Re: [PATCH v4] kobject: Fix global-out-of-bounds in kobject_action_type()

[kernel test robot <lkp@intel.com>]

Hi Xia,

kernel test robot noticed the following build errors:

[auto build test ERROR on driver-core/driver-core-testing]
[also build test ERROR on driver-core/driver-core-next driver-core/driver-core-linus linus/master v6.4-rc1 next-20230512]
[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/Xia-Fukun/kobject-Fix-global-out-of-bounds-in-kobject_action_type/20230512-183414
base:   driver-core/driver-core-testing
patch link:    https://lore.kernel.org/r/20230512103029.183852-1-xiafukun%40huawei.com
patch subject: [PATCH v4] kobject: Fix global-out-of-bounds in kobject_action_type()
config: x86_64-randconfig-a001 (https://download.01.org/0day-ci/archive/20230513/202305130013.em3umwVP-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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/4d1d5546395a3bf45324f25b5e77b90fe6cfe8df
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Xia-Fukun/kobject-Fix-global-out-of-bounds-in-kobject_action_type/20230512-183414
        git checkout 4d1d5546395a3bf45324f25b5e77b90fe6cfe8df
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305130013.em3umwVP-lkp@intel.com/

All errors (new ones prefixed by >>):

>> lib/kobject_uevent.c:90:11: error: implicit declaration of function 'kobject_action' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
           action = kobject_action(i);
                    ^
   lib/kobject_uevent.c:67:9: warning: variable 'count_first' set but not used [-Wunused-but-set-variable]
           size_t count_first;
                  ^
   1 warning and 1 error generated.


vim +/kobject_action +90 lib/kobject_uevent.c

    61	
    62	static int kobject_action_type(const char *buf, size_t count,
    63				       enum kobject_action *type,
    64				       const char **args)
    65	{
    66		enum kobject_action action;
    67		size_t count_first;
    68		const char *args_start;
    69		int i, ret = -EINVAL;
    70	
    71		if (count && (buf[count-1] == '\n' || buf[count-1] == '\0'))
    72			count--;
    73	
    74		if (!count)
    75			goto out;
    76	
    77		args_start = strnchr(buf, count, ' ');
    78		if (args_start) {
    79			count_first = args_start - buf;
    80			args_start = args_start + 1;
    81		} else
    82			count_first = count;
    83	
    84		/* Use sysfs_match_string() to replace the fragile and convoluted loop */
    85		i = sysfs_match_string(kobject_actions, buf);
    86	
    87		if (i < 0)
    88			return ret;
    89	
  > 90		action = kobject_action(i);
    91	
    92		if (args)
    93			*args = args_start;
    94	
    95		*type = action;
    96		ret = 0;
    97	
    98	out:
    99		return ret;
   100	}
   101	

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