===================================== WARNING: bad unlock balance detected! 4.19.188-syzkaller #0 Not tainted ------------------------------------- kworker/u4:7/9571 is trying to release lock (&file->mut) at: [] ucma_event_handler+0x745/0xf50 drivers/infiniband/core/ucma.c:396 but there are no more locks to release! other info that might help us debug this: 4 locks held by kworker/u4:7/9571: #0: 00000000e165f43d ((wq_completion)"ib_addr"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2123 #1: 000000007e9541a3 ((work_completion)(&(&req->work)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2127 #2: 00000000fd86f2ec (&id_priv->handler_mutex){+.+.}, at: addr_handler+0xaf/0x5f0 drivers/infiniband/core/cma.c:2886 #3: 00000000851ce599 (&file->mut){+.+.}, at: ucma_event_handler+0xb2/0xf50 drivers/infiniband/core/ucma.c:356 stack backtrace: CPU: 1 PID: 9571 Comm: kworker/u4:7 Not tainted 4.19.188-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ib_addr process_one_req Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_unlock_imbalance_bug kernel/locking/lockdep.c:149 [inline] __lock_release kernel/locking/lockdep.c:3678 [inline] lock_release.cold+0xe/0x4a kernel/locking/lockdep.c:3926 __mutex_unlock_slowpath+0x89/0x610 kernel/locking/mutex.c:1200 ucma_event_handler+0x745/0xf50 drivers/infiniband/core/ucma.c:396 addr_handler+0x2c1/0x5f0 drivers/infiniband/core/cma.c:2919 process_one_req+0xf1/0x620 drivers/infiniband/core/addr.c:569 process_one_work+0x864/0x1570 kernel/workqueue.c:2152 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 encrypted_key: insufficient parameters specified Scheduler tracepoints stat_sleep, stat_iowait, stat_blocked and stat_runtime require the kernel parameter schedstats=enable or kernel.sched_schedstats=1