============================= WARNING: suspicious RCU usage 5.8.0-rc7-syzkaller #0 Not tainted ----------------------------- include/linux/radix-tree.h:176 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by kworker/u4:6/3754: #0: ffff88812b136138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88812b136138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88812b136138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x1de/0x5f0 kernel/workqueue.c:2240 #1: ffffc9000a24be70 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #1: ffffc9000a24be70 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #1: ffffc9000a24be70 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x1de/0x5f0 kernel/workqueue.c:2240 stack backtrace: CPU: 0 PID: 3754 Comm: kworker/u4:6 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: qrtr_ns_handler qrtr_ns_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xb3/0xec lib/dump_stack.c:118 radix_tree_deref_slot include/linux/radix-tree.h:176 [inline] ctrl_cmd_new_lookup+0x284/0x2b0 net/qrtr/ns.c:558 qrtr_ns_worker+0x11a/0x717 net/qrtr/ns.c:674 process_one_work+0x26a/0x5f0 kernel/workqueue.c:2269 worker_thread+0x38/0x380 kernel/workqueue.c:2415 kthread+0x148/0x170 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification failed to send lookup notification