Use lock to guard against concurrent access for soft-connect/disconnect
operations when writing to soft_connect sysfs.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class")
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
---
Changes in v3:
- Improve flow: avoid assigning "ret = n" early
Changes in v2:
- Consolidate mutex_unlock to a single place using "goto out"
drivers/usb/gadget/udc/core.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 6a62bbd01324..ea114f922ccf 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1529,10 +1529,13 @@ static ssize_t soft_connect_store(struct device *dev,
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")) {
@@ -1543,10 +1546,14 @@ static ssize_t soft_connect_store(struct device *dev,
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);
base-commit: 4e0dcf62ab4cf917d0cbe751b8bf229a065248d4
--
2.28.0
