On Wed, Aug 18, 2021 at 12:36:11PM -0600, Shuah Khan wrote: > On 8/17/21 11:39 PM, Greg KH wrote: > > On Tue, Aug 17, 2021 at 05:16:51PM -0600, Shuah Khan wrote: > > > On 8/13/21 12:25 PM, Anirudh Rayabharam wrote: > > > > In vhci_device_unlink_cleanup(), the URBs for unsent unlink requests are > > > > not given back. This sometimes causes usb_kill_urb to wait indefinitely > > > > for that urb to be given back. syzbot has reported a hung task issue [1] > > > > for this. > > > > > > > > To fix this, give back the urbs corresponding to unsent unlink requests > > > > (unlink_tx list) similar to how urbs corresponding to unanswered unlink > > > > requests (unlink_rx list) are given back. > > > > > > > > [1]: https://syzkaller.appspot.com/bug?id=08f12df95ae7da69814e64eb5515d5a85ed06b76 > > > > > > > > Reported-by: syzbot+74d6ef051d3d2eacf428@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > Tested-by: syzbot+74d6ef051d3d2eacf428@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > Signed-off-by: Anirudh Rayabharam <mail@xxxxxxxxxxxxx> > > > > --- > > > > drivers/usb/usbip/vhci_hcd.c | 26 ++++++++++++++++++++++++++ > > > > 1 file changed, 26 insertions(+) > > > > > > > > diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c > > > > index 4ba6bcdaa8e9..6f3f374d4bbc 100644 > > > > --- a/drivers/usb/usbip/vhci_hcd.c > > > > +++ b/drivers/usb/usbip/vhci_hcd.c > > > > @@ -957,8 +957,34 @@ static void vhci_device_unlink_cleanup(struct vhci_device *vdev) > > > > spin_lock(&vdev->priv_lock); > > > > list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) { > > > > + struct urb *urb; > > > > + > > > > + /* give back URB of unsent unlink request */ > > > > pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum); > > > > > > I know this is an exiting one. > > > Let's make this pr_debug or remove it all together. > > > > > > > + > > > > + urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum); > > > > + if (!urb) { > > > > + pr_info("the urb (seqnum %lu) was already given back\n", > > > > + unlink->unlink_seqnum); > > > > > > Let's make this pr_debug or remove it all together. > > > > As you have a struct device for all of these, please use dev_dbg() and > > friends, not pr_*(), for all of these. > > > > Yes. Makes perfect sense. Perhaps we should use usbip_dbg_vhci_hc() instead of dev_dbg()? It is one of the custom macros defined by the usbip driver for printing debug logs. Thanks, Anirudh
