From: Peter Chen <peter.chen@nxp.com>
To: hui yang <yanghui.def@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
"balbi@kernel.org" <balbi@kernel.org>,
"mirq-linux@rere.qmqm.pl" <mirq-linux@rere.qmqm.pl>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] USB(u_serial.c): it has a NULL point
Date: Wed, 13 Nov 2019 07:13:38 +0000 [thread overview]
Message-ID: <20191113071558.GB30608@b29397-desktop> (raw)
In-Reply-To: <CA+wXOo2nzANnbfFA6mHa3ZQxyA6bYgL9CM3Ykq12m_rxkRyQ4Q@mail.gmail.com>
On 19-11-09 15:49:13, hui yang wrote:
> I'm sorry for my fault . Now I send to everyone .
>
> When we use USB to transmit data
> with PC, the phone will crashed Low probability .
> We found port->port.tty became NULL.
Would you please debug more, it seems gs open/close (gs_open/gs_close)
are something wrong. The value port->port.tty and port->port.count
are inconsistent.
Peter
>
> Thanks
>
> Greg KH <gregkh@linuxfoundation.org> 于2019年11月3日周日 下午8:42写道:
> >
> > On Sun, Nov 03, 2019 at 10:44:04AM +0800, hui yang wrote:
> > > From: YangHui <yanghui.def@gmail.com>
> > >
> > > Unable to handle kernel NULL pointer dereference at virtual address 000002a0
> > > Kernel BUG at tty_wakeup+0x18/0x8c
> > > [<0000000095135e9d>] tty_wakeup+0x18/0x8c
> > > [<00000000c35f19e4>] gs_start_io+0xc8/0x158
> > > [<00000000b11b184e>] gserial_connect+0xd0/0x174
> > > [<00000000642201de>] acm_set_alt+0x70/0x180
> > > [<00000000a9d38e8b>] composite_setup+0x1848/0x1a7c
> > > [<0000000072c88781>] android_setup+0x1ec/0x1f4
> > > [<000000004c0127a5>] msm_udc_irq+0x8d0/0xc0c
> > > [<00000000f8bb9acf>] __handle_irq_event_percpu+0x74/0x294
> > > [<00000000afd57256>] handle_irq_event+0x60/0xc8
> > > [<0000000076719b24>] handle_fasteoi_irq+0xc8/0x1c4
> > > [<00000000421f3d87>] generic_handle_irq+0x34/0x4c
> > > [<00000000b2f2d343>] __handle_domain_irq+0x6c/0xbc
> > > [<00000000c74325e8>] gic_handle_irq+0x6c/0xe0
> > > yes,we can see the port->port.tty==NULL, so system crashed
> > >
> > > Signed-off-by: YangHui <yanghui.def@gmail.com>
> > > ---
> > > drivers/usb/gadget/function/u_serial.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
> > > index 65f634e..a1c2ac2 100644
> > > --- a/drivers/usb/gadget/function/u_serial.c
> > > +++ b/drivers/usb/gadget/function/u_serial.c
> > > @@ -562,6 +562,8 @@ static int gs_start_io(struct gs_port *port)
> > >
> > > /* unblock any pending writes into our circular buffer */
> > > if (started) {
> > > + if (port->port.tty == NULL)
> > > + return -EIO;
> >
> > How can this happen? Shouldn't this be handled earlier?
> >
> > If not, can you document this how this can be true and what should be
> > done about it?
> >
> > thanks,
> >
> > greg k-h
--
Thanks,
Peter Chen
next prev parent reply other threads:[~2019-11-13 7:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-03 2:44 [PATCH 2/2] USB(u_serial.c): it has a NULL point hui yang
2019-11-03 12:42 ` Greg KH
2019-11-09 7:49 ` hui yang
2019-11-13 7:13 ` Peter Chen [this message]
[not found] <5dbeddab.1c69fb81.244fa.5f8c@mx.google.com>
2019-11-03 14:16 ` Greg KH
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