A reminder that we've had strlcpy[1] for ~ 30 years but it was never accepted into the Linux world because of typical petty open source bullshit. This is why we can't have nice things.
The Linux kernel had strlcpy over 20 years ago. It was removed in favor of strscpy because the latter was judged a better interface. Here's a 2022 article: https://lwn.net/Articles/905777/
Returning an error is better but you're using ssize_t which is a tradeoff.
The race conditions appear to be a result of the Linux kernel implementation but UNIX style syscalls introduce these races by default. It is not an inherent flaw of the API or even the implementation Linux was using.
The only useable C string API has always been memcpy anyways.
[1] https://man.openbsd.org/strlcpy