===================================== WARNING: bad unlock balance detected! 4.20.0-rc2+ #236 Not tainted ------------------------------------- kworker/u4:3/178 is trying to release lock (&file->mut) at: [] ucma_event_handler+0x788/0x1000 drivers/infiniband/core/ucma.c:394 but there are no more locks to release! other info that might help us debug this: 4 locks held by kworker/u4:3/178: #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000084555638 ((wq_completion)"ib_addr"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000000092dd7a ((work_completion)(&(&req->work)->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 00000000e2f83da3 (&id_priv->handler_mutex){+.+.}, at: addr_handler+0xed/0x420 drivers/infiniband/core/cma.c:2967 #3: 00000000285586a7 (&file->mut){+.+.}, at: ucma_event_handler+0x116/0x1000 drivers/infiniband/core/ucma.c:354 stack backtrace: CPU: 1 PID: 178 Comm: kworker/u4:3 Not tainted 4.20.0-rc2+ #236 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+0x244/0x39d lib/dump_stack.c:113 syz-executor1 (12102): /proc/12102/oom_adj is deprecated, please use /proc/12102/oom_score_adj instead. print_unlock_imbalance_bug.cold.48+0xcc/0xd8 kernel/locking/lockdep.c:3394 __lock_release kernel/locking/lockdep.c:3604 [inline] lock_release+0x720/0xa00 kernel/locking/lockdep.c:3863 __mutex_unlock_slowpath+0x102/0x8c0 kernel/locking/mutex.c:1197 ptrace attach of "/root/syz-executor0"[6053] was attempted by "/root/syz-executor0"[12126] mutex_unlock+0xd/0x10 kernel/locking/mutex.c:713 ucma_event_handler+0x788/0x1000 drivers/infiniband/core/ucma.c:394 addr_handler+0x305/0x420 drivers/infiniband/core/cma.c:2991 kobject: 'loop5' (00000000498ba32e): kobject_uevent_env kobject: 'loop5' (00000000498ba32e): fill_kobj_path: path = '/devices/virtual/block/loop5' process_one_req+0x1a9/0x920 drivers/infiniband/core/addr.c:643 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 kobject: 'loop0' (00000000c105c69d): kobject_uevent_env kobject: 'loop0' (00000000c105c69d): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (000000001834945e): kobject_uevent_env kobject: 'loop1' (000000001834945e): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop1' (000000001834945e): kobject_uevent_env kobject: 'loop1' (000000001834945e): fill_kobj_path: path = '/devices/virtual/block/loop1' worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kobject: 'loop0' (00000000c105c69d): kobject_uevent_env kobject: 'loop0' (00000000c105c69d): fill_kobj_path: path = '/devices/virtual/block/loop0' kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 kobject: 'loop2' (0000000083c29aab): kobject_uevent_env kobject: 'loop2' (0000000083c29aab): fill_kobj_path: path = '/devices/virtual/block/loop2' ptrace attach of "/root/syz-executor0"[6053] was attempted by "/root/syz-executor0"[12150] kobject: 'loop3' (00000000f6e9d044): kobject_uevent_env kobject: 'loop3' (00000000f6e9d044): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (00000000498ba32e): kobject_uevent_env kobject: 'loop5' (00000000498ba32e): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (000000001834945e): kobject_uevent_env kobject: 'loop1' (000000001834945e): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (00000000f6e9d044): kobject_uevent_env kobject: 'loop3' (00000000f6e9d044): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop0' (00000000c105c69d): kobject_uevent_env kobject: 'loop0' (00000000c105c69d): fill_kobj_path: path = '/devices/virtual/block/loop0'