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USB: serial: fix missing locking on fifo in write callback

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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 <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Johan Hovold 2010-03-17 23:00:43 +01:00 committed by Greg Kroah-Hartman
parent 30af7fb5a4
commit 50dbb85287
1 changed files with 5 additions and 2 deletions
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7
drivers/usb/serial/generic.c
View file

@ -519,11 +519,14 @@ 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)
dbg("%s - non-zero urb status: %d", __func__, status);