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From:   Zhu Yanjun <zyjzyj2000@gmail.com>
Date:   Tue, 23 May 2023 13:08:42 +0800
Message-ID: <CAD=hENdXdqfcxjNrNnP8CoaDy6sUJ4g5uxcWE0mj3HtNohDUzw@mail.gmail.com>
Subject: Re: [syzbot] [rdma?] INFO: trying to register non-static key in
 skb_dequeue (2)
To:     Guoqing Jiang <guoqing.jiang@linux.dev>
Cc:     syzbot <syzbot+eba589d8f49c73d356da@syzkaller.appspotmail.com>,
        jgg@ziepe.ca, leon@kernel.org, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, netdev@vger.kernel.org,
        syzkaller-bugs@googlegroups.com
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On Tue, May 23, 2023 at 12:29=E2=80=AFPM Zhu Yanjun <zyjzyj2000@gmail.com> =
wrote:
>
> On Tue, May 23, 2023 at 12:10=E2=80=AFPM Guoqing Jiang <guoqing.jiang@lin=
ux.dev> wrote:
> >
> >
> >
> > On 5/23/23 12:02, Zhu Yanjun wrote:
> > > On Tue, May 23, 2023 at 11:47=E2=80=AFAM Zhu Yanjun <zyjzyj2000@gmail=
.com> wrote:
> > >> On Tue, May 23, 2023 at 10:26=E2=80=AFAM Guoqing Jiang <guoqing.jian=
g@linux.dev> wrote:
> > >>>
> > >>>
> > >>> On 5/23/23 10:13, syzbot wrote:
> > >>>> Hello,
> > >>>>
> > >>>> syzbot tried to test the proposed patch but the build/boot failed:
> > >>>>
> > >>>> failed to apply patch:
> > >>>> checking file drivers/infiniband/sw/rxe/rxe_qp.c
> > >>>> patch: **** unexpected end of file in patch
> > >> This is not the root cause. The fix is not good.
> > > This problem is about "INFO: trying to register non-static key. The
> > > code is fine but needs lockdep annotation, or maybe"
>
> This warning is from "lock is not initialized". This is a
> use-before-initialized problem.
> The correct fix is to initialize the lock that is complained before it is=
 used.
>
> Zhu Yanjun

Based on the call trace, the followings are the order of this call trace.

291 /* called by the create qp verb */
292 int rxe_qp_from_init(struct rxe_dev *rxe, struct rxe_qp *qp,
struct rxe_pd *pd,
297 {
            ...
317         rxe_qp_init_misc(rxe, qp, init);
            ...
322
323         err =3D rxe_qp_init_resp(rxe, qp, init, udata, uresp);
324         if (err)
325                 goto err2;   <--- error

            ...

334 err2:
335         rxe_queue_cleanup(qp->sq.queue); <--- Goto here
336         qp->sq.queue =3D NULL;

In rxe_qp_init_resp, the error occurs before skb_queue_head_init.
So this call trace appeared.

Zhu Yanjun

> >
> > Which is caused by  "skb_queue_head_init(&qp->resp_pkts)" is not called
> > given rxe_qp_init_resp returns error, but the cleanup still trigger the
> > chain.
> >
> > rxe_qp_do_cleanup -> rxe_completer -> drain_resp_pkts ->
> > skb_dequeue(&qp->resp_pkts)
> >
> > But I might misunderstood it ...
> >
> > Thanks,
> > Guoqing