Patch "USB: serial: console: fix uninitialised spinlock" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

USB: serial: console: fix uninitialised spinlock

to the 4.9-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-serial-console-fix-uninitialised-spinlock.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Johan Hovold <[email protected]>
Date: Wed, 8 Feb 2017 18:53:08 +0100
Subject: USB: serial: console: fix uninitialised spinlock

From: Johan Hovold <[email protected]>

commit 14816b16fa0adac24f82492f18fa62c55acabbbe upstream.

Since commit 4a510969374a ("tty: Make tty_files_lock per-tty") a new tty_struct spin lock is taken in the tty release path, but the USB-serial-console hack was never updated hence leaving the lock of its "fake" tty uninitialised. This was eventually detected by lockdep.

Make sure to initialise the new lock also for the fake tty to address this regression.

Yes, this code is a mess, but cleaning it up is left for another day.

---
 drivers/usb/serial/console.c |    1 +
 1 file changed, 1 insertion(+)

@@ -143,6 +143,7 @@ static int usb_console_setup(struct cons
 			tty->driver = usb_serial_tty_driver;
 			tty->index = co->index;
 			init_ldsem(&tty->ldisc_sem);
+			spin_lock_init(&tty->files_lock);
 			INIT_LIST_HEAD(&tty->tty_files);
 			kref_get(&tty->driver->kref);
 			__module_get(tty->driver->owner);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/usb-serial-ftdi_sio-fix-modem-status-error-handling.patch queue-4.9/usb-serial-cp210x-add-new-ids-for-ge-bx50v3-boards.patch queue-4.9/usb-serial-ark3116-fix-register-accessor-error-handling.patch queue-4.9/usb-serial-digi_acceleport-fix-oob-data-sanity-check.patch queue-4.9/usb-serial-ftdi_sio-fix-line-status-over-reporting.patch queue-4.9/usb-serial-ftdi_sio-fix-extreme-low-latency-setting.patch queue-4.9/usb-serial-spcp8x5-fix-modem-status-handling.patch queue-4.9/usb-serial-opticon-fix-cts-retrieval-at-open.patch queue-4.9/usb-serial-mos7840-fix-another-null-deref-at-open.patch queue-4.9/usb-serial-console-fix-uninitialised-spinlock.patch