From 50dbb8528757b1977efd5d270ed9d262cbbef87d Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 17 Mar 2010 23:00:43 +0100 Subject: [PATCH] USB: serial: fix missing locking on fifo in write callback On errors the fifo was reset without any locking. This could race with write which do kfifo_put and perhaps also chars_in_buffer and write_room. Every other access to the fifo is protected using the port lock so better add it to the error path as well. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/generic.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 8f78d7b8e88..2a3196a2c66 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -519,10 +519,13 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb) port->write_urb_busy = 0; spin_unlock_irqrestore(&port->lock, flags); - if (status) + if (status) { + spin_lock_irqsave(&port->lock, flags); kfifo_reset_out(&port->write_fifo); - else + spin_unlock_irqrestore(&port->lock, flags); + } else { usb_serial_generic_write_start(port); + } } if (status) -- 2.20.1