Re: [PATCH v2 -next] tty: ipwireless: Fix potential NULL pointer dereference

[David Sterba]

On Wed, Jan 30, 2019 at 04:58:30PM +0100, Jiri Slaby wrote:
> On 30. 01. 19, 11:30, YueHaibing wrote:
> > There is a potential NULL pointer dereference in case
> > alloc_ctrl_packet() fails and returns NULL.
> > 
> > Fixes: 099dc4fb6265 ("ipwireless: driver for PC Card 3G/UMTS modem")
> > Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
> > ---
> > v2: fix return value
> > ---
> >  drivers/tty/ipwireless/hardware.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/tty/ipwireless/hardware.c b/drivers/tty/ipwireless/hardware.c
> > index b0baa4c..1e21ae3 100644
> > --- a/drivers/tty/ipwireless/hardware.c
> > +++ b/drivers/tty/ipwireless/hardware.c
> > @@ -1516,6 +1516,8 @@ static void ipw_send_setup_packet(struct ipw_hardware *hw)
> >  			sizeof(struct ipw_setup_get_version_query_packet),
> >  			ADDR_SETUP_PROT, TL_PROTOCOLID_SETUP,
> >  			TL_SETUP_SIGNO_GET_VERSION_QRY);
> > +	if (!ver_packet)
> > +		return;
> 
> LGTM, the timer will retry 30 times, ticking every second.

This should be mentioned in the changelog though, it's not obvious at
all why just returning after a failure is ok and that the packet will be
resent.