From ff244303301f6f2ac90107c61d18826efd0af822 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Sun, 25 Apr 2021 01:26:03 +0200 Subject: [PATCH] kernel: always initialize task->pf_io_worker to NULL 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 Signed-off-by: Stefan Metzmacher Signed-off-by: Jens Axboe --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/fork.c b/kernel/fork.c index b81ccb1ca3a7d..224c8317df342 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); -- 2.30.2