Commit 6cca13de authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman

usb: hub: Fix locking issues with address0_mutex

Fix the circular lock dependency and unbalanced unlock of addess0_mutex
introduced when fixing an address0_mutex enumeration retry race in commit
ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race")

Make sure locking order between port_dev->status_lock and address0_mutex
is correct, and that address0_mutex is not unlocked in hub_port_connect
"done:" codepath which may be reached without locking address0_mutex

Fixes: 6ae6dc22 ("usb: hub: Fix usb enumeration issue due to address0 race")
Cc: <stable@vger.kernel.org>
Reported-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: default avatarHans de Goede <hdegoede@redhat.com>
Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20211123101656.1113518-1-mathias.nyman@linux.intel.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d4d2e532
......@@ -5188,6 +5188,7 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
struct usb_port *port_dev = hub->ports[port1 - 1];
struct usb_device *udev = port_dev->child;
static int unreliable_port = -1;
bool retry_locked;
/* Disconnect any existing devices under this port */
if (udev) {
......@@ -5244,10 +5245,10 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
status = 0;
mutex_lock(hcd->address0_mutex);
for (i = 0; i < PORT_INIT_TRIES; i++) {
usb_lock_port(port_dev);
mutex_lock(hcd->address0_mutex);
retry_locked = true;
/* reallocate for each attempt, since references
* to the previous one can escape in various ways
*/
......@@ -5255,6 +5256,8 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
if (!udev) {
dev_err(&port_dev->dev,
"couldn't allocate usb_device\n");
mutex_unlock(hcd->address0_mutex);
usb_unlock_port(port_dev);
goto done;
}
......@@ -5276,13 +5279,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
}
/* reset (non-USB 3.0 devices) and get descriptor */
usb_lock_port(port_dev);
status = hub_port_init(hub, udev, port1, i);
usb_unlock_port(port_dev);
if (status < 0)
goto loop;
mutex_unlock(hcd->address0_mutex);
usb_unlock_port(port_dev);
retry_locked = false;
if (udev->quirks & USB_QUIRK_DELAY_INIT)
msleep(2000);
......@@ -5372,11 +5375,14 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
loop_disable:
hub_port_disable(hub, port1, 1);
mutex_lock(hcd->address0_mutex);
loop:
usb_ep0_reinit(udev);
release_devnum(udev);
hub_free_dev(udev);
if (retry_locked) {
mutex_unlock(hcd->address0_mutex);
usb_unlock_port(port_dev);
}
usb_put_dev(udev);
if ((status == -ENOTCONN) || (status == -ENOTSUPP))
break;
......@@ -5399,8 +5405,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
}
done:
mutex_unlock(hcd->address0_mutex);
hub_port_disable(hub, port1, 1);
if (hcd->driver->relinquish_port && !hub->hdev->parent) {
if (status != -ENOTCONN && status != -ENODEV)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment