diff options
| author | Oliver Neukum <oneukum@suse.de> | 2013-08-06 14:22:59 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-12 15:41:07 -0700 |
| commit | 6dd433e6cf2475ce8abec1b467720858c24450eb (patch) | |
| tree | fc3359d4bd68a1216835b3ca12221f8632ed602b | |
| parent | e9a088fae5e4f9be729f3f419627abc3886b09de (diff) | |
USB: cdc-wdm: fix race between interrupt handler and tasklet
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>
CC: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 8a230f0ef77..d3318a0df8e 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -209,6 +209,7 @@ 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_cdc_notification *dr; @@ -262,8 +263,8 @@ static void wdm_int_callback(struct urb *urb) 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", @@ -685,16 +686,20 @@ 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); |