Amit Shah <amit.shah@xxxxxxxxxx> writes:
> Between open() being called and processed, the port can be unplugged.
> Check if this happened, and bail out.
>
> A simple test script to reproduce this is:
>
> while true; do for i in $(seq 1 100); do echo $i > /dev/vport0p3; done; done;
>
> This opens and closes the port a lot of times; unplugging the port while
> this is happening triggers the bug.
>
> CC: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
> ---
> 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 291f437..b04ec95 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -1024,6 +1024,10 @@ static int port_fops_open(struct inode *inode, struct file *filp)
>
> /* We get the port with a kref here */
> port = find_port_by_devt(cdev->dev);
> + if (!port) {
> + /* Port was unplugged before we could proceed */
> + return -ENXIO;
> + }
> filp->private_data = port;
>
> /*
> --
> 1.8.1.4
Applied.
Thanks,
Rusty.
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