On Thu, Jan 23, 2020 at 05:35:16PM +0100, Steve French wrote:
> On Thu, Jan 23, 2020, 10:17 Vincent Whitchurch <vincent.whitchurch@xxxxxxxx> wrote:
> > This can be reliably reproduced by adding the below delay to
> > cifs_reconnect(), running find(1) on the mount, restarting the samba
> > server while find is running, and killing find during the delay:
> >
> > spin_unlock(&GlobalMid_Lock);
> > mutex_unlock(&server->srv_mutex);
> >
> > + msleep(10000);
> > +
> > cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
> > list_for_each_safe(tmp, tmp2, &retry_list) {
> > mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
> >
> > Fix this by holding a reference to the task struct until the MID is
> > freed.
>
> Cc:stable as well?
Yes, I think this bug has been there for a while.
Note that the test described above usually triggers a different crash on
kernels earlier than v5.4 because abe57073d08c13b95a46ccf48c ("CIFS: Fix
retry mid list corruption on reconnects") has not (yet?) been backported
to those stable kernels.
