Please backport 8542870237c3 ("md: fix mddev uaf while iterating all_mddevs list") back down to 6.12.y (and question on older stable series back to 6.1.y)

[Salvatore Bonaccorso <carnil@debian.org>]

Hi stable mantainers,

[note I'm CC'ing here Guillaume, Yu and Christoph]

In Debian we were affected for a while by
https://bugs.debian.org/1086175 which we found to be reported by
Guillaume as
https://lore.kernel.org/all/Z7Y0SURoA8xwg7vn@bender.morinfr.org/ .

The issue went in fact back to 6.0. The fix was applied upstream and
then backported to 6.14.2 already. Can you backport it please as well
down to the other stable series, at least back to 6.12.y it goes with
applying (and unless I miss something fixes the issue, we
cherry-picked the commit for Debian trixie and our 6.12.y kernel in
advance already).

For going back to 6.1.y it seems it won't apply cleanly, You,
Christoph might you be available to look into it to make this
possible?

Regards,
Salvatore