In case a race was lost and multiple fds used, an error could be reported multiple times. To fix this a spinlock must be taken. Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> --- drivers/usb/class/cdc-wdm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 1ca2c85a977d..5fb855404403 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -613,7 +613,10 @@ static int wdm_flush(struct file *file, fl_owner_t id) if (!rv) return -EIO; + spin_lock_irq(&desc->iuspin); rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); return usb_translate_errors(rv); } -- 2.16.4
