diff options
| author | Oliver Neukum <oneukum@suse.de> | 2013-08-06 14:22:59 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-26 16:52:46 -0700 |
| commit | fe3efa501f32fc05483a095334573799a954d1ab (patch) | |
| tree | 148d0b7b83e014f1199f3b04fcc64474aa30053e /drivers | |
| parent | 5f8ce0764bb3d54090856cca1c8562c0435003ca (diff) | |
USB: cdc-wdm: fix race between interrupt handler and tasklet
commit 6dd433e6cf2475ce8abec1b467720858c24450eb upstream.
Both could want to submit the same URB. Some checks of the flag
intended to prevent that were missing.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/class/cdc-wdm.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index c84b4553208..0b85e2c7c3d 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -171,6 +171,7 @@ skip_error: static void wdm_int_callback(struct urb *urb) { int rv = 0; + int responding; int status = urb->status; struct wdm_device *desc; struct usb_ctrlrequest *req; @@ -244,8 +245,8 @@ static void wdm_int_callback(struct urb *urb) desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; spin_lock(&desc->iuspin); clear_bit(WDM_READ, &desc->flags); - set_bit(WDM_RESPONDING, &desc->flags); - if (!test_bit(WDM_DISCONNECTING, &desc->flags) + responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); + if (!responding && !test_bit(WDM_DISCONNECTING, &desc->flags) && !test_bit(WDM_SUSPENDING, &desc->flags)) { rv = usb_submit_urb(desc->response, GFP_ATOMIC); dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", @@ -635,16 +636,20 @@ static void wdm_rxwork(struct work_struct *work) { struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); unsigned long flags; - int rv; + int rv = 0; + int responding; spin_lock_irqsave(&desc->iuspin, flags); if (test_bit(WDM_DISCONNECTING, &desc->flags)) { spin_unlock_irqrestore(&desc->iuspin, flags); } else { + responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); spin_unlock_irqrestore(&desc->iuspin, flags); - rv = usb_submit_urb(desc->response, GFP_KERNEL); + if (!responding) + rv = usb_submit_urb(desc->response, GFP_KERNEL); if (rv < 0 && rv != -EPERM) { spin_lock_irqsave(&desc->iuspin, flags); + clear_bit(WDM_RESPONDING, &desc->flags); if (!test_bit(WDM_DISCONNECTING, &desc->flags)) schedule_work(&desc->rxwork); spin_unlock_irqrestore(&desc->iuspin, flags); |