Messages in this thread | | | Date | Thu, 25 Aug 2022 07:44:36 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH] cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all() |
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On Thu, Aug 25, 2022 at 05:38:38PM +0900, Tetsuo Handa wrote: > syzbot is hitting percpu_rwsem_assert_held(&cpu_hotplug_lock) warning at > cpuset_attach() [1], for commit 4f7e7236435ca0ab ("cgroup: Fix > threadgroup_rwsem <-> cpus_read_lock() deadlock") missed that > cpuset_attach() is also called from cgroup_attach_task_all(). > Add cpus_read_lock() like what cgroup_procs_write_start() does. > > Link: https://syzkaller.appspot.com/bug?extid=29d3a3b4d86c8136ad9e [1] > Reported-by: syzbot <syzbot+29d3a3b4d86c8136ad9e@syzkaller.appspotmail.com> > Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Fixes: 4f7e7236435ca0ab ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock")
Applied to cgroup/for-6.0-fixes and sent pull request.
> Waiting for test result from syzbot. Should we remove "static" from > cgroup_attach_lock() and call from cgroup_attach_task_all() ?
Yeah, that probably is better. Can you spin up a follow up patch?
Thanks.
-- tejun
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