finding earliest tags descended from a given commit

Just curious: every now and then somebody will ask me what kernel version they need to upgrade to to get some given fix. I can find the commit with the given fix easily enough. How do I then find the earliest tagged version containing that fix?

More generally, given a commit, is there a quick way to find the set of tags which tag commits descended from the given commit? Or to get the subset of such tags which are earliest (in the sense that they're not descendants of any of the others)?

I usually just do

	git-describe <commit>

to make a guess, then

	git log <tag>..<commit>

to verify, but perhaps there's something more clever, or something that would work better in a project where the tags aren't necessarily all in a straight line.

--b.