dereferencing uninitialized variable in anysee_probe()

2010-05-31 Thread Dan Carpenter 
Hi I'm going through some smatch stuff and I had a question.

drivers/media/dvb/dvb-usb/anysee.c +482 anysee_probe(30)
warn: variable dereferenced before check 'd'

   466  ret = dvb_usb_device_init(intf, anysee_properties, 
THIS_MODULE, d,
   467  adapter_nr);

If we're in a cold state then dvb_usb_device_init() can return
zero but d is uninitialized here.

   468  if (ret)
   469  return ret;
   470
   471  alt = usb_altnum_to_altsetting(intf, 0);
   472  if (alt == NULL) {
   473  deb_info(%s: no alt found!\n, __func__);
   474  return -ENODEV;
   475  }
   476
   477  ret = usb_set_interface(d-udev, alt-desc.bInterfaceNumber,
^^^
That would lead to an oops here.

   478  alt-desc.bAlternateSetting);

I'm not sure how to fix this.

regards,
dan carpenter
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Re: dereferencing uninitialized variable in anysee_probe()

2010-05-31 Thread Antti Palosaari 

Terve Dan,

On 05/31/2010 06:09 PM, Dan Carpenter wrote:

Hi I'm going through some smatch stuff and I had a question.

drivers/media/dvb/dvb-usb/anysee.c +482 anysee_probe(30)
warn: variable dereferenced before check 'd'

466  ret = dvb_usb_device_init(intf,anysee_properties, 
THIS_MODULE,d,
467  adapter_nr);

If we're in a cold state then dvb_usb_device_init() can return
zero but d is uninitialized here.


Anysee is always warm. Its USB-bridge, Cypress FX2, uploads firmware 
from eeprom and due to that it is never cold from the drivers point of view.


*cold means device needs firmware upload from driver
*warm means device is ready. Firmware is already uploaded or it is not 
needed at all.



468  if (ret)
469  return ret;
470
471  alt = usb_altnum_to_altsetting(intf, 0);
472  if (alt == NULL) {
473  deb_info(%s: no alt found!\n, __func__);
474  return -ENODEV;
475  }
476
477  ret = usb_set_interface(d-udev, alt-desc.bInterfaceNumber,
 ^^^
That would lead to an oops here.

478  alt-desc.bAlternateSetting);

I'm not sure how to fix this.


After that answer, do you still see problem?

best regards
Antti
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Re: dereferencing uninitialized variable in anysee_probe()

2010-05-31 Thread Dan Carpenter 
On Mon, May 31, 2010 at 06:22:49PM +0300, Antti Palosaari wrote:
 Terve Dan,

 On 05/31/2010 06:09 PM, Dan Carpenter wrote:
 Hi I'm going through some smatch stuff and I had a question.

 drivers/media/dvb/dvb-usb/anysee.c +482 anysee_probe(30)
  warn: variable dereferenced before check 'd'

 466  ret = dvb_usb_device_init(intf,anysee_properties, 
 THIS_MODULE,d,
 467  adapter_nr);

  If we're in a cold state then dvb_usb_device_init() can return
  zero but d is uninitialized here.

 Anysee is always warm. Its USB-bridge, Cypress FX2, uploads firmware  
 from eeprom and due to that it is never cold from the drivers point of 
 view.

 *cold means device needs firmware upload from driver
 *warm means device is ready. Firmware is already uploaded or it is not  
 needed at all.


Wow.  Thanks for the quick response.  I was just auditing the code and
noticed some extra null checking which made me confused.  I'll send a
patch for that.

regards,
dan carpenter
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