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

kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)


Linux Kernel Configuration
└─>Memory Debugging
└─>kmemcheck: trap use of uninitialized memory
└─>kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  
Select the number of shadow bytes to save along with each entry of
the queue. These bytes indicate what parts of an allocation are
initialized, uninitialized, etc. and will be displayed when an
error is detected to help the debugging of a particular problem.