[Bug sanitizer/95279] UBSan doesn't seem to detect pointer overflow in certain cases

[frantisek at sumsal dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95279

--- Comment #3 from Frantisek Sumsal <frantisek at sumsal dot cz> ---
Original issue: https://github.com/systemd/systemd/issues/15583
Patch: https://github.com/systemd/systemd/pull/15860
Code in question:
https://github.com/systemd/systemd/blob/master/src/libsystemd/sd-bus/bus-message.c#L3068