============================================ WARNING: possible recursive locking detected 6.11.0-rc3-syzkaller-00046-g82313624b2ae #0 Not tainted -------------------------------------------- kworker/0:1H/43 is trying to acquire lock: ffff888118f34148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x6e/0x120 kernel/workqueue.c:3876 but task is already holding lock: ffff888118f34148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((wq_completion)xillyusb); lock((wq_completion)xillyusb); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by kworker/0:1H/43: #0: ffff888118f34148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc900004e7d80 ((work_completion)(&xdev->wakeup_workitem)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 stack backtrace: CPU: 0 UID: 0 PID: 43 Comm: kworker/0:1H Not tainted 6.11.0-rc3-syzkaller-00046-g82313624b2ae #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: xillyusb wakeup_all Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain kernel/locking/lockdep.c:3855 [inline] __lock_acquire+0x2167/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 touch_wq_lockdep_map+0x78/0x120 kernel/workqueue.c:3876 __flush_workqueue+0x129/0x1200 kernel/workqueue.c:3918 drain_workqueue+0x18f/0x3d0 kernel/workqueue.c:4082 destroy_workqueue+0xc2/0xaa0 kernel/workqueue.c:5781 cleanup_dev+0xc5/0x150 drivers/char/xillybus/xillyusb.c:558 kref_put include/linux/kref.h:65 [inline] wakeup_all+0x28c/0x300 drivers/char/xillybus/xillyusb.c:612 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244