[PATCH] mt76: mt7921: fix kernel panic by accessing unallocated eeprom.data

[kernel test robot]

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on wireless-next/main]
[also build test WARNING on wireless/main linus/master v6.3-rc6 next-20230406]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/sean-wang-mediatek-com/mt76-mt7921-fix-kernel-panic-by-accessing-unallocated-eeprom-data/20230411-043801
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git main
patch link:    https://lore.kernel.org/r/c9e2a44da4daa00166c802a8c10527359358219d.1681158440.git.objelf%40gmail.com
patch subject: [PATCH] mt76: mt7921: fix kernel panic by accessing unallocated eeprom.data
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230411/202304110556.xbu5H3ka-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/9825ad75cf770d2a15f7008eca476121b9b3d794
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review sean-wang-mediatek-com/mt76-mt7921-fix-kernel-panic-by-accessing-unallocated-eeprom-data/20230411-043801
        git checkout 9825ad75cf770d2a15f7008eca476121b9b3d794
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/net/wireless/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304110556.xbu5H3ka-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/net/wireless/mediatek/mt76/mt7921/mcu.c: In function 'mt7921_mcu_parse_eeprom':
>> drivers/net/wireless/mediatek/mt76/mt7921/mcu.c:22:40: warning: variable 'res' set but not used [-Wunused-but-set-variable]
      22 |         struct mt7921_mcu_eeprom_info *res;
         |                                        ^~~


vim +/res +22 drivers/net/wireless/mediatek/mt76/mt7921/mcu.c

23bdc5d8cadfc9 Ming Yen Hsieh   2022-09-07  18  
1c099ab44727c8 Sean Wang        2021-01-28  19  static int
1c099ab44727c8 Sean Wang        2021-01-28  20  mt7921_mcu_parse_eeprom(struct mt76_dev *dev, struct sk_buff *skb)
1c099ab44727c8 Sean Wang        2021-01-28  21  {
1c099ab44727c8 Sean Wang        2021-01-28 @22  	struct mt7921_mcu_eeprom_info *res;
1c099ab44727c8 Sean Wang        2021-01-28  23  
1c099ab44727c8 Sean Wang        2021-01-28  24  	if (!skb)
1c099ab44727c8 Sean Wang        2021-01-28  25  		return -EINVAL;
1c099ab44727c8 Sean Wang        2021-01-28  26  
fc6ee71a2a8f2d Lorenzo Bianconi 2022-06-20  27  	skb_pull(skb, sizeof(struct mt76_connac2_mcu_rxd));
1c099ab44727c8 Sean Wang        2021-01-28  28  
1c099ab44727c8 Sean Wang        2021-01-28  29  	res = (struct mt7921_mcu_eeprom_info *)skb->data;
1c099ab44727c8 Sean Wang        2021-01-28  30  
1c099ab44727c8 Sean Wang        2021-01-28  31  	return 0;
1c099ab44727c8 Sean Wang        2021-01-28  32  }
1c099ab44727c8 Sean Wang        2021-01-28  33  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests