Apologies resent V1 again instead of V2. Have sent V2 for real.
On Wed, Apr 5, 2023 at 11:19 PM Badhri Jagan Sridharan badhri@google.com wrote:
usb_udc_connect_control does not check to see if the udc has already been started. This causes gadget->ops->pullup to be called through usb_gadget_connect when invoked from usb_udc_vbus_handler even before usb_gadget_udc_start is called. Guard this by checking for udc->started in usb_udc_connect_control before invoking usb_gadget_connect.
Guarding udc_connect_control, udc->started and udc->vbus with its own mutex as usb_udc_connect_control_locked can be simulataneously invoked from different code paths.
Cc: stable@vger.kernel.org
Signed-off-by: Badhri Jagan Sridharan badhri@google.com Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler")
drivers/usb/gadget/udc/core.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 3dcbba739db6..890f92cb6344 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -56,6 +56,8 @@ static LIST_HEAD(udc_list); /* Protects udc_list, udc->driver, driver->is_bound, and related calls */ static DEFINE_MUTEX(udc_lock);
+/* Protects udc->vbus, udc-started and udc_connect_control_locked */ +static DEFINE_MUTEX(udc_connect_control_lock); /* ------------------------------------------------------------------------- */
/** @@ -1078,9 +1080,10 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state);
/* ------------------------------------------------------------------------- */
-static void usb_udc_connect_control(struct usb_udc *udc) +/* Acquire udc_connect_control_lock before calling this function. */ +static void usb_udc_connect_control_locked(struct usb_udc *udc) {
if (udc->vbus)
if (udc->vbus && udc->started) usb_gadget_connect(udc->gadget); else usb_gadget_disconnect(udc->gadget);@@ -1099,10 +1102,12 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) { struct usb_udc *udc = gadget->udc;
mutex_lock(&udc_connect_control_lock); if (udc) { udc->vbus = status;
usb_udc_connect_control(udc);
usb_udc_connect_control_locked(udc); }mutex_unlock(&udc_connect_control_lock);} EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
@@ -1140,14 +1145,18 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) { int ret;
mutex_lock(&udc_connect_control_lock); if (udc->started) { dev_err(&udc->dev, "UDC had already started\n");mutex_unlock(&udc_connect_control_lock); return -EBUSY; } ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver); if (!ret) udc->started = true;usb_udc_connect_control_locked(udc);mutex_unlock(&udc_connect_control_lock); return ret;} @@ -1165,13 +1174,17 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) */ static inline void usb_gadget_udc_stop(struct usb_udc *udc) {
mutex_lock(&udc_connect_control_lock); if (!udc->started) { dev_err(&udc->dev, "UDC had already stopped\n");mutex_unlock(&udc_connect_control_lock); return; } udc->gadget->ops->udc_stop(udc->gadget); udc->started = false;usb_udc_connect_control_locked(udc);mutex_unlock(&udc_connect_control_lock);}
/** @@ -1527,7 +1540,6 @@ static int gadget_bind_driver(struct device *dev) if (ret) goto err_start; usb_gadget_enable_async_callbacks(udc);
usb_udc_connect_control(udc); kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); return 0;base-commit: d629c0e221cd99198b843d8351a0a9bfec6c0423
2.40.0.348.gf938b09366-goog