Re: [PATCH] infiniband: cxgb4: fix a potential NULL pointer dereference

[Jason Gunthorpe]

On Wed, Mar 27, 2019 at 07:08:54PM +0530, Potnuri Bharat Teja wrote:
> On Saturday, March 03/23/19, 2019 at 08:07:46 +0530, Kangjie Lu wrote:
> > 
> > 
> > > On Mar 8, 2019, at 11:19 PM, Kangjie Lu <kjlu@xxxxxxx> wrote:
> > > 
> > > get_skb may fail and return NULL. The fix returns "ENOMEM"
> > > when it fails to avoid NULL dereference.
> > > 
> > > Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
> > > drivers/infiniband/hw/cxgb4/cm.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> > > index 8221813219e5..502a54d57e2c 100644
> > > +++ b/drivers/infiniband/hw/cxgb4/cm.c
> > > @@ -1919,6 +1919,9 @@ static int send_fw_act_open_req(struct c4iw_ep *ep, unsigned int atid)
> > > 	int win;
> > > 
> > > 	skb = get_skb(NULL, sizeof(*req), GFP_KERNEL);
> > > +	if (!skb)
> > > +		return -ENOMEM;
> > > +
> > 
> > Can someone review this patch? Thanks.
> 
> Sorry for the late response.
> I recommend an error print before the return.
> if (!skb) {
> 	pr_err("%s - failed to alloc skb\n", __func__);
> 	return -ENOMEM;
> }

no error prints on memory allocation failure, the kernel already
prints enough on this

Jason