From: Thinh Nguyen Thinh.Nguyen@synopsys.com
commit c28095bc99073ddda65e4f31f6ae0d908d4d5cd8 upstream.
Use lock to guard against concurrent access for soft-connect/disconnect operations when writing to soft_connect sysfs.
Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class") Cc: stable@vger.kernel.org Acked-by: Felipe Balbi balbi@kernel.org Signed-off-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/338ea01fbd69b1985ef58f0f59af02c805ddf189.161061143... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/gadget/udc/core.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
--- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1477,10 +1477,13 @@ static ssize_t soft_connect_store(struct struct device_attribute *attr, const char *buf, size_t n) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); + ssize_t ret;
+ mutex_lock(&udc_lock); if (!udc->driver) { dev_err(dev, "soft-connect without a gadget driver\n"); - return -EOPNOTSUPP; + ret = -EOPNOTSUPP; + goto out; }
if (sysfs_streq(buf, "connect")) { @@ -1491,10 +1494,14 @@ static ssize_t soft_connect_store(struct usb_gadget_udc_stop(udc); } else { dev_err(dev, "unsupported command '%s'\n", buf); - return -EINVAL; + ret = -EINVAL; + goto out; }
- return n; + ret = n; +out: + mutex_unlock(&udc_lock); + return ret; } static DEVICE_ATTR_WO(soft_connect);