bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

usb: gadget: f_hid: move list and spinlock inits from bind to alloc

Browse Source 
There was an issue when you did the following:
- setup and bind an hid gadget
- open /dev/hidg0
- use the resulting fd in EPOLL_CTL_ADD
- unbind the UDC
- bind the UDC
- use the fd in EPOLL_CTL_DEL

When CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported
within remove_wait_queue (via ep_remove_wait_queue). After some
debugging I found out that the queues, which f_hid registers via
poll_wait were the problem. These were initialized using
init_waitqueue_head inside hidg_bind. So effectively, the bind function
re-initialized the queues while there were still items in them.

The solution is to move the initialization from hidg_bind to hidg_alloc
to extend their lifetimes to the lifetime of the function instance.

Additionally, I found many other possibly problematic init calls in the
bind function, which I moved as well.

Signed-off-by: Michael Zimmermann <sigmaepsilon92@gmail.com>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20260331184844.2388761-1-sigmaepsilon92@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michael Zimmermann
2026-03-31 20:48:44 +02:00
committed by Greg Kroah-Hartman
parent 5abbe6ecc6
commit 4e0a88254a
1 changed files with 10 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/usb/gadget/function/f_hid.c
View File

@@ -1262,17 +1262,8 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
if (status)
goto fail;
spin_lock_init(&hidg->write_spinlock);
hidg->write_pending = 1;
hidg->req = NULL;
spin_lock_init(&hidg->read_spinlock);
spin_lock_init(&hidg->get_report_spinlock);
init_waitqueue_head(&hidg->write_queue);
init_waitqueue_head(&hidg->read_queue);
init_waitqueue_head(&hidg->get_queue);
init_waitqueue_head(&hidg->get_id_queue);
INIT_LIST_HEAD(&hidg->completed_out_req);
INIT_LIST_HEAD(&hidg->report_list);
INIT_WORK(&hidg->work, get_report_workqueue_handler);
hidg->workqueue = alloc_workqueue("report_work",
@@ -1608,6 +1599,16 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
mutex_lock(&opts->lock);
spin_lock_init(&hidg->write_spinlock);
spin_lock_init(&hidg->read_spinlock);
spin_lock_init(&hidg->get_report_spinlock);
init_waitqueue_head(&hidg->write_queue);
init_waitqueue_head(&hidg->read_queue);
init_waitqueue_head(&hidg->get_queue);
init_waitqueue_head(&hidg->get_id_queue);
INIT_LIST_HEAD(&hidg->completed_out_req);
INIT_LIST_HEAD(&hidg->report_list);
device_initialize(&hidg->dev);
hidg->dev.release = hidg_release;
hidg->dev.class = &hidg_class;