在 2022/01/15 1:01, Jan Kara 写道:
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! Changes since v3: * Changed handling of bfq group move to handle the case when target of the merge has moved.
Hi, Jan The problem can still be reporduced... Do you implement this in patch 4? If so, I don't understand how you chieve this. For example: 3 bfqqs were merged: q1->q2->q3 If __bfq_bic_change_cgroup() is called with q2, the problem can be fixed. However, if __bfq_bic_change_cgroup() is called with q3, can the problem be fixed? Thanks, Kuai
Changes 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/20211223171425.3551-1-jack@xxxxxxx # v1 Link: http://lore.kernel.org/r/20220105143037.20542-1-jack@xxxxxxx # v2 Link: http://lore.kernel.org/r/20220112113529.6355-1-jack@xxxxxxx # v3 .
