Comment by barco

There are multiple versions of HWAsan.

One for ARMv8 with Top-Byte-Ignore: you can use the top byte of memory addresses to store a tag.

When you allocate memory you return the "tagged" pointer and internally store "this region has this tag".

When you dereference a pointer, you check that the tag matches what you expect in your internal data structure.

With memory tagging extensions you can do something similar but the checks are performed by the processor.