hostap_cs_{resume,suspend}(): inconsequent NULL checking

From: Adrian Bunk
Date: Fri Nov 10 2006 - 05:22:32 EST


The Coverity checker spotted the following in
drivers/net/wireless/hostap/hostap_cs.c:

<-- snip -->

...
static int hostap_cs_suspend(struct pcmcia_device *link)
{
struct net_device *dev = (struct net_device *) link->priv;
int dev_open = 0;
struct hostap_interface *iface = NULL;

if (dev)
iface = netdev_priv(dev);

PDEBUG(DEBUG_EXTRA, "%s: CS_EVENT_PM_SUSPEND\n", dev_info);
if (iface && iface->local)
dev_open = iface->local->num_dev_open > 0;
if (dev_open) {
netif_stop_queue(dev);
netif_device_detach(dev);
}
prism2_suspend(dev);

return 0;
}

static int hostap_cs_resume(struct pcmcia_device *link)
{
struct net_device *dev = (struct net_device *) link->priv;
int dev_open = 0;
struct hostap_interface *iface = NULL;

if (dev)
iface = netdev_priv(dev);

PDEBUG(DEBUG_EXTRA, "%s: CS_EVENT_PM_RESUME\n", dev_info);

if (iface && iface->local)
dev_open = iface->local->num_dev_open > 0;

prism2_hw_shutdown(dev, 1);
prism2_hw_config(dev, dev_open ? 0 : 1);
if (dev_open) {
netif_device_attach(dev);
netif_start_queue(dev);
}

return 0;
}
...

<-- snip -->

The problem is that if the "if (dev)" is false, there's a guaranteed
NULL dereference later in the "prism2_suspend(dev)" resp.
"prism2_hw_config(dev, dev_open ? 0 : 1)".

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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