patch "usb: hub: Fix locking issues with address0_mutex" added to usb-linus
Subsystems (2)
This is a note to let you know that I've just added the patch titled
usb: hub: Fix locking issues with address0_mutex
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 6cca13de26eea6d32a98d96d916a048d16a12822 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <[email protected]>
Date: Tue, 23 Nov 2021 12:16:56 +0200
Subject: 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
--- drivers/usb/core/hub.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
drivers/usb/core/hub.c +12 -8
@@ -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 )
Signature · 1 line
2.34.0