From: Shuah Khan <skhan@linuxfoundation.org> To: Anirudh Rayabharam <mail@anirudhrb.com>, valentina.manea.m@gmail.com, shuah@kernel.org, gregkh@linuxfoundation.org Cc: syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com, linux-kernel-mentees@lists.linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan <skhan@linuxfoundation.org> Subject: Re: [PATCH v3 1/2] usbip: give back URBs for unsent unlink requests during cleanup Date: Tue, 17 Aug 2021 17:16:51 -0600 [thread overview] Message-ID: <13450a85-bbfe-09c5-d614-1a944c2600c2@linuxfoundation.org> (raw) In-Reply-To: <20210813182508.28127-2-mail@anirudhrb.com> 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@syzkaller.appspotmail.com > Tested-by: syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com > Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com> > --- > 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. > + list_del(&unlink->list); > + kfree(unlink); > + continue; > + } > + > + urb->status = -ENODEV; > + > + usb_hcd_unlink_urb_from_ep(hcd, urb); > + > list_del(&unlink->list); > + > + spin_unlock(&vdev->priv_lock); > + spin_unlock_irqrestore(&vhci->lock, flags); > + > + usb_hcd_giveback_urb(hcd, urb, urb->status); > + > + spin_lock_irqsave(&vhci->lock, flags); > + spin_lock(&vdev->priv_lock); > + > kfree(unlink); > } > > thanks, -- Shuah
WARNING: multiple messages have this Message-ID (diff)
From: Shuah Khan <skhan@linuxfoundation.org> To: Anirudh Rayabharam <mail@anirudhrb.com>, valentina.manea.m@gmail.com, shuah@kernel.org, gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org, syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com Subject: Re: [PATCH v3 1/2] usbip: give back URBs for unsent unlink requests during cleanup Date: Tue, 17 Aug 2021 17:16:51 -0600 [thread overview] Message-ID: <13450a85-bbfe-09c5-d614-1a944c2600c2@linuxfoundation.org> (raw) In-Reply-To: <20210813182508.28127-2-mail@anirudhrb.com> 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@syzkaller.appspotmail.com > Tested-by: syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com > Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com> > --- > 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. > + list_del(&unlink->list); > + kfree(unlink); > + continue; > + } > + > + urb->status = -ENODEV; > + > + usb_hcd_unlink_urb_from_ep(hcd, urb); > + > list_del(&unlink->list); > + > + spin_unlock(&vdev->priv_lock); > + spin_unlock_irqrestore(&vhci->lock, flags); > + > + usb_hcd_giveback_urb(hcd, urb, urb->status); > + > + spin_lock_irqsave(&vhci->lock, flags); > + spin_lock(&vdev->priv_lock); > + > kfree(unlink); > } > > thanks, -- Shuah _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
next prev parent reply other threads:[~2021-08-17 23:16 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-13 18:25 [PATCH v3 0/2] Fix syzkaller bug: hung task in hub_port_init Anirudh Rayabharam 2021-08-13 18:25 ` Anirudh Rayabharam 2021-08-13 18:25 ` [PATCH v3 1/2] usbip: give back URBs for unsent unlink requests during cleanup Anirudh Rayabharam 2021-08-13 18:25 ` Anirudh Rayabharam 2021-08-17 23:16 ` Shuah Khan [this message] 2021-08-17 23:16 ` Shuah Khan 2021-08-18 5:39 ` Greg KH 2021-08-18 5:39 ` Greg KH 2021-08-18 18:36 ` Shuah Khan 2021-08-18 18:36 ` Shuah Khan 2021-08-19 18:09 ` Anirudh Rayabharam 2021-08-19 18:09 ` Anirudh Rayabharam 2021-08-19 18:49 ` Shuah Khan 2021-08-19 18:49 ` Shuah Khan 2021-08-13 18:25 ` [PATCH v3 2/2] usbip: eliminate duplicate code in vhci_device_unlink_cleanup Anirudh Rayabharam 2021-08-13 18:25 ` Anirudh Rayabharam
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