===================================== WARNING: bad unlock balance detected! 5.5.0-rc1-syzkaller #0 Not tainted ------------------------------------- kworker/u4:0/7 is trying to release lock (&file->mut) at: [] ucma_event_handler+0x675/0xf90 drivers/infiniband/core/ucma.c:389 but there are no more locks to release! other info that might help us debug this: 4 locks held by kworker/u4:0/7: #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d56a5928 ((wq_completion)ib_addr){+.+.}, at: process_one_work+0x76f/0x15d0 kernel/workqueue.c:2235 #1: ffff8881da2ffdf0 ((work_completion)(&(&req->work)->work)){+.+.}, at: process_one_work+0x79f/0x15d0 kernel/workqueue.c:2239 #2: ffff8881c7140390 (&id_priv->handler_mutex){+.+.}, at: addr_handler+0xac/0x300 drivers/infiniband/core/cma.c:3059 #3: ffff8881bcf81260 (&file->mut){+.+.}, at: ucma_event_handler+0xa8/0xf90 drivers/infiniband/core/ucma.c:349 stack backtrace: CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.5.0-rc1-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+0x12f/0x187 lib/dump_stack.c:118 print_unlock_imbalance_bug.cold.53+0x114/0x123 kernel/locking/lockdep.c:4008 __lock_release kernel/locking/lockdep.c:4242 [inline] lock_release+0x5f6/0x900 kernel/locking/lockdep.c:4503 __mutex_unlock_slowpath+0x87/0x6a0 kernel/locking/mutex.c:1231 mutex_unlock+0x1b/0x30 kernel/locking/mutex.c:743 ucma_event_handler+0x675/0xf90 drivers/infiniband/core/ucma.c:389 addr_handler+0x23a/0x300 drivers/infiniband/core/cma.c:3092 process_one_req+0xdf/0x610 drivers/infiniband/core/addr.c:643 process_one_work+0x852/0x15d0 kernel/workqueue.c:2264 worker_thread+0x81/0xb80 kernel/workqueue.c:2410 kthread+0x334/0x3f0 kernel/kthread.c:255 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352