============================= WARNING: suspicious RCU usage 5.9.0-rc3-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/u16:0/27083: #0: ffff88807ab97938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88807ab97938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88807ab97938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88807ab97938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88807ab97938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88807ab97938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc9000495fda8 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 stack backtrace: CPU: 0 PID: 27083 Comm: kworker/u16:0 Not tainted 5.9.0-rc3-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Workqueue: qrtr_ns_handler qrtr_ns_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 radix_tree_deref_slot include/linux/radix-tree.h:176 [inline] radix_tree_deref_slot include/linux/radix-tree.h:174 [inline] ctrl_cmd_new_lookup+0x6d4/0x7c0 net/qrtr/ns.c:558 qrtr_ns_worker+0x5a9/0x14fc net/qrtr/ns.c:674 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 failed to send lookup notification