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.
I mean, we are deep into reading tea leaves at this point, but what it seems to have identified is the source file that changed such that this issue can now occur. My gut instinct is that the changed code is still valid and correct, but it exercises the hardware in a different or a more intense way.