• Kees Cook's avatar
    hwmon: (pc87360) Bounds check data->innr usage · 4265eb06
    Kees Cook authored
    Without visibility into the initializers for data->innr, GCC suspects
    using it as an index could walk off the end of the various 14-element
    arrays in data. Perform an explicit clamp to the array size. Silences
    the following warning with GCC 12+:
    
    ../drivers/hwmon/pc87360.c: In function 'pc87360_update_device':
    ../drivers/hwmon/pc87360.c:341:49: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
      341 |                                 data->in_max[i] = pc87360_read_value(data,
          |                                 ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
      342 |                                                   LD_IN, i,
          |                                                   ~~~~~~~~~
      343 |                                                   PC87365_REG_IN_MAX);
          |                                                   ~~~~~~~~~~~~~~~~~~~
    ../drivers/hwmon/pc87360.c:209:12: note: at offset 255 into destination object 'in_max' of size 14
      209 |         u8 in_max[14];          /* Register value */
          |            ^~~~~~
    
    Cc: Jim Cromie <jim.cromie@gmail.com>
    Cc: Jean Delvare <jdelvare@suse.com>
    Cc: Guenter Roeck <linux@roeck-us.net>
    Cc: linux-hwmon@vger.kernel.org
    Signed-off-by: default avatarKees Cook <keescook@chromium.org>
    Reviewed-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
    Link: https://lore.kernel.org/r/20231130200207.work.679-kees@kernel.org
    [groeck: Added comment into code clarifying context]
    Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
    4265eb06
pc87360.c 50.9 KB