https://bugs.winehq.org/show_bug.cgi?id=36817
--- Comment #2 from Austin English austinenglish@gmail.com --- (In reply to Sebastian Lackner from comment #1)
Created attachment 48897 [details] msvcrt: Use MSVCRT_malloc instead of malloc in setvbuf (Valgrind).
This should fix it.
Yep, thanks.