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Commit bfaeafcf authored by Borislav Petkov's avatar Borislav Petkov Committed by Greg Kroah-Hartman
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usbserial: fix inconsistent lock state 



In commit acd2a847 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: default avatarBorislav Petkov <bbpetkov@yahoo.de>
Acked-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ed206ec9

drivers/usb/serial/generic.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -327,6 +327,7 @@ void usb_serial_generic_read_bulk_callback (struct urb *urb) 
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;

	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;

	unsigned char *data = urb->transfer_buffer;

	unsigned char *data = urb->transfer_buffer;

	int status = urb->status;

	int status = urb->status;

	unsigned long flags;





	dbg("%s - port %d", __FUNCTION__, port->number);

	dbg("%s - port %d", __FUNCTION__, port->number);
@@ -339,11 +340,11 @@ void usb_serial_generic_read_bulk_callback (struct urb *urb) 
	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);





	/* Throttle the device if requested by tty */

	/* Throttle the device if requested by tty */

	spin_lock(&port->lock);

	spin_lock_irqsave(&port->lock, flags);

	if (!(port->throttled = port->throttle_req))

	if (!(port->throttled = port->throttle_req))

		/* Handle data and continue reading from device */

		/* Handle data and continue reading from device */

		flush_and_resubmit_read_urb(port);

		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);

EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);