Re: [PATCH] hwmon: it87: describe per-chip temperature resources

[Dan Carpenter <dan.carpenter@linaro.org>]

Hi benoit.masson,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/benoit-masson/hwmon-it87-describe-per-chip-temperature-resources/20251227-043108
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
patch link:    https://lore.kernel.org/r/20251226203021.27244-1-yahoo%40perenite.com
patch subject: [PATCH] hwmon: it87: describe per-chip temperature resources
config: x86_64-randconfig-161-20251229 (https://download.01.org/0day-ci/archive/20251230/202512300415.VRCQoZYs-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202512300415.VRCQoZYs-lkp@intel.com/

smatch warnings:
drivers/hwmon/it87.c:1694 show_pwm_temp_map() warn: variable dereferenced before IS_ERR check 'data' (see line 1691)

vim +/data +1694 drivers/hwmon/it87.c

94ac7ee616809d Jean Delvare   2010-03-05  1685  static ssize_t show_pwm_temp_map(struct device *dev,
94ac7ee616809d Jean Delvare   2010-03-05  1686  				 struct device_attribute *attr, char *buf)
94ac7ee616809d Jean Delvare   2010-03-05  1687  {
94ac7ee616809d Jean Delvare   2010-03-05  1688  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
94ac7ee616809d Jean Delvare   2010-03-05  1689  	struct it87_data *data = it87_update_device(dev);
c962024e306ed5 Guenter Roeck  2015-04-04  1690  	int nr = sensor_attr->index;
542f1e57c17849 benoit.masson  2025-12-26 @1691  	u8 num_map = data->num_temp_map ?: IT87_TEMP_MAP_DEFAULT;
                                                                     ^^^^^^^^^^^^^^^^^^
Unchecked dereference

94ac7ee616809d Jean Delvare   2010-03-05  1692  	int map;
94ac7ee616809d Jean Delvare   2010-03-05  1693  
0282ba4a4fe6c8 Frank Crawford 2023-04-16 @1694  	if (IS_ERR(data))
                                                                   ^^^^
Checked too late.

0282ba4a4fe6c8 Frank Crawford 2023-04-16  1695  		return PTR_ERR(data);
0282ba4a4fe6c8 Frank Crawford 2023-04-16  1696  
0624d861983c2c Guenter Roeck  2015-04-06  1697  	map = data->pwm_temp_map[nr];

-- 
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https://github.com/intel/lkp-tests/wiki