Otherwise io_wq_worker_{running,sleeping}() may dereference an
invalid pointer (in future). Currently all users of create_io_thread()
are fine and get task->pf_io_worker = NULL implicitly from the
wq_manager, which got it either from the userspace thread
of the sq_thread, which explicitly reset it to NULL.
I think it's safer to always reset it in order to avoid future
problems.
Fixes: 3bfe6106693b ("io-wq: fork worker threads from original task")
cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Stefan Metzmacher <metze@xxxxxxxxx>
---
kernel/fork.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/fork.c b/kernel/fork.c
index d3171e8e88e5..0b7068c55552 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -927,6 +927,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
tsk->splice_pipe = NULL;
tsk->task_frag.page = NULL;
tsk->wake_q.next = NULL;
+ tsk->pf_io_worker = NULL;
account_kernel_stack(tsk, 1);
--
2.25.1
