This is a note to let you know that I've just added the patch titled
serdev: ttyport: fix tty locking in close
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: serdev-ttyport-fix-tty-locking-in-close.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 90dbad8cd6efccbdce109d5ef0724f8434a6cdde Mon Sep 17 00:00:00 2001
From: Johan Hovold johan@kernel.org Date: Fri, 3 Nov 2017 15:30:56 +0100 Subject: serdev: ttyport: fix tty locking in close
From: Johan Hovold johan@kernel.org
commit 90dbad8cd6efccbdce109d5ef0724f8434a6cdde upstream.
Make sure to hold the tty lock as required when calling tty-driver close() (e.g. to avoid racing with hangup()).
Note that the serport active flag is currently set under the lock at controller open, but really isn't protected by it.
Fixes: cd6484e1830b ("serdev: Introduce new bus for serial attached devices") Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serdev/serdev-ttyport.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/tty/serdev/serdev-ttyport.c +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -149,8 +149,10 @@ static void ttyport_close(struct serdev_
clear_bit(SERPORT_ACTIVE, &serport->flags);
+ tty_lock(tty); if (tty->ops->close) tty->ops->close(tty, NULL); + tty_unlock(tty);
tty_release_struct(tty, serport->tty_idx); }
Patches currently in stable-queue which might be from johan@kernel.org are
queue-4.14/serdev-ttyport-fix-null-deref-on-hangup.patch queue-4.14/serdev-ttyport-fix-tty-locking-in-close.patch queue-4.14/serdev-ttyport-add-missing-receive_buf-sanity-checks.patch