linux-usb.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: Shuah Khan <skhan@linuxfoundation.org>
Cc: Anirudh Rayabharam <mail@anirudhrb.com>,
	valentina.manea.m@gmail.com, shuah@kernel.org,
	syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com,
	linux-kernel-mentees@lists.linuxfoundation.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/2] usbip: give back URBs for unsent unlink requests during cleanup
Date: Wed, 18 Aug 2021 07:39:37 +0200	[thread overview]
Message-ID: <YRydGRdPmOaiMWaY@kroah.com> (raw)
In-Reply-To: <13450a85-bbfe-09c5-d614-1a944c2600c2@linuxfoundation.org>

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@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.

As you have a struct device for all of these, please use dev_dbg() and
friends, not pr_*(), for all of these.

thanks,

greg k-h

  reply	other threads:[~2021-08-18  5:39 UTC|newest]

Thread overview: 8+ 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 ` [PATCH v3 1/2] usbip: give back URBs for unsent unlink requests during cleanup Anirudh Rayabharam
2021-08-17 23:16   ` Shuah Khan
2021-08-18  5:39     ` Greg KH [this message]
2021-08-18 18:36       ` Shuah Khan
2021-08-19 18:09         ` Anirudh Rayabharam
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YRydGRdPmOaiMWaY@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=linux-kernel-mentees@lists.linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=mail@anirudhrb.com \
    --cc=shuah@kernel.org \
    --cc=skhan@linuxfoundation.org \
    --cc=syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com \
    --cc=valentina.manea.m@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).