[0/4,v3] bfq: Avoid use-after-free when moving processes between cgroups

Message

Jan Kara Jan. 12, 2022, 11:39 a.m. UTC

Hello,

here is the third version of my patches to fix use-after-free issues in BFQ
when processes with merged queues get moved to different cgroups. The patches
have survived some beating in my test VM but so far I fail to reproduce the
original KASAN reports so testing from people who can reproduce them is most
welcome. Kuai, can you please give these patches a run in your setup? Thanks
a lot for your help with fixing this!

Changed since v2:
* Improved handling of bfq queue splitting on move between cgroups
* Removed broken change to bfq_put_cooperator()

Changes since v1:
* Added fix for bfq_put_cooperator()
* Added fix to handle move between cgroups in bfq_merge_bio()

								Honza
Previous versions:
Link: http://lore.kernel.org/r/[e-mail] # v1
Link: http://lore.kernel.org/r/[e-mail] # v2