default or selected kernelversion does not have config value CONFIG_KMEMCHECK_PARTIAL_OK.
Result is shown for kernelversion 6.5.1

kmemcheck: allow partially uninitialized memory


Linux Kernel Configuration
└─>Memory Debugging
└─>kmemcheck: trap use of uninitialized memory
└─>kmemcheck: allow partially uninitialized memory
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  
This option works around certain GCC optimizations that produce
32-bit reads from 16-bit variables where the upper 16 bits are
thrown away afterwards. This may of course also hide some real