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Message-Id: <20211129181712.127984401@linuxfoundation.org>
Date: Mon, 29 Nov 2021 19:17:25 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org,
Marek Szyprowski <m.szyprowski@...sung.com>,
Hans de Goede <hdegoede@...hat.com>,
Mathias Nyman <mathias.nyman@...ux.intel.com>
Subject: [PATCH 5.10 014/121] usb: hub: Fix locking issues with address0_mutex
From: Mathias Nyman <mathias.nyman@...ux.intel.com>
commit 6cca13de26eea6d32a98d96d916a048d16a12822 upstream.
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: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race")
Cc: <stable@...r.kernel.org>
Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
Tested-by: Hans de Goede <hdegoede@...hat.com>
Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>
Acked-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: Mathias Nyman <mathias.nyman@...ux.intel.com>
Link: https://lore.kernel.org/r/20211123101656.1113518-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
drivers/usb/core/hub.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5112,6 +5112,7 @@ static void hub_port_connect(struct usb_
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) {
@@ -5168,10 +5169,10 @@ static void hub_port_connect(struct usb_
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
*/
@@ -5179,6 +5180,8 @@ static void hub_port_connect(struct usb_
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;
}
@@ -5200,13 +5203,13 @@ static void hub_port_connect(struct usb_
}
/* 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);
@@ -5296,11 +5299,14 @@ static void hub_port_connect(struct usb_
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;
@@ -5323,8 +5329,6 @@ loop:
}
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)
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