indutny/libuv — comment on commit 7902602a989f0ff231da08679f7423a539c22ec0
File: src/win/util.c line 267
By bnoordhuis:

Okay, the issue is that `table` may not be assigned if the `uv__query_reg_data()` call for `header` fails. IOW it contains whatever random junk its stack slot contains and you're freeing that.