ldisc reads port->itty and checks that it is not NULL,
> concurrently release_tty sets port->itty to NULL. It is possible
> that flush_to_ldisc loads port->itty once, ensures that it is
> not NULL, but then reloads it again and uses. The second load
> can already return NULL, which will cause a crash.
> 
> Use READ_ONCE to read port->itty.
> 
> The data race was found with KernelThreadSanitizer (KTSAN).
> 
> Signed-off-by: Dmitry Vyukov <dvyukov@google.com>

You sent 3 patches here, but no hint as to what order they need to be
applied in.  Please resend them as a patch series (i.e. 1/3, 2/3, 3/3)
so they can be applied correctly.

thanks,

greg k-h

  reply	other threads:[~2015-09-17 12:53 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-17 10:39 Dmitry Vyukov
2015-09-17 12:53 ` Greg KH [this message]
2015-09-17 13:18   ` Peter Hurley
2015-09-17 13:21     ` Dmitry Vyukov
2015-09-17 13:55       ` Greg KH
2015-09-17 13:54     ` Greg KH

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