From aee5da7838787f8ed47f825dbe09e2812acdf97b Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 11 Apr 2017 19:07:29 +0200 Subject: [PATCH] serdev: fix tty-port client deregistration The port client data must be set when registering the serdev controller or client deregistration will fail (and the serdev devices are left registered and allocated) if the port was never opened in between. Make sure to clear the port client data on any probe errors to avoid a use-after-free when the client is later deregistered unconditionally (e.g. in a tty-port deregistration helper). Also move port client operation initialisation to registration. Note that the client ops must be restored on failed probe. Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver") Signed-off-by: Johan Hovold Reviewed-by: Rob Herring Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serdev/serdev-ttyport.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c index 487c88f6aa0e..013efffd2e82 100644 --- a/drivers/tty/serdev/serdev-ttyport.c +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -102,9 +102,6 @@ static int ttyport_open(struct serdev_controller *ctrl) return PTR_ERR(tty); serport->tty = tty; - serport->port->client_ops = &client_ops; - serport->port->client_data = ctrl; - if (tty->ops->open) tty->ops->open(serport->tty, NULL); else @@ -215,6 +212,7 @@ struct device *serdev_tty_port_register(struct tty_port *port, struct device *parent, struct tty_driver *drv, int idx) { + const struct tty_port_client_operations *old_ops; struct serdev_controller *ctrl; struct serport *serport; int ret; @@ -233,15 +231,22 @@ struct device *serdev_tty_port_register(struct tty_port *port, ctrl->ops = &ctrl_ops; + old_ops = port->client_ops; + port->client_ops = &client_ops; + port->client_data = ctrl; + ret = serdev_controller_add(ctrl); if (ret) - goto err_controller_put; + goto err_reset_data; dev_info(&ctrl->dev, "tty port %s%d registered\n", drv->name, idx); return &ctrl->dev; -err_controller_put: +err_reset_data: + port->client_data = NULL; + port->client_ops = old_ops; serdev_controller_put(ctrl); + return ERR_PTR(ret); } -- 2.45.2