From: Felipe Balbi <balbi@xxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 9ec36f7fe20ef919cc15171e1da1b6739222541a upstream. f_phonet's ->set_alt() method will call usb_ep_disable() potentially on an endpoint which is already disabled. That's something the gadget/function driver must guarantee that it's always balanced. In order to balance the calls, just make sure the endpoint was enabled before by means of checking the validity of driver_data. Reported-by: Pali Rohár <pali.rohar@xxxxxxxxx> Signed-off-by: Felipe Balbi <balbi@xxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/usb/gadget/f_phonet.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/f_phonet.c b/drivers/usb/gadget/f_phonet.c index eb3aa817a662..74ff54141416 100644 --- a/drivers/usb/gadget/f_phonet.c +++ b/drivers/usb/gadget/f_phonet.c @@ -417,7 +417,10 @@ static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt) return -EINVAL; spin_lock(&port->lock); - __pn_reset(f); + + if (fp->in_ep->driver_data) + __pn_reset(f); + if (alt == 1) { int i; -- 2.3.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html