Re: [PATCH] isdn: mISDN: Fix potential NULL pointer dereference of kzalloc

[Kangjie Lu]

On 3/2/19 3:26 PM, Gustavo A. R. Silva wrote:
> On 3/2/19 3:20 PM, Aditya Pakki wrote:
> > Allocating memory via kzalloc for phi may fail and causes a
> > NULL pointer dereference. This patch avoids such a scenario.
> Was this detected by Coccinelle?


It was detected by an LLVM-based static analyzer we recently developed.


> If so, please mention it in the commit log.
>
> Thanks
> --
> Gustavo
>
> > Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
> > ---
> >   drivers/isdn/hardware/mISDN/hfcsusb.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
> > index 124ff530da82..26e3182bbca8 100644
> > --- a/drivers/isdn/hardware/mISDN/hfcsusb.c
> > +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
> > @@ -263,6 +263,9 @@ hfcsusb_ph_info(struct hfcsusb *hw)
> >   	int i;
> >   
> >   	phi = kzalloc(struct_size(phi, bch, dch->dev.nrbchan), GFP_ATOMIC);
> > +	if (!phi)
> > +		return;
> > +
> >   	phi->dch.ch.protocol = hw->protocol;
> >   	phi->dch.ch.Flags = dch->Flags;
> >   	phi->dch.state = dch->state;