net: ipv6: Drop NS packet if LL address is too long
net: ipv6: Drop NS packet if LL address is too long

This commit fixes the crash of echo_server from overflow in ICMPv6 NS
source link-layer address option.

Fixes #6235

Signed-off-by: Ruslan Mstoi <348dc8e8f10581f5bc17672b9c406a6d9fcc1430@intel.com>

punitvara/zephyr,zephyriot/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,explora26/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,nashif/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,punitvara/zephyr,explora26/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,mbolivar/zephyr,kraj/zephyr,explora26/zephyr,zephyriot/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,nashif/zephyr,zephyriot/zephyr,ldts/zephyr,Vudentz/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyriot/zephyr,explora26/zephyr,finikorg/zephyr,punitvara/zephyr,mbolivar/zephyr,mbolivar/zephyr,ldts/zephyr,mbolivar/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,zephyriot/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,ldts/zephyr,Vudentz/zephyr,kraj/zephyr