From: Amit Shah <amit.shah@redhat.com>
Date: Mon, 29 Jul 2013 04:46:13 +0000 (+0930)
Subject: virtio: console: fix race with port unplug and open/close
X-Git-Tag: v3.11-rc5~25^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=057b82be3ca3d066478e43b162fc082930a746c9;p=pandora-kernel.git

virtio: console: fix race with port unplug and open/close

There's a window between find_port_by_devt() returning a port and us
taking a kref on the port, where the port could get unplugged.  Fix it
by taking the reference in find_port_by_devt() itself.

Problem reported and analyzed by Mateusz Guzik.

CC: <stable@vger.kernel.org>
Reported-by: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---

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