Re: [CHECKER] 54 missing null pointer checks in 2.4.17

[Dawson Engler <engler@csl.Stanford.EDU>]

> > [BUG] (synonums aren't working)
> > /u2/engler/mc/oses/linux/2.4.17/drivers/net/eexpress.c:1088:eexp_hw_probe:
> > ERROR:NULL:1083:1088:Using ptr "lp" illegally! set by 'kmalloc':1083
> > [COUNTER=kmalloc:1083] [fit=1] [fit_fn=5] [fn_ex=0] [fn_counter=1]
> > [ex=1399] [counter=26] [z = 5.50002098543802] [fn-z = -4.35889894354067]
> >                 }
> > 
> >                 buswidth = !((setupval & 0x400) >> 10);
> >         }
> > 
> > Start --->
> >         dev->priv = lp = kmalloc(sizeof(struct net_local), GFP_KERNEL);
> >         if (!dev->priv)
> >                 return -ENOMEM;
> > 
> >         memset(dev->priv, 0, sizeof(struct net_local));
> > Error --->
> >         spin_lock_init(&lp->lock);
> 
> This one isn't a bug. The pointer to allocated memory is stored in two
> variables. Only one of them is verified against NULL, that is enough.


Yuck.  Sorry about that --- I mislabeled the message.  It's a BUG,
but in our system rather than in 2.4.17.  Bug finding still tends
to be unfortunately symetrical...