Hi Andrei,

On Fri, Mar 21, 2025 at 02:37:26PM +0000, Andrei Kuchynski wrote:

Concurrent calls to typec_partner_unlink_device can lead to a NULL pointer dereference. This patch adds a mutex to protect USB device pointers and prevent this issue. The same mutex protects both the device pointers and the partner device registration.

Cc: stable@vger.kernel.org Fixes: 59de2a56d127 ("usb: typec: Link enumerated USB devices with Type-C partner") Signed-off-by: Andrei Kuchynski akuchynski@chromium.org

Reviewed-by: Benson Leung bleung@chromium.org

---

drivers/usb/typec/class.c | 15 +++++++++++++-- drivers/usb/typec/class.h | 1 + 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c index 9c76c3d0c6cf..eadb150223f8 100644 --- a/drivers/usb/typec/class.c +++ b/drivers/usb/typec/class.c @@ -1052,6 +1052,7 @@ struct typec_partner *typec_register_partner(struct typec_port *port, partner->usb_mode = USB_MODE_USB3; }

• mutex_lock(&port->partner_link_lock); ret = device_register(&partner->dev); if (ret) { dev_err(&port->dev, "failed to register partner (%d)\n", ret);

@@ -1063,6 +1064,7 @@ struct typec_partner *typec_register_partner(struct typec_port *port, typec_partner_link_device(partner, port->usb2_dev); if (port->usb3_dev) typec_partner_link_device(partner, port->usb3_dev);

• mutex_unlock(&port->partner_link_lock);

return partner; } @@ -1083,12 +1085,14 @@ void typec_unregister_partner(struct typec_partner *partner) port = to_typec_port(partner->dev.parent);

• mutex_lock(&port->partner_link_lock); if (port->usb2_dev) typec_partner_unlink_device(partner, port->usb2_dev); if (port->usb3_dev) typec_partner_unlink_device(partner, port->usb3_dev);

device_unregister(&partner->dev);

• mutex_unlock(&port->partner_link_lock);

} EXPORT_SYMBOL_GPL(typec_unregister_partner); @@ -2041,10 +2045,11 @@ static struct typec_partner *typec_get_partner(struct typec_port *port) static void typec_partner_attach(struct typec_connector *con, struct device *dev) { struct typec_port *port = container_of(con, struct typec_port, con);

• struct typec_partner *partner = typec_get_partner(port);

• struct typec_partner *partner; struct usb_device *udev = to_usb_device(dev); enum usb_mode usb_mode;

• mutex_lock(&port->partner_link_lock); if (udev->speed < USB_SPEED_SUPER) { usb_mode = USB_MODE_USB2; port->usb2_dev = dev;

@@ -2053,18 +2058,22 @@ static void typec_partner_attach(struct typec_connector *con, struct device *dev port->usb3_dev = dev; }

• partner = typec_get_partner(port); if (partner) { typec_partner_set_usb_mode(partner, usb_mode); typec_partner_link_device(partner, dev); put_device(&partner->dev); }
• mutex_unlock(&port->partner_link_lock);

} static void typec_partner_deattach(struct typec_connector *con, struct device *dev) { struct typec_port *port = container_of(con, struct typec_port, con);

• struct typec_partner *partner = typec_get_partner(port);

• struct typec_partner *partner;

• mutex_lock(&port->partner_link_lock);
• partner = typec_get_partner(port); if (partner) { typec_partner_unlink_device(partner, dev); put_device(&partner->dev);

@@ -2074,6 +2083,7 @@ static void typec_partner_deattach(struct typec_connector *con, struct device *d port->usb2_dev = NULL; else if (port->usb3_dev == dev) port->usb3_dev = NULL;

• mutex_unlock(&port->partner_link_lock);

} /** @@ -2614,6 +2624,7 @@ struct typec_port *typec_register_port(struct device *parent, ida_init(&port->mode_ids); mutex_init(&port->port_type_lock);

• mutex_init(&port->partner_link_lock);

port->id = id; port->ops = cap->ops; diff --git a/drivers/usb/typec/class.h b/drivers/usb/typec/class.h index b3076a24ad2e..db2fe96c48ff 100644 --- a/drivers/usb/typec/class.h +++ b/drivers/usb/typec/class.h @@ -59,6 +59,7 @@ struct typec_port { enum typec_port_type port_type; enum usb_mode usb_mode; struct mutex port_type_lock;

• struct mutex partner_link_lock;

enum typec_orientation orientation; struct typec_switch *sw; -- 2.49.0.395.g12beb8f557-goog