Re: [PATCH] USB: cdc-wdm: Fix ODEBUG bug in wdm_disconnect

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, May 11, 2021 at 10:11:41AM +0200, Oliver Neukum wrote:
> Am Dienstag, den 11.05.2021, 14:48 +0900 schrieb Tetsuo Handa:
> > On 2021/05/11 12:31, qiang.zhang@windriver.com wrote:
> > > This warning is generated because when kfree wdm_device,
> > > it is found that there is still an active work in workqueue,
> > > This phenomenon may be due to the following reasons.
> > > when the devices disconnect, although the work was cancelled,
> > > but the schedule_work still may be called, therefore, before
> > > scheduling work, we need to detect the status of the device.
> > > 
> > > Reported-by: syzbot <
> > > syzbot+7da71853830ac3289474@syzkaller.appspotmail.com>
> > > Signed-off-by: Zqiang <qiang.zhang@windriver.com>
> > > ---
> > >  drivers/usb/class/cdc-wdm.c | 13 ++++++++-----
> > >  1 file changed, 8 insertions(+), 5 deletions(-)
> > > 
> > 
> > Oliver Neukum is aware of this problem, and is considering poisoning
> > approach than
> > checking WDM_SUSPENDING/WDM_RESETTING/WDM_DISCONNECTING approach. I
> > guess we could
> > replace three test_bit() tests into OR'ed-bits test (something like
> > test_bits()) ?
> > 
> >   
> > https://lkml.kernel.org/r/2db36d52015b644cc1891fcffc87ef09c2b728b7.camel@suse.com
> > 
> > Oliver, how do we want to fix this problem?
> 
> Hi,
> 
> I was under the assumption that Greg had already merged the fix
> 18abf874367456540846319574864e6ff32752e2
> Am I wrong?

That is in my usb-linus branch and is not in Linus's tree yet.  Give it
a week or so to get there...

thanks,

greg k-h