kthread() could bail out early before we initialize blkcg_css (if the
kthread is killed very early. Please see xchg() statement in kthread()),
which confuses free_kthread_struct. Instead of moving the blkcg_css
initialization early, we simply zero the whole 'self' data structure,
which doesn't sound much overhead.
Reported-by: syzbot <[email protected]>
Fixes: 05e3db95eb ("kthread: add a mechanism to store cgroup info")
Cc: Andrew Morton <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Shaohua Li <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Shaohua Li
e10237cc76