This is a note to let you know that I've just added the patch titled
usb: gadget: core: flush gadget workqueue after device removal
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-gadget-core-flush-gadget-workqueue-after-device-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 21c317101fd7537c2d24930480ae0f575af4627d
Author: Roy Luo <royluo@xxxxxxxxxx>
Date: Tue Feb 4 23:36:42 2025 +0000
usb: gadget: core: flush gadget workqueue after device removal
[ Upstream commit 399a45e5237ca14037120b1b895bd38a3b4492ea ]
device_del() can lead to new work being scheduled in gadget->work
workqueue. This is observed, for example, with the dwc3 driver with the
following call stack:
device_del()
gadget_unbind_driver()
usb_gadget_disconnect_locked()
dwc3_gadget_pullup()
dwc3_gadget_soft_disconnect()
usb_gadget_set_state()
schedule_work(&gadget->work)
Move flush_work() after device_del() to ensure the workqueue is cleaned
up.
Fixes: 5702f75375aa9 ("usb: gadget: udc-core: move sysfs_notify() to a workqueue")
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Roy Luo <royluo@xxxxxxxxxx>
Reviewed-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20250204233642.666991-1-royluo@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 1d58adc597a7e..a4120a25428e5 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1538,8 +1538,8 @@ void usb_del_gadget(struct usb_gadget *gadget)
kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
sysfs_remove_link(&udc->dev.kobj, "gadget");
- flush_work(&gadget->work);
device_del(&gadget->dev);
+ flush_work(&gadget->work);
ida_free(&gadget_id_numbers, gadget->id_number);
cancel_work_sync(&udc->vbus_work);
device_unregister(&udc->dev);
