[strcat]

No, that's not at all the case. We made our own MTE implementation for our hardened_malloc project with significantly stronger security properties. We had to fix multiple bugs in the OS and with Chromium's MTE integration to enable it for Vanadium in PartitionAlloc. We do currently simply use the standard implementation in PartitionAlloc but we plan to improve that since it's missing security properties we have in hardened_malloc. We also had to implement a system for per-app MTE control and an MTE crash reporting system. The current kernel KASan MTE backend is inadequate for usage of MTE as a hardening feature so we either need to make our own implementation there too or convince others to do it and it's likely not going to be the latter.

ARM did the work of designing it and integrating it into their standard ARM Cortex core/cache designs. Google/Samsung did the work of preserving standard ARM functionality, unlike Qualcomm which currently loses it. Google/Samsung also had to integrate it into the boot chain. They'd already previously done most of the bug fixing work via testing with HWASan. It is certainly true that Google paved the way to use MTE with HWASan and did a lot of the bug fixing work in the OS but external security researchers did a lot of this work too.