leds: trigger: netdev: Move size check in set_device_name
authorChristian Marangi <ansuelsmth@gmail.com>
Sat, 7 Oct 2023 13:10:42 +0000 (15:10 +0200)
committerLee Jones <lee@kernel.org>
Wed, 1 Nov 2023 11:29:14 +0000 (11:29 +0000)
commit259e33cbb1712a7dd844fc9757661cc47cb0e39b
treea16e907bba7cdc5dc97709e2d098c7e8e6ab00ad
parent0ebdb7210943eb345992bea9892adbd15a206193
leds: trigger: netdev: Move size check in set_device_name

GCC 13.2 complains about array subscript 17 is above array bounds of
'char[16]' with IFNAMSIZ set to 16.

The warning is correct but this scenario is impossible.
set_device_name is called by device_name_store (store sysfs entry) and
netdev_trig_activate.

device_name_store already check if size is >= of IFNAMSIZ and return
-EINVAL. (making the warning scenario impossible)

netdev_trig_activate works on already defined interface, where the name
has already been checked and should already follow the condition of
strlen() < IFNAMSIZ.

Aside from the scenario being impossible, set_device_name can be
improved to both mute the warning and make the function safer.
To make it safer, move size check from device_name_store directly to
set_device_name and prevent any out of bounds scenario.

Cc: stable@vger.kernel.org
Fixes: 28a6a2ef18ad ("leds: trigger: netdev: refactor code setting device name")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309192035.GTJEEbem-lkp@intel.com/
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20231007131042.15032-1-ansuelsmth@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
drivers/leds/trigger/ledtrig-netdev.c