From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amit Shah Subject: [PATCH 06/10] virtio: console: fix race in port_fops_poll() and port unplug Date: Fri, 19 Jul 2013 01:46:13 +0530 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: In-Reply-To: References: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Virtualization List Cc: Amit Shah List-Id: virtualization@lists.linuxfoundation.org Between poll() being called and processed, the port can be unplugged. Check if this happened, and bail out. Signed-off-by: Amit Shah --- drivers/char/virtio_console.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7728af9..1d4b748 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -967,6 +967,10 @@ static unsigned int port_fops_poll(struct file *filp, poll_table *wait) unsigned int ret; port = filp->private_data; + if (!port->guest_connected) { + /* Port was unplugged before we could proceed */ + return POLLHUP; + } poll_wait(filp, &port->waitqueue, wait); if (!port->guest_connected) { -- 1.8.1.4