HWASAN detects against spatial and temporal memory errors; i.e. you have a pointer to memory that gets freed, and use it again (temporal), or a stack overrun in

HWASAN detects against spatial and temporal memory errors; i.e. you have a pointer to memory that gets freed, and use it again (temporal), or a stack overrun into nearby memory (spatial). Pointer Authentication is used to sign pointers to give them a kind of provenance, but it's largely used to protect against code reuse/control flow attacks (ROP is much more difficult because you cannot re-use arbitrary gadgets in the executable; the stack pointer is part of the pointer signature, so screwing with it results in termination if the signature doesn't check out.) They are both complimentary; you could use them both. HWASAN (using memory tagging) and pointer authentication use the unused upper bits of a virtual address to store their metadata. They are compatible, but this does mean combining them reduces the overall amount of bits available for pointer signatures. There is a recent paper discussing the use of pointer authentication to build more advanced defenses; it looks like it's worth a read, and some comparisons (including HWASAN) are available in Section 8: https://www.usenix.org/system/files/sec19fall_liljestrand_prepub.pdf https://www.usenix.org/system/files/sec19fall_liljestrand_pr...