Comment 5 for bug 1702240

You don't need to check with upstream e2fsprogs; I do keep an eye on Launchpad bugs.

None of UBSAN warnings are actually dangerous assuming sane[1] compilers and reasonable architecture. (e.g., a compiler that can correctly compile the Linux kernel and an architecture that run Linux should have no problems with e2fsprogs).

[1] "Any sufficiently advanced compiler is indistinguishable from a malicious adversary."

Still, it's better to fix these sorts of issues than not, so please see the attached patch. It will be included in the next release of e2fsprogs.