My fun Linux kernel patch story from the early 00s is sending in what I thought was a carefully worked out patch to deal with a somewhat tricky 32-bit/64-bit NFS client compatibility issue, which vanished into the void of no comments. Some months later, Linus Torvalds made a change to fix the same problem except it was incomplete, missing one case my patch had dealt with.
(I assume Torvalds never even saw my patch in the mailing list volume, and probably no one else looked at it either.)