The overflow would still overflow; the use-after-free would still use after free; a musl mask race would still race. 

Hilarious. Apart from the computer poetry, the conclusion seems to be “it’s something in Linux 7.0 + musl 1.2.5”, although the only reproduction is still on the same physical Threadripper CPU and only sometimes when heavily exercised, so it hasn’t really ruled out a hardware issue.