usbserial: fix inconsistent lock state
In commit acd2a847e7fee7df11817f67dba75a2802793e5d usb_serial_generic_write()
disables interrupts when taking &port->lock which is also taken in
usb_serial_generic_read_bulk_callback() resulting in an inconsistent lock state
due to the latter not disabling interrupts on the local cpu. Fix that by
disabling interrupts in the latter call site also.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 9eb4a65..d415311 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -327,6 +327,7 @@
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
unsigned char *data = urb->transfer_buffer;
int status = urb->status;
+ unsigned long flags;
dbg("%s - port %d", __FUNCTION__, port->number);
@@ -339,11 +340,11 @@
usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
/* Throttle the device if requested by tty */
- spin_lock(&port->lock);
+ spin_lock_irqsave(&port->lock, flags);
if (!(port->throttled = port->throttle_req))
/* Handle data and continue reading from device */
flush_and_resubmit_read_urb(port);
- spin_unlock(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);