On Mon, 2023-05-22 at 11:19 +0530, Prashanth K wrote:
> External email : Please do not click links or open attachments until
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>
> On 22-05-23 07:51 am, Chunfeng Yun wrote:
> > When gserial_disconnect has already cleared gser->ioport, and the
> > suspend triggers afterwards, gserial_suspend gets called, which
> > will
> > lead to accessing of gser->ioport and thus causing null pointer
> > dereference. Add a null pointer check to prevent it as the bellow
> > patch does:
> > 5ec63fdbca60 ("usb: gadget: u_serial: Add null pointer check in
> > gserial_resume")
> >
> > Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume
> > callbacks")
> > Cc: stable <stable@xxxxxxxxxx>
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > ---
> > drivers/usb/gadget/function/u_serial.c | 12 ++++++++++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/gadget/function/u_serial.c
> > b/drivers/usb/gadget/function/u_serial.c
> > index a0ca47fbff0f..40ba220cf6d2 100644
> > --- a/drivers/usb/gadget/function/u_serial.c
> > +++ b/drivers/usb/gadget/function/u_serial.c
> > @@ -1420,10 +1420,18 @@ EXPORT_SYMBOL_GPL(gserial_disconnect);
> >
> > void gserial_suspend(struct gserial *gser)
> > {
> > - struct gs_port *port = gser->ioport;
> > + struct gs_port *port;
> > unsigned long flags;
> >
> > - spin_lock_irqsave(&port->port_lock, flags);
> > + spin_lock_irqsave(&serial_port_lock, flags);
> > + port = gser->ioport;
> > + if (!port) {
> > + spin_unlock_irqrestore(&serial_port_lock, flags);
> > + return;
> > + }
> > +
> > + spin_lock(&port->port_lock);
> > + spin_unlock(&serial_port_lock);
> > port->suspended = true;
> > spin_unlock_irqrestore(&port->port_lock, flags);
> > }
>
> Hi Chunfeng,
>
> This looks same as the following patch.
>
https://lore.kernel.org/linux-usb/1683278317-11774-1-git-send-email-quic_prashk@xxxxxxxxxxx/
Yes, it is, please ignore this one, thanks a lot
>
>
> Regards
